LinuxLists.cc - [PATCH] printk-formats.txt documentation update

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Subject: Re: [PATCH] printk-formats.txt documentation update

On Sun, 2011-02-06 at 00:15 +0000, Andrew Murray wrote:
> From: Andrew Murray <[email protected]>
> This patch updates the incomplete documentation concerning the printk
> extended format specifiers.
> Signed-off-by: Andrew Murray <[email protected]>
> ---
> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
[]
> @@ -9,7 +9,42 @@ If variable is of Type, use printk format specifier:
> size_t %zu or %zx
> ssize_t %zd or %zx
>
> -Raw pointer value SHOULD be printed with %p.
> +Raw pointer value SHOULD be printed with %p. The kernel supports
> +the following extended format specifiers for pointer types:

I think it'd be better if each extension were individually described
with an example output.

> +
> + General:
> +
> + %pF function pointer with offset, e.g. module_start
> + %pf function pointer without offset, e.g. module_start+0x0/0x62 [hello]

with/without inversion?

> + %pS text symbol with offset
> + %ps text symbol without offset
> + %pR struct resource with decoded flags, e.g. [mem 0x0-0x1f 64 bit pref]
> + %pr struct resource with raw flags, e.g. [mem 0x0-0x1f flags 0x201]
> +
> + MAC/FDDI addresses:
> +
> + %pM colon-seperated 6-byte MAC address in hex notation, e.g. 00:01:02:03:04:05

spelling: separated

> + %pm non-colon-seperated 6-byte MAC address is hex notation, e.g. 000102030405
> + %pMF 6-byte dash-separated FDDI hex notation
> +
> + IPv4 addresses:
> +
> + %pI4 IPv4 dot-seperated decimal without leading 0's, e.g. 1.2.3.4
> + %pi4 IPv4 dot-seperated decimal with leading 0's, 001.002.003.004
> + %p[Ii]4[hl] IPv4 dot-seperated decimal with/without leading 0's for
> + host (h), little (l) or network/big (default) endian order
> +
> + IPv6 addresses:
> + %pI6 IPv6 colon-seperated network-order 16 bit hex with leading 0's,
> + e.g. 0001:0203:...:0708
> + %pi6 IPv6 non-colon-seperated network-order 16 bit hex with leading 0's,
> + e.g. 000102...0f
> + %pI6c IPv6 address as described by
> + http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00,
> + e.g. 1::708
> +
> + %pU[bBlL] 16 byte UUID/GUID in big or little endian using lower or upper case

Maybe a simple 2 line table without the e.g.:

%p<extension1> sample output1
description1
%p<extension2> sample output2
description2

2011-02-06 10:07:50

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Subject: Re: [PATCH] printk-formats.txt documentation update

Thanks for the feedback - I will truncate to 80 characters and
implement Joe's advice.

Thanks,

Andrew Murray

On 6 February 2011 00:37, Joe Perches <[email protected]> wrote:
> On Sun, 2011-02-06 at 00:15 +0000, Andrew Murray wrote:
>> From: Andrew Murray <[email protected]>
>> This patch updates the incomplete documentation concerning the printk
>> extended format specifiers.
>> Signed-off-by: Andrew Murray <[email protected]>
>> ---
>> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
> []
>> @@ -9,7 +9,42 @@ If variable is of Type, use printk format specifier:
>> size_t %zu or %zx
>> ssize_t %zd or %zx
>>
>> -Raw pointer value SHOULD be printed with %p.
>> +Raw pointer value SHOULD be printed with %p. The kernel supports
>> +the following extended format specifiers for pointer types:
>
> I think it'd be better if each extension were individually described
> with an example output.
>
>> +
>> + General:
>> +
>> + %pF function pointer with offset, e.g. module_start
>> + %pf function pointer without offset, e.g. module_start+0x0/0x62 [hello]
>
> with/without inversion?
>
>> + %pS text symbol with offset
>> + %ps text symbol without offset
>> + %pR struct resource with decoded flags, e.g. [mem 0x0-0x1f 64 bit pref]
>> + %pr struct resource with raw flags, e.g. [mem 0x0-0x1f flags 0x201]
>> +
>> + MAC/FDDI addresses:
>> +
>> + %pM colon-seperated 6-byte MAC address in hex notation, e.g. 00:01:02:03:04:05
>
> spelling: separated
>
>> + %pm non-colon-seperated 6-byte MAC address is hex notation, e.g. 000102030405
>> + %pMF 6-byte dash-separated FDDI hex notation
>> +
>> + IPv4 addresses:
>> +
>> + %pI4 IPv4 dot-seperated decimal without leading 0's, e.g. 1.2.3.4
>> + %pi4 IPv4 dot-seperated decimal with leading 0's, 001.002.003.004
>> + %p[Ii]4[hl] IPv4 dot-seperated decimal with/without leading 0's for
>> + host (h), little (l) or network/big (default) endian order
>> +
>> + IPv6 addresses:
>> + %pI6 IPv6 colon-seperated network-order 16 bit hex with leading 0's,
>> + e.g. 0001:0203:...:0708
>> + %pi6 IPv6 non-colon-seperated network-order 16 bit hex with leading 0's,
>> + e.g. 000102...0f
>> + %pI6c IPv6 address as described by
>> + http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00,
>> + e.g. 1::708
>> +
>> + %pU[bBlL] 16 byte UUID/GUID in big or little endian using lower or upper case
>
> Maybe a simple 2 line table without the e.g.:
>
> %p<extension1> sample output1
> description1
> %p<extension2> sample output2
> description2
>
>
>

--
Andrew Murray, Embedded Linux Group
MPC Data Limited
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2011-02-06 10:16:36

by Geert Uytterhoeven

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Subject: Re: [PATCH] printk-formats.txt documentation update

On Sun, Feb 6, 2011 at 01:15, Andrew Murray <[email protected]> wrote:
> From: Andrew Murray <[email protected]>
>
> This patch updates the incomplete documentation concerning the printk
> extended format specifiers.
>
> Signed-off-by: Andrew Murray <[email protected]>
> ---
> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
> index 1b5a5dd..df14336 100644
> --- a/Documentation/printk-formats.txt
> +++ b/Documentation/printk-formats.txt
> @@ -9,7 +9,42 @@ If variable is of Type, use printk format specifier:
> size_t %zu or %zx
> ssize_t %zd or %zx
>
> -Raw pointer value SHOULD be printed with %p.
> +Raw pointer value SHOULD be printed with %p. The kernel supports
> +the following extended format specifiers for pointer types:
> +
> + General:
> +
> + %pF function pointer with offset, e.g. module_start
> + %pf function pointer without offset, e.g. module_start+0x0/0x62 [hello]
> + %pS text symbol with offset
> + %ps text symbol without offset
> + %pR struct resource with decoded flags, e.g. [mem 0x0-0x1f 64 bit pref]
> + %pr struct resource with raw flags, e.g. [mem 0x0-0x1f flags 0x201]
> +
> + MAC/FDDI addresses:
> +
> + %pM colon-seperated 6-byte MAC address in hex notation, e.g. 00:01:02:03:04:05
> + %pm non-colon-seperated 6-byte MAC address is hex notation, e.g. 000102030405
> + %pMF 6-byte dash-separated FDDI hex notation
> +
> + IPv4 addresses:
> +
> + %pI4 IPv4 dot-seperated decimal without leading 0's, e.g. 1.2.3.4
> + %pi4 IPv4 dot-seperated decimal with leading 0's, 001.002.003.004
> + %p[Ii]4[hl] IPv4 dot-seperated decimal with/without leading 0's for
> + host (h), little (l) or network/big (default) endian order
> +
> + IPv6 addresses:
> + %pI6 IPv6 colon-seperated network-order 16 bit hex with leading 0's,
> + e.g. 0001:0203:...:0708
> + %pi6 IPv6 non-colon-seperated network-order 16 bit hex with leading 0's,
> + e.g. 000102...0f
> + %pI6c IPv6 address as described by
> + http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00,
> + e.g. 1::708
> +
> + %pU[bBlL] 16 byte UUID/GUID in big or little endian using lower or upper case
> +

In the mean time, we also got %pV and %pK. Can you please add them as well? Thx!

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

2011-02-06 16:14:53

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Subject: Re: [PATCH] printk-formats.txt documentation update

On 6 February 2011 10:16, Geert Uytterhoeven <[email protected]> wrote:
> In the mean time, we also got %pV and %pK. Can you please add them as well? Thx!

Ok how about this revised patch?

From: Andrew Murray <[email protected]>

This patch updates the incomplete documentation concerning the printk
extended format specifiers.

Signed-off-by: Andrew Murray <[email protected]>
---
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 1b5a5dd..cad0dda 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -1,4 +1,4 @@
-If variable is of Type, use printk format specifier:
+f variable is of Type, use printk format specifier:
---------------------------------------------------------
int %d or %x
unsigned int %u or %x
@@ -9,7 +9,111 @@ If variable is of Type, use printk format specifier:
size_t %zu or %zx
ssize_t %zd or %zx

-Raw pointer value SHOULD be printed with %p.
+Raw pointer value SHOULD be printed with %p. The kernel supports
+the following extended format specifiers for pointer types:
+
+Symbols/Function Pointers:
+
+ %pF versatile_init+0x0/0x110
+ %pf versatile_init
+ %pS versatile_init+0x0/0x110
+ %ps versatile_init
+
+ For printing symbols and function pointers. The 'S' and 's' specifiers
+ result in the symbol name with ('S') or without ('s') offsets. Where
+ this is used on a kernel without KALLSYMS - the symbol address is
+ printed instead.
+
+ On ia64, ppc64 and parisc64 architectures function pointers are
+ actually function descriptors which must first be resolved. The 'F' and
+ 'f' specifiers perform this resolution and then provide the same
+ functionality as the 'S' and 's' specifiers.
+
+Kernel Pointers:
+
+ %pK 0x0
+
+ For printing kernel pointers which should be hidden from unprivileged
+ users. The behaviour of %pK depends on the kptr_resrict sysctl - see
+ Documentation/sysctl/kernel.txt for more details.
+
+Struct Resources:
+
+ %pr [mem 0x60000000-0x6fffffff flags 0x2200]
+ %pR [mem 0x60000000-0x6fffffff pref]
+
+ For printing struct resources. The 'R' and 'r' specifiers result in a
+ printed resource with ('R') or without ('r') a decoded flags member.
+
+MAC/FDDI addresses:
+
+ %pM 00:01:02:03:04:05
+ %pMF 00-01-02-03-04-05
+ %pm 000102030405
+
+ For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
+ specifiers result in a printed address with ('M') or without ('m') byte
+ seperators. The default byte seperator is the colon (':').
+
+ Where FDDI addresses are concerned the 'F' specifier can be used after
+ the 'M' specifier to use dash ('-') seperators instead of the default
+ seperator.
+
+IPv4 addresses:
+
+ %pI4 1.2.3.4
+ %pi4 001.002.003.004
+ %p[Ii][hnbl]
+
+ For printing IPv4 dot-seperated decminal addresses. The 'I4' and 'i4'
+ specifiers result in a printed address with ('i4') or without ('I4')
+ leading zeros.
+
+ The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
+ host, network, big or little endian order addresses respectively. Where
+ no specifier is provided the default network/big endian order is used.
+
+IPv6 addresses:
+
+ %pI6 0001:0002:0003:0004:0005:0006:0007:0008
+ %pi6 00010002000300040005000600070008
+ %pI6c 1:2:3:4:5:6:7:8
+
+ For printing IPv6 network-order 16 bit hex addresses. The 'I6' and 'i6'
+ specifiers result in a printed address with ('I6') or without ('i6')
+ colon-seperaters. Leading zeros are always used.
+
+ The additional 'c' specifier can be used with the 'I' specifier to
+ print a compressed IPv6 address as described by
+ http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00.
+
+UUID/GUID addresses:
+
+ %pU 00010203-0506-0708-090a-0b0c0d0e0fff
+ %pU[bBlL]
+
+ For printing 16 byte UUID/GUIDs addresses. The additional 'l', 'L',
+ 'b' and 'B' specifiers are used to specifiy a little endian order in
+ lower ('l') or upper case ('L') hex characters - and big endian order
+ in lower ('b') or upper case ('B') hex characters.
+
+ Where no additional specifiers are used the default little endian
+ order with lower case hex characters will be printed.
+
+struct va_format:
+
+ %pV
+
+ For printing struct va_format structures. These contain a format string
+ and va_list as follows:
+
+ struct va_format {
+ const char *fmt;
+ va_lost *va;
+ };
+
+ Do not use this feature without some mechanism to verify the
+ correctness of the format string and va_list arguments.

u64 SHOULD be printed with %llu/%llx, (unsigned long long):

@@ -32,4 +136,5 @@ Reminder: sizeof() result is of type size_t.
Thank you for your cooperation and attention.

-By Randy Dunlap <[email protected]>
+By Randy Dunlap <[email protected]> and
+Andrew Murray <[email protected]>

2011-02-06 16:23:12

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

On 6 February 2011 16:14, Andrew Murray <[email protected]> wrote:
> On 6 February 2011 10:16, Geert Uytterhoeven <[email protected]> wrote:
>> In the mean time, we also got %pV and %pK. Can you please add them as well? Thx!
>
> Ok how about this revised patch?
>
I've just noticed a zillion spelling mistakes - find below another
revised patch.

From: Andrew Murray <[email protected]>

This patch updates the incomplete documentation concerning the printk
extended format specifiers.

Signed-off-by: Andrew Murray <[email protected]>
---
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 1b5a5dd..cad0dda 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -1,4 +1,4 @@
-If variable is of Type, use printk format specifier:
+f variable is of Type, use printk format specifier:
---------------------------------------------------------
int %d or %x
unsigned int %u or %x
@@ -9,7 +9,111 @@ If variable is of Type, use printk format specifier:
size_t %zu or %zx
ssize_t %zd or %zx

-Raw pointer value SHOULD be printed with %p.
+Raw pointer value SHOULD be printed with %p. The kernel supports
+the following extended format specifiers for pointer types:
+
+Symbols/Function Pointers:
+
+ %pF versatile_init+0x0/0x110
+ %pf versatile_init
+ %pS versatile_init+0x0/0x110
+ %ps versatile_init
+
+ For printing symbols and function pointers. The 'S' and 's' specifiers
+ result in the symbol name with ('S') or without ('s') offsets. Where
+ this is used on a kernel without KALLSYMS - the symbol address is
+ printed instead.
+
+ On ia64, ppc64 and parisc64 architectures function pointers are
+ actually function descriptors which must first be resolved. The 'F' and
+ 'f' specifiers perform this resolution and then provide the same
+ functionality as the 'S' and 's' specifiers.
+
+Kernel Pointers:
+
+ %pK 0x0
+
+ For printing kernel pointers which should be hidden from unprivileged
+ users. The behaviour of %pK depends on the kptr_resrict sysctl - see
+ Documentation/sysctl/kernel.txt for more details.
+
+Struct Resources:
+
+ %pr [mem 0x60000000-0x6fffffff flags 0x2200]
+ %pR [mem 0x60000000-0x6fffffff pref]
+
+ For printing struct resources. The 'R' and 'r' specifiers result in a
+ printed resource with ('R') or without ('r') a decoded flags member.
+
+MAC/FDDI addresses:
+
+ %pM 00:01:02:03:04:05
+ %pMF 00-01-02-03-04-05
+ %pm 000102030405
+
+ For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
+ specifiers result in a printed address with ('M') or without ('m') byte
+ separators. The default byte separator is the colon (':').
+
+ Where FDDI addresses are concerned the 'F' specifier can be used after
+ the 'M' specifier to use dash ('-') separators instead of the default
+ separator.
+
+IPv4 addresses:
+
+ %pI4 1.2.3.4
+ %pi4 001.002.003.004
+ %p[Ii][hnbl]
+
+ For printing IPv4 dot-separated decimal addresses. The 'I4' and 'i4'
+ specifiers result in a printed address with ('i4') or without ('I4')
+ leading zeros.
+
+ The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
+ host, network, big or little endian order addresses respectively. Where
+ no specifier is provided the default network/big endian order is used.
+
+IPv6 addresses:
+
+ %pI6 0001:0002:0003:0004:0005:0006:0007:0008
+ %pi6 00010002000300040005000600070008
+ %pI6c 1:2:3:4:5:6:7:8
+
+ For printing IPv6 network-order 16 bit hex addresses. The 'I6' and 'i6'
+ specifiers result in a printed address with ('I6') or without ('i6')
+ colon-separators. Leading zeros are always used.
+
+ The additional 'c' specifier can be used with the 'I' specifier to
+ print a compressed IPv6 address as described by
+ http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00.
+
+UUID/GUID addresses:
+
+ %pU 00010203-0506-0708-090a-0b0c0d0e0fff
+ %pU[bBlL]
+
+ For printing 16 byte UUID/GUIDs addresses. The additional 'l', 'L',
+ 'b' and 'B' specifiers are used to specify a little endian order in
+ lower ('l') or upper case ('L') hex characters - and big endian order
+ in lower ('b') or upper case ('B') hex characters.
+
+ Where no additional specifiers are used the default little endian
+ order with lower case hex characters will be printed.
+
+struct va_format:
+
+ %pV
+
+ For printing struct va_format structures. These contain a format string
+ and va_list as follows:
+
+ struct va_format {
+ const char *fmt;
+ va_lost *va;
+ };
+
+ Do not use this feature without some mechanism to verify the
+ correctness of the format string and va_list arguments.

u64 SHOULD be printed with %llu/%llx, (unsigned long long):

@@ -32,4 +136,5 @@ Reminder: sizeof() result is of type size_t.
Thank you for your cooperation and attention.

-By Randy Dunlap <[email protected]>
+By Randy Dunlap <[email protected]> and
+Andrew Murray <[email protected]>

2011-02-07 09:29:36

by Wolfram Sang

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

On Sun, Feb 06, 2011 at 04:23:09PM +0000, Andrew Murray wrote:
> On 6 February 2011 16:14, Andrew Murray <[email protected]> wrote:
> From: Andrew Murray <[email protected]>
>
> This patch updates the incomplete documentation concerning the printk
> extended format specifiers.

Good one, thanks!

> +Kernel Pointers:
> +
> + %pK 0x0
> +
> + For printing kernel pointers which should be hidden from unprivileged
> + users. The behaviour of %pK depends on the kptr_resrict sysctl - see

Typo: Should be kptr_restrict.

Regards,

Wolfram

--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |

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2011-02-07 18:14:00

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Subject: Re: [PATCH] printk-formats.txt documentation update

On 7 February 2011 09:29, Wolfram Sang <[email protected]> wrote:
> On Sun, Feb 06, 2011 at 04:23:09PM +0000, Andrew Murray wrote:
>> +
>> + For printing kernel pointers which should be hidden from unprivileged
>> + users. The behaviour of %pK depends on the kptr_resrict sysctl - see
>
> Typo: Should be kptr_restrict.

Updated patch:

From: Andrew Murray <[email protected]>

This patch updates the incomplete documentation concerning the printk
extended format specifiers.

Signed-off-by: Andrew Murray <[email protected]>
---
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 1b5a5dd..cad0dda 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -1,4 +1,4 @@
-If variable is of Type, use printk format specifier:
+f variable is of Type, use printk format specifier:
---------------------------------------------------------
int %d or %x
unsigned int %u or %x
@@ -9,7 +9,111 @@ If variable is of Type, use printk format specifier:
size_t %zu or %zx
ssize_t %zd or %zx

-Raw pointer value SHOULD be printed with %p.
+Raw pointer value SHOULD be printed with %p. The kernel supports
+the following extended format specifiers for pointer types:
+
+Symbols/Function Pointers:
+
+ %pF versatile_init+0x0/0x110
+ %pf versatile_init
+ %pS versatile_init+0x0/0x110
+ %ps versatile_init
+
+ For printing symbols and function pointers. The 'S' and 's' specifiers
+ result in the symbol name with ('S') or without ('s') offsets. Where
+ this is used on a kernel without KALLSYMS - the symbol address is
+ printed instead.
+
+ On ia64, ppc64 and parisc64 architectures function pointers are
+ actually function descriptors which must first be resolved. The 'F' and
+ 'f' specifiers perform this resolution and then provide the same
+ functionality as the 'S' and 's' specifiers.
+
+Kernel Pointers:
+
+ %pK 0x0
+
+ For printing kernel pointers which should be hidden from unprivileged
+ users. The behaviour of %pK depends on the kptr_restrict sysctl - see
+ Documentation/sysctl/kernel.txt for more details.
+
+Struct Resources:
+
+ %pr [mem 0x60000000-0x6fffffff flags 0x2200]
+ %pR [mem 0x60000000-0x6fffffff pref]
+
+ For printing struct resources. The 'R' and 'r' specifiers result in a
+ printed resource with ('R') or without ('r') a decoded flags member.
+
+MAC/FDDI addresses:
+
+ %pM 00:01:02:03:04:05
+ %pMF 00-01-02-03-04-05
+ %pm 000102030405
+
+ For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
+ specifiers result in a printed address with ('M') or without ('m') byte
+ separators. The default byte separator is the colon (':').
+
+ Where FDDI addresses are concerned the 'F' specifier can be used after
+ the 'M' specifier to use dash ('-') separators instead of the default
+ separator.
+
+IPv4 addresses:
+
+ %pI4 1.2.3.4
+ %pi4 001.002.003.004
+ %p[Ii][hnbl]
+
+ For printing IPv4 dot-separated decimal addresses. The 'I4' and 'i4'
+ specifiers result in a printed address with ('i4') or without ('I4')
+ leading zeros.
+
+ The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
+ host, network, big or little endian order addresses respectively. Where
+ no specifier is provided the default network/big endian order is used.
+
+IPv6 addresses:
+
+ %pI6 0001:0002:0003:0004:0005:0006:0007:0008
+ %pi6 00010002000300040005000600070008
+ %pI6c 1:2:3:4:5:6:7:8
+
+ For printing IPv6 network-order 16 bit hex addresses. The 'I6' and 'i6'
+ specifiers result in a printed address with ('I6') or without ('i6')
+ colon-separators. Leading zeros are always used.
+
+ The additional 'c' specifier can be used with the 'I' specifier to
+ print a compressed IPv6 address as described by
+ http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00.
+
+UUID/GUID addresses:
+
+ %pU 00010203-0506-0708-090a-0b0c0d0e0fff
+ %pU[bBlL]
+
+ For printing 16 byte UUID/GUIDs addresses. The additional 'l', 'L',
+ 'b' and 'B' specifiers are used to specify a little endian order in
+ lower ('l') or upper case ('L') hex characters - and big endian order
+ in lower ('b') or upper case ('B') hex characters.
+
+ Where no additional specifiers are used the default little endian
+ order with lower case hex characters will be printed.
+
+struct va_format:
+
+ %pV
+
+ For printing struct va_format structures. These contain a format string
+ and va_list as follows:
+
+ struct va_format {
+ const char *fmt;
+ va_lost *va;
+ };
+
+ Do not use this feature without some mechanism to verify the
+ correctness of the format string and va_list arguments.

u64 SHOULD be printed with %llu/%llx, (unsigned long long):

@@ -32,4 +136,5 @@ Reminder: sizeof() result is of type size_t.
Thank you for your cooperation and attention.

-By Randy Dunlap <[email protected]>
+By Randy Dunlap <[email protected]> and
+Andrew Murray <[email protected]>

2011-02-07 19:33:27

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

On Mon, 2011-02-07 at 18:12 +0000, Andrew Murray wrote:
> On 7 February 2011 09:29, Wolfram Sang <[email protected]> wrote:
> > On Sun, Feb 06, 2011 at 04:23:09PM +0000, Andrew Murray wrote:
> >> +
> >> + For printing kernel pointers which should be hidden from unprivileged
> >> + users. The behaviour of %pK depends on the kptr_resrict sysctl - see
> >
> > Typo: Should be kptr_restrict.
> Updated patch:

trivia:

> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
[]
> +Kernel Pointers:
> +
> + %pK 0x0

Bad example, leading zeros are emitted.

%pK 0x01234567 or 0x01234567890abcdef

depending on 32/64 bit. For 2.6.38, output should be 0x00000000
for a 0 if kptr_restrict is set, "(null)" or value otherwise.

> + For printing kernel pointers which should be hidden from unprivileged
> + users. The behaviour of %pK depends on the kptr_restrict sysctl - see
> + Documentation/sysctl/kernel.txt for more details.
> +
> +Struct Resources:
> +
> + %pr [mem 0x60000000-0x6fffffff flags 0x2200]
> + %pR [mem 0x60000000-0x6fffffff pref]
> +
> + For printing struct resources. The 'R' and 'r' specifiers result in a
> + printed resource with ('R') or without ('r') a decoded flags member.

Same issue, mem resources are printed using sizeof(resource_size_t) * 2

> +IPv6 addresses:
> +
> + %pI6 0001:0002:0003:0004:0005:0006:0007:0008
> + %pi6 00010002000300040005000600070008
> + %pI6c 1:2:3:4:5:6:7:8
> +
> + For printing IPv6 network-order 16 bit hex addresses. The 'I6' and 'i6'
> + specifiers result in a printed address with ('I6') or without ('i6')
> + colon-separators. Leading zeros are always used.
> +
> + The additional 'c' specifier can be used with the 'I' specifier to
> + print a compressed IPv6 address as described by
> + http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00.

It's probably better to use:

http://tools.ietf.org/html/rfc5952

> +
> +UUID/GUID addresses:
> +
> + %pU 00010203-0506-0708-090a-0b0c0d0e0fff

What happened to 04?

It's probably easier/simpler to just show all possible
output styles. Assuming an in memory incrementing
16 byte array, output is:

%pU 00010203-0405-0607-08090a0b0c0d0e0f

> + %pU[bBlL]

%pUb 00010203-0405-0607-08090a0b0c0d0e0f
%pUB 00010203-0405-0607-08090A0B0C0D0E0F
%pUl 03020100-0504-0706-08090a0b0c0d0e0f
%pUL 03020100-0504-0706-08090A0B0E0D0E0F

> + For printing 16 byte UUID/GUIDs addresses. The additional 'l', 'L',
> + 'b' and 'B' specifiers are used to specify a little endian order in
> + lower ('l') or upper case ('L') hex characters - and big endian order
> + in lower ('b') or upper case ('B') hex characters.
> +
> + Where no additional specifiers are used the default little endian
> + order with lower case hex characters will be printed.
> +
> +struct va_format:
> +
> + %pV
> +
> + For printing struct va_format structures. These contain a format string
> + and va_list as follows:
> +
> + struct va_format {
> + const char *fmt;
> + va_lost *va;

va_list

2011-02-11 08:15:24

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

On 7 February 2011 19:33, Joe Perches <[email protected]> wrote:
>
> On Mon, 2011-02-07 at 18:12 +0000, Andrew Murray wrote:
> > On 7 February 2011 09:29, Wolfram Sang <[email protected]> wrote:
> > > On Sun, Feb 06, 2011 at 04:23:09PM +0000, Andrew Murray wrote:
> > >> +
>

Thanks for the feedback - I'll be on holiday shortly - so will have to
continue this when in return.

Andrew Murray

2011-06-09 17:34:04

[permalink] [raw]

Subject: [PATCH] Revised patch

Hi,

I've updated this patch based on your feedback. This covers all the recent feedback.

From: Andrew Murray <[email protected]>

This patch updates the incomplete documentation concerning the printk
extended format specifiers.

Signed-off-by: Andrew Murray <[email protected]>

---
Documentation/printk-formats.txt | 113 +++++++++++++++++++++++++++++++++++++-
1 files changed, 111 insertions(+), 2 deletions(-)

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 1b5a5dd..2968cbf 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -9,7 +9,115 @@ If variable is of Type, use printk format specifier:
size_t %zu or %zx
ssize_t %zd or %zx

-Raw pointer value SHOULD be printed with %p.
+Raw pointer value SHOULD be printed with %p. The kernel supports
+the following extended format specifiers for pointer types:
+
+Symbols/Function Pointers:
+
+ %pF versatile_init+0x0/0x110
+ %pf versatile_init
+ %pS versatile_init+0x0/0x110
+ %ps versatile_init
+
+ For printing symbols and function pointers. The 'S' and 's' specifiers
+ result in the symbol name with ('S') or without ('s') offsets. Where
+ this is used on a kernel without KALLSYMS - the symbol address is
+ printed instead.
+
+ On ia64, ppc64 and parisc64 architectures function pointers are
+ actually function descriptors which must first be resolved. The 'F' and
+ 'f' specifiers perform this resolution and then provide the same
+ functionality as the 'S' and 's' specifiers.
+
+Kernel Pointers:
+
+ %pK 0x01234567 or 0x0123456789abcdef
+
+ For printing kernel pointers which should be hidden from unprivileged
+ users. The behaviour of %pK depends on the kptr_restrict sysctl - see
+ Documentation/sysctl/kernel.txt for more details.
+
+Struct Resources:
+
+ %pr [mem 0x60000000-0x6fffffff flags 0x2200] or
+ [mem 0x0000000060000000-0x000000006fffffff flags 0x2200]
+ %pR [mem 0x60000000-0x6fffffff pref] or
+ [mem 0x0000000060000000-0x000000006fffffff pref]
+
+ For printing struct resources. The 'R' and 'r' specifiers result in a
+ printed resource with ('R') or without ('r') a decoded flags member.
+
+MAC/FDDI addresses:
+
+ %pM 00:01:02:03:04:05
+ %pMF 00-01-02-03-04-05
+ %pm 000102030405
+
+ For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
+ specifiers result in a printed address with ('M') or without ('m') byte
+ separators. The default byte separator is the colon (':').
+
+ Where FDDI addresses are concerned the 'F' specifier can be used after
+ the 'M' specifier to use dash ('-') separators instead of the default
+ separator.
+
+IPv4 addresses:
+
+ %pI4 1.2.3.4
+ %pi4 001.002.003.004
+ %p[Ii][hnbl]
+
+ For printing IPv4 dot-separated decimal addresses. The 'I4' and 'i4'
+ specifiers result in a printed address with ('i4') or without ('I4')
+ leading zeros.
+
+ The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
+ host, network, big or little endian order addresses respectively. Where
+ no specifier is provided the default network/big endian order is used.
+
+IPv6 addresses:
+
+ %pI6 0001:0002:0003:0004:0005:0006:0007:0008
+ %pi6 00010002000300040005000600070008
+ %pI6c 1:2:3:4:5:6:7:8
+
+ For printing IPv6 network-order 16 bit hex addresses. The 'I6' and 'i6'
+ specifiers result in a printed address with ('I6') or without ('i6')
+ colon-separators. Leading zeros are always used.
+
+ The additional 'c' specifier can be used with the 'I' specifier to
+ print a compressed IPv6 address as described by
+ http://tools.ietf.org/html/rfc5952
+
+UUID/GUID addresses:
+
+ %pUb 00010203-0405-0607-0809-0a0b0c0d0e0f
+ %pUB 00010203-0405-0607-0809-0A0B0C0D0E0F
+ %pUl 03020100-0504-0706-0809-0a0b0c0e0e0f
+ %pUL 03020100-0504-0706-0809-0A0B0C0E0E0F
+
+ For printing 16 byte UUID/GUIDs addresses. The additional 'l', 'L',
+ 'b' and 'B' specifiers are used to specify a little endian order in
+ lower ('l') or upper case ('L') hex characters - and big endian order
+ in lower ('b') or upper case ('B') hex characters.
+
+ Where no additional specifiers are used the default little endian
+ order with lower case hex characters will be printed.
+
+struct va_format:
+
+ %pV
+
+ For printing struct va_format structures. These contain a format string
+ and va_list as follows:
+
+ struct va_format {
+ const char *fmt;
+ va_list *va;
+ };
+
+ Do not use this feature without some mechanism to verify the
+ correctness of the format string and va_list arguments.

u64 SHOULD be printed with %llu/%llx, (unsigned long long):

@@ -32,4 +140,5 @@ Reminder: sizeof() result is of type size_t.
Thank you for your cooperation and attention.

-By Randy Dunlap <[email protected]>
+By Randy Dunlap <[email protected]> and
+Andrew Murray <[email protected]>
--
1.7.4.1

2011-06-09 17:40:06

[permalink] [raw]

Subject: Re: [PATCH] Revised patch

On Thu, 2011-06-09 at 18:33 +0100, Andrew Murray wrote:
> Hi,
> I've updated this patch based on your feedback. This covers all the recent feedback.

Hey Andrew.

You're missing the "%pB" backtrace extension.

It's be better if the "Hi, I've updated" comment stuff
came after the --- content separator in the patch so that
the commit log is a bit neater.

Otherwise, looks great, thanks.

cheers, Joe

2011-06-09 17:47:25

[permalink] [raw]

Subject: Re: [PATCH] Revised patch

On Thu, 9 Jun 2011 18:33:46 +0100 Andrew Murray wrote:

> Hi,
>
> I've updated this patch based on your feedback. This covers all the recent feedback.
>
> From: Andrew Murray <[email protected]>
>
> This patch updates the incomplete documentation concerning the printk
> extended format specifiers.

Thanks. A few comments below...

> Signed-off-by: Andrew Murray <[email protected]>
>
> ---
> Documentation/printk-formats.txt | 113 +++++++++++++++++++++++++++++++++++++-
> 1 files changed, 111 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
> index 1b5a5dd..2968cbf 100644
> --- a/Documentation/printk-formats.txt
> +++ b/Documentation/printk-formats.txt
> @@ -9,7 +9,115 @@ If variable is of Type, use printk format specifier:
> size_t %zu or %zx
> ssize_t %zd or %zx
>
> -Raw pointer value SHOULD be printed with %p.
> +Raw pointer value SHOULD be printed with %p. The kernel supports
> +the following extended format specifiers for pointer types:
> +
> +Symbols/Function Pointers:
> +
> + %pF versatile_init+0x0/0x110
> + %pf versatile_init
> + %pS versatile_init+0x0/0x110
> + %ps versatile_init
> +
> + For printing symbols and function pointers. The 'S' and 's' specifiers
> + result in the symbol name with ('S') or without ('s') offsets. Where
> + this is used on a kernel without KALLSYMS - the symbol address is
> + printed instead.
> +
> + On ia64, ppc64 and parisc64 architectures function pointers are
> + actually function descriptors which must first be resolved. The 'F' and
> + 'f' specifiers perform this resolution and then provide the same
> + functionality as the 'S' and 's' specifiers.
> +
> +Kernel Pointers:
> +
> + %pK 0x01234567 or 0x0123456789abcdef
> +
> + For printing kernel pointers which should be hidden from unprivileged
> + users. The behaviour of %pK depends on the kptr_restrict sysctl - see
> + Documentation/sysctl/kernel.txt for more details.
> +
> +Struct Resources:
> +
> + %pr [mem 0x60000000-0x6fffffff flags 0x2200] or
> + [mem 0x0000000060000000-0x000000006fffffff flags 0x2200]
> + %pR [mem 0x60000000-0x6fffffff pref] or
> + [mem 0x0000000060000000-0x000000006fffffff pref]
> +
> + For printing struct resources. The 'R' and 'r' specifiers result in a
> + printed resource with ('R') or without ('r') a decoded flags member.
> +
> +MAC/FDDI addresses:
> +
> + %pM 00:01:02:03:04:05
> + %pMF 00-01-02-03-04-05
> + %pm 000102030405
> +
> + For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
> + specifiers result in a printed address with ('M') or without ('m') byte
> + separators. The default byte separator is the colon (':').
> +
> + Where FDDI addresses are concerned the 'F' specifier can be used after
> + the 'M' specifier to use dash ('-') separators instead of the default
> + separator.
> +
> +IPv4 addresses:
> +
> + %pI4 1.2.3.4
> + %pi4 001.002.003.004
> + %p[Ii][hnbl]
> +
> + For printing IPv4 dot-separated decimal addresses. The 'I4' and 'i4'
> + specifiers result in a printed address with ('i4') or without ('I4')
> + leading zeros.
> +
> + The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
> + host, network, big or little endian order addresses respectively. Where
> + no specifier is provided the default network/big endian order is used.
> +

I would hyphenate the -endian types, but won't insist on that.

> +IPv6 addresses:
> +
> + %pI6 0001:0002:0003:0004:0005:0006:0007:0008
> + %pi6 00010002000300040005000600070008
> + %pI6c 1:2:3:4:5:6:7:8
> +
> + For printing IPv6 network-order 16 bit hex addresses. The 'I6' and 'i6'

16-bit

> + specifiers result in a printed address with ('I6') or without ('i6')
> + colon-separators. Leading zeros are always used.
> +
> + The additional 'c' specifier can be used with the 'I' specifier to
> + print a compressed IPv6 address as described by
> + http://tools.ietf.org/html/rfc5952
> +
> +UUID/GUID addresses:
> +
> + %pUb 00010203-0405-0607-0809-0a0b0c0d0e0f
> + %pUB 00010203-0405-0607-0809-0A0B0C0D0E0F
> + %pUl 03020100-0504-0706-0809-0a0b0c0e0e0f
> + %pUL 03020100-0504-0706-0809-0A0B0C0E0E0F
> +
> + For printing 16 byte UUID/GUIDs addresses. The additional 'l', 'L',

16-byte

> + 'b' and 'B' specifiers are used to specify a little endian order in
> + lower ('l') or upper case ('L') hex characters - and big endian order
> + in lower ('b') or upper case ('B') hex characters.
> +
> + Where no additional specifiers are used the default little endian
> + order with lower case hex characters will be printed.
> +
> +struct va_format:
> +
> + %pV
> +
> + For printing struct va_format structures. These contain a format string
> + and va_list as follows:
> +
> + struct va_format {
> + const char *fmt;
> + va_list *va;
> + };
> +
> + Do not use this feature without some mechanism to verify the
> + correctness of the format string and va_list arguments.
>
> u64 SHOULD be printed with %llu/%llx, (unsigned long long):

%pB is missing?
* - 'B' For backtraced symbolic direct pointers with offset

> @@ -32,4 +140,5 @@ Reminder: sizeof() result is of type size_t.
> Thank you for your cooperation and attention.
>
>
> -By Randy Dunlap <[email protected]>
> +By Randy Dunlap <[email protected]> and
> +Andrew Murray <[email protected]>
> --

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

2011-06-09 17:47:40

by Namhyung Kim

[permalink] [raw]

Subject: Re: [PATCH] Revised patch

2011-06-09 (목), 10:40 -0700, Joe Perches:
> On Thu, 2011-06-09 at 18:33 +0100, Andrew Murray wrote:
> > Hi,
> > I've updated this patch based on your feedback. This covers all the recent feedback.
>
> Hey Andrew.
>
> You're missing the "%pB" backtrace extension.
>

http://marc.info/?l=linux-kernel&m=130093458112438&w=2

Just for your information. :)
Thanks.

--
Regards,
Namhyung Kim

2011-06-09 17:48:49

[permalink] [raw]

Subject: Re: [PATCH] Revised patch

Thanks - I've actually written the %pB documentation but just getting
in a mess with Git and my work flow - standby...

On 9 June 2011 18:47, Namhyung Kim <[email protected]> wrote:
> 2011-06-09 (목), 10:40 -0700, Joe Perches:
>> On Thu, 2011-06-09 at 18:33 +0100, Andrew Murray wrote:
>> > Hi,
>> > I've updated this patch based on your feedback. This covers all the recent feedback.
>>
>> Hey Andrew.
>>
>> You're missing the "%pB" backtrace extension.
>>
>
> http://marc.info/?l=linux-kernel&m=130093458112438&w=2
>
> Just for your information. :)
> Thanks.
>
>
> --
> Regards,
> Namhyung Kim
>
>
>

--
Andrew Murray, Embedded Linux Group
MPC Data Limited
e-mail: [email protected] web: http://www.mpc-data.co.uk
tel: +44 (0) 1225 710600 fax: +44 (0) 1225 710601
ddi: +44 (0) 1225 710665

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company number 05507446
Registered Address: County Gate, County Way, Trowbridge, Wiltshire, BA14 7FJ
VAT no: 850625238

The information in this email and in the attached documents is
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the terms and conditions expressed in the governing contract.

2011-06-09 17:53:56

[permalink] [raw]

Subject: Re: [PATCH] Revised patch

On Thu, 2011-06-09 at 10:47 -0700, Randy Dunlap wrote:
> On Thu, 9 Jun 2011 18:33:46 +0100 Andrew Murray wrote:
> > + For printing IPv6 network-order 16 bit hex addresses. The 'I6' and 'i6'
> 16-bit

byte. octet if pedantry is desired.

2011-06-09 18:06:19

[permalink] [raw]

Subject: [PATCH] printk-formats.txt documentation update

From: Andrew Murray <[email protected]>

This patch updates the incomplete documentation concerning the printk
extended format specifiers.

Signed-off-by: Andrew Murray <[email protected]>
---
Documentation/printk-formats.txt | 119 +++++++++++++++++++++++++++++++++++++-
1 files changed, 117 insertions(+), 2 deletions(-)

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 1b5a5dd..69713d6 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -9,7 +9,121 @@ If variable is of Type, use printk format specifier:
size_t %zu or %zx
ssize_t %zd or %zx

-Raw pointer value SHOULD be printed with %p.
+Raw pointer value SHOULD be printed with %p. The kernel supports
+the following extended format specifiers for pointer types:
+
+Symbols/Function Pointers:
+
+ %pF versatile_init+0x0/0x110
+ %pf versatile_init
+ %pS versatile_init+0x0/0x110
+ %ps versatile_init
+ %pB versatile_init+0x0/0x110
+
+ For printing symbols and function pointers. The 'S' and 's' specifiers
+ result in the symbol name with ('S') or without ('s') offsets. Where
+ this is used on a kernel without KALLSYMS - the symbol address is
+ printed instead.
+
+ The 'B' specifier results in the symbol name with offsets and should be
+ used when printing stack backtraces. The specifier takes into
+ consideration the effect of compiler optimisations which may occur
+ when tail-call's are used and marked with the noreturn GCC attribute.
+
+ On ia64, ppc64 and parisc64 architectures function pointers are
+ actually function descriptors which must first be resolved. The 'F' and
+ 'f' specifiers perform this resolution and then provide the same
+ functionality as the 'S' and 's' specifiers.
+
+Kernel Pointers:
+
+ %pK 0x01234567 or 0x0123456789abcdef
+
+ For printing kernel pointers which should be hidden from unprivileged
+ users. The behaviour of %pK depends on the kptr_restrict sysctl - see
+ Documentation/sysctl/kernel.txt for more details.
+
+Struct Resources:
+
+ %pr [mem 0x60000000-0x6fffffff flags 0x2200] or
+ [mem 0x0000000060000000-0x000000006fffffff flags 0x2200]
+ %pR [mem 0x60000000-0x6fffffff pref] or
+ [mem 0x0000000060000000-0x000000006fffffff pref]
+
+ For printing struct resources. The 'R' and 'r' specifiers result in a
+ printed resource with ('R') or without ('r') a decoded flags member.
+
+MAC/FDDI addresses:
+
+ %pM 00:01:02:03:04:05
+ %pMF 00-01-02-03-04-05
+ %pm 000102030405
+
+ For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
+ specifiers result in a printed address with ('M') or without ('m') byte
+ separators. The default byte separator is the colon (':').
+
+ Where FDDI addresses are concerned the 'F' specifier can be used after
+ the 'M' specifier to use dash ('-') separators instead of the default
+ separator.
+
+IPv4 addresses:
+
+ %pI4 1.2.3.4
+ %pi4 001.002.003.004
+ %p[Ii][hnbl]
+
+ For printing IPv4 dot-separated decimal addresses. The 'I4' and 'i4'
+ specifiers result in a printed address with ('i4') or without ('I4')
+ leading zeros.
+
+ The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
+ host, network, big or little endian order addresses respectively. Where
+ no specifier is provided the default network/big endian order is used.
+
+IPv6 addresses:
+
+ %pI6 0001:0002:0003:0004:0005:0006:0007:0008
+ %pi6 00010002000300040005000600070008
+ %pI6c 1:2:3:4:5:6:7:8
+
+ For printing IPv6 network-order 16-bit hex addresses. The 'I6' and 'i6'
+ specifiers result in a printed address with ('I6') or without ('i6')
+ colon-separators. Leading zeros are always used.
+
+ The additional 'c' specifier can be used with the 'I' specifier to
+ print a compressed IPv6 address as described by
+ http://tools.ietf.org/html/rfc5952
+
+UUID/GUID addresses:
+
+ %pUb 00010203-0405-0607-0809-0a0b0c0d0e0f
+ %pUB 00010203-0405-0607-0809-0A0B0C0D0E0F
+ %pUl 03020100-0504-0706-0809-0a0b0c0e0e0f
+ %pUL 03020100-0504-0706-0809-0A0B0C0E0E0F
+
+ For printing 16-byte UUID/GUIDs addresses. The additional 'l', 'L',
+ 'b' and 'B' specifiers are used to specify a little endian order in
+ lower ('l') or upper case ('L') hex characters - and big endian order
+ in lower ('b') or upper case ('B') hex characters.
+
+ Where no additional specifiers are used the default little endian
+ order with lower case hex characters will be printed.
+
+struct va_format:
+
+ %pV
+
+ For printing struct va_format structures. These contain a format string
+ and va_list as follows:
+
+ struct va_format {
+ const char *fmt;
+ va_list *va;
+ };
+
+ Do not use this feature without some mechanism to verify the
+ correctness of the format string and va_list arguments.

u64 SHOULD be printed with %llu/%llx, (unsigned long long):

@@ -32,4 +146,5 @@ Reminder: sizeof() result is of type size_t.
Thank you for your cooperation and attention.

-By Randy Dunlap <[email protected]>
+By Randy Dunlap <[email protected]> and
+Andrew Murray <[email protected]>
--
1.7.4.1

2011-06-09 18:21:00

by Namhyung Kim

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

2011-06-09 (목), 19:04 +0100, Andrew Murray:
> From: Andrew Murray <[email protected]>
>
> This patch updates the incomplete documentation concerning the printk
> extended format specifiers.
>
> Signed-off-by: Andrew Murray <[email protected]>
> ---
> Documentation/printk-formats.txt | 119 +++++++++++++++++++++++++++++++++++++-
> 1 files changed, 117 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
> index 1b5a5dd..69713d6 100644
> --- a/Documentation/printk-formats.txt
> +++ b/Documentation/printk-formats.txt
> @@ -9,7 +9,121 @@ If variable is of Type, use printk format specifier:
> size_t %zu or %zx
> ssize_t %zd or %zx
>
> -Raw pointer value SHOULD be printed with %p.
> +Raw pointer value SHOULD be printed with %p. The kernel supports
> +the following extended format specifiers for pointer types:
> +
> +Symbols/Function Pointers:
> +
> + %pF versatile_init+0x0/0x110
> + %pf versatile_init
> + %pS versatile_init+0x0/0x110
> + %ps versatile_init
> + %pB versatile_init+0x0/0x110
> +

-EBADEXAMPLE :)

If %pB is used, the offset part in the output could not be 0. That's the
key (and the only) difference of the %pB specifier than others. Thus the
output would be something like:

%pB prev_fn_of_versatile_init+0x88/0x88

Thanks.

--
Regards,
Namhyung Kim

2011-06-09 18:23:40

[permalink] [raw]

Subject: [PATCH] vsprintf: Update %pI6c to not compress a single 0

RFC 5952 http://tools.ietf.org/html/rfc5952
mandates that 2 or more consecutive 0's are
required before using :: compression.

Update ip6_compressed_string to match the RFC and
update the http reference as well.

Signed-off-by: Joe Perches <[email protected]>
---
lib/vsprintf.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c112056..4365df3 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -666,6 +666,8 @@ char *ip6_compressed_string(char *p, const char *addr)
colonpos = i;
}
}
+ if (longest == 1) /* don't compress a single 0 */
+ colonpos = -1;

/* emit address */
for (i = 0; i < range; i++) {
@@ -826,7 +828,7 @@ int kptr_restrict __read_mostly;
* IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
* - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
* - 'I6c' for IPv6 addresses printed as specified by
- * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
+ * http://tools.ietf.org/html/rfc5952
* - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
* "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
* Options for %pU are:
--
1.7.6.rc0

2011-06-09 18:55:55

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

From: Andrew Murray <[email protected]>

This patch updates the incomplete documentation concerning the printk
extended format specifiers

Signed-off-by: Andrew Murray <[email protected]>
---
Documentation/printk-formats.txt | 119 +++++++++++++++++++++++++++++++++++++-
1 files changed, 117 insertions(+), 2 deletions(-)

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 1b5a5dd..85a06aa 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -9,7 +9,121 @@ If variable is of Type, use printk format specifier:
size_t %zu or %zx
ssize_t %zd or %zx

-Raw pointer value SHOULD be printed with %p.
+Raw pointer value SHOULD be printed with %p. The kernel supports
+the following extended format specifiers for pointer types:
+
+Symbols/Function Pointers:
+
+ %pF versatile_init+0x0/0x110
+ %pf versatile_init
+ %pS versatile_init+0x0/0x110
+ %ps versatile_init
+ %pB prev_fn_of_versatile_init+0x88/0x88
+
+ For printing symbols and function pointers. The 'S' and 's' specifiers
+ result in the symbol name with ('S') or without ('s') offsets. Where
+ this is used on a kernel without KALLSYMS - the symbol address is
+ printed instead.
+
+ The 'B' specifier results in the symbol name with offsets and should be
+ used when printing stack backtraces. The specifier takes into
+ consideration the effect of compiler optimisations which may occur
+ when tail-call's are used and marked with the noreturn GCC attribute.
+
+ On ia64, ppc64 and parisc64 architectures function pointers are
+ actually function descriptors which must first be resolved. The 'F' and
+ 'f' specifiers perform this resolution and then provide the same
+ functionality as the 'S' and 's' specifiers.
+
+Kernel Pointers:
+
+ %pK 0x01234567 or 0x0123456789abcdef
+
+ For printing kernel pointers which should be hidden from unprivileged
+ users. The behaviour of %pK depends on the kptr_restrict sysctl - see
+ Documentation/sysctl/kernel.txt for more details.
+
+Struct Resources:
+
+ %pr [mem 0x60000000-0x6fffffff flags 0x2200] or
+ [mem 0x0000000060000000-0x000000006fffffff flags 0x2200]
+ %pR [mem 0x60000000-0x6fffffff pref] or
+ [mem 0x0000000060000000-0x000000006fffffff pref]
+
+ For printing struct resources. The 'R' and 'r' specifiers result in a
+ printed resource with ('R') or without ('r') a decoded flags member.
+
+MAC/FDDI addresses:
+
+ %pM 00:01:02:03:04:05
+ %pMF 00-01-02-03-04-05
+ %pm 000102030405
+
+ For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
+ specifiers result in a printed address with ('M') or without ('m') byte
+ separators. The default byte separator is the colon (':').
+
+ Where FDDI addresses are concerned the 'F' specifier can be used after
+ the 'M' specifier to use dash ('-') separators instead of the default
+ separator.
+
+IPv4 addresses:
+
+ %pI4 1.2.3.4
+ %pi4 001.002.003.004
+ %p[Ii][hnbl]
+
+ For printing IPv4 dot-separated decimal addresses. The 'I4' and 'i4'
+ specifiers result in a printed address with ('i4') or without ('I4')
+ leading zeros.
+
+ The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
+ host, network, big or little endian order addresses respectively. Where
+ no specifier is provided the default network/big endian order is used.
+
+IPv6 addresses:
+
+ %pI6 0001:0002:0003:0004:0005:0006:0007:0008
+ %pi6 00010002000300040005000600070008
+ %pI6c 1:2:3:4:5:6:7:8
+
+ For printing IPv6 network-order 16 bit hex addresses. The 'I6' and 'i6'
+ specifiers result in a printed address with ('I6') or without ('i6')
+ colon-separators. Leading zeros are always used.
+
+ The additional 'c' specifier can be used with the 'I' specifier to
+ print a compressed IPv6 address as described by
+ http://tools.ietf.org/html/rfc5952
+
+UUID/GUID addresses:
+
+ %pUb 00010203-0405-0607-0809-0a0b0c0d0e0f
+ %pUB 00010203-0405-0607-0809-0A0B0C0D0E0F
+ %pUl 03020100-0504-0706-0809-0a0b0c0e0e0f
+ %pUL 03020100-0504-0706-0809-0A0B0C0E0E0F
+
+ For printing 16 byte UUID/GUIDs addresses. The additional 'l', 'L',
+ 'b' and 'B' specifiers are used to specify a little endian order in
+ lower ('l') or upper case ('L') hex characters - and big endian order
+ in lower ('b') or upper case ('B') hex characters.
+
+ Where no additional specifiers are used the default little endian
+ order with lower case hex characters will be printed.
+
+struct va_format:
+
+ %pV
+
+ For printing struct va_format structures. These contain a format string
+ and va_list as follows:
+
+ struct va_format {
+ const char *fmt;
+ va_list *va;
+ };
+
+ Do not use this feature without some mechanism to verify the
+ correctness of the format string and va_list arguments.

u64 SHOULD be printed with %llu/%llx, (unsigned long long):

@@ -32,4 +146,5 @@ Reminder: sizeof() result is of type size_t.
Thank you for your cooperation and attention.

-By Randy Dunlap <[email protected]>
+By Randy Dunlap <[email protected]> and
+Andrew Murray <[email protected]>
--
1.7.4.1

2011-06-09 19:59:28

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

On Thu, 9 Jun 2011 19:55:35 +0100 Andrew Murray wrote:

> From: Andrew Murray <[email protected]>
>
> This patch updates the incomplete documentation concerning the printk
> extended format specifiers
>
> Signed-off-by: Andrew Murray <[email protected]>
> ---
> Documentation/printk-formats.txt | 119 +++++++++++++++++++++++++++++++++++++-
> 1 files changed, 117 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
> index 1b5a5dd..85a06aa 100644
> --- a/Documentation/printk-formats.txt
> +++ b/Documentation/printk-formats.txt
> @@ -9,7 +9,121 @@ If variable is of Type, use printk format specifier:
> size_t %zu or %zx
> ssize_t %zd or %zx
>
> -Raw pointer value SHOULD be printed with %p.
> +Raw pointer value SHOULD be printed with %p. The kernel supports
> +the following extended format specifiers for pointer types:
> +
> +Symbols/Function Pointers:
> +
> + %pF versatile_init+0x0/0x110
> + %pf versatile_init
> + %pS versatile_init+0x0/0x110
> + %ps versatile_init
> + %pB prev_fn_of_versatile_init+0x88/0x88
> +
> + For printing symbols and function pointers. The 'S' and 's' specifiers
> + result in the symbol name with ('S') or without ('s') offsets. Where
> + this is used on a kernel without KALLSYMS - the symbol address is
> + printed instead.
> +
> + The 'B' specifier results in the symbol name with offsets and should be
> + used when printing stack backtraces. The specifier takes into
> + consideration the effect of compiler optimisations which may occur
> + when tail-call's are used and marked with the noreturn GCC attribute.
> +
> + On ia64, ppc64 and parisc64 architectures function pointers are
> + actually function descriptors which must first be resolved. The 'F' and
> + 'f' specifiers perform this resolution and then provide the same
> + functionality as the 'S' and 's' specifiers.
> +
> +Kernel Pointers:
> +
> + %pK 0x01234567 or 0x0123456789abcdef
> +
> + For printing kernel pointers which should be hidden from unprivileged
> + users. The behaviour of %pK depends on the kptr_restrict sysctl - see
> + Documentation/sysctl/kernel.txt for more details.
> +
> +Struct Resources:
> +
> + %pr [mem 0x60000000-0x6fffffff flags 0x2200] or
> + [mem 0x0000000060000000-0x000000006fffffff flags 0x2200]
> + %pR [mem 0x60000000-0x6fffffff pref] or
> + [mem 0x0000000060000000-0x000000006fffffff pref]
> +
> + For printing struct resources. The 'R' and 'r' specifiers result in a
> + printed resource with ('R') or without ('r') a decoded flags member.
> +
> +MAC/FDDI addresses:
> +
> + %pM 00:01:02:03:04:05
> + %pMF 00-01-02-03-04-05
> + %pm 000102030405
> +
> + For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
> + specifiers result in a printed address with ('M') or without ('m') byte
> + separators. The default byte separator is the colon (':').
> +
> + Where FDDI addresses are concerned the 'F' specifier can be used after
> + the 'M' specifier to use dash ('-') separators instead of the default
> + separator.
> +
> +IPv4 addresses:
> +
> + %pI4 1.2.3.4
> + %pi4 001.002.003.004
> + %p[Ii][hnbl]
> +
> + For printing IPv4 dot-separated decimal addresses. The 'I4' and 'i4'
> + specifiers result in a printed address with ('i4') or without ('I4')
> + leading zeros.
> +
> + The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
> + host, network, big or little endian order addresses respectively. Where
> + no specifier is provided the default network/big endian order is used.
> +
> +IPv6 addresses:
> +
> + %pI6 0001:0002:0003:0004:0005:0006:0007:0008
> + %pi6 00010002000300040005000600070008
> + %pI6c 1:2:3:4:5:6:7:8
> +
> + For printing IPv6 network-order 16 bit hex addresses. The 'I6' and 'i6'

You lost the hyphen in 16-bit. The previous patch version had it... :(

> + specifiers result in a printed address with ('I6') or without ('i6')
> + colon-separators. Leading zeros are always used.
> +
> + The additional 'c' specifier can be used with the 'I' specifier to
> + print a compressed IPv6 address as described by
> + http://tools.ietf.org/html/rfc5952
> +
> +UUID/GUID addresses:
> +
> + %pUb 00010203-0405-0607-0809-0a0b0c0d0e0f
> + %pUB 00010203-0405-0607-0809-0A0B0C0D0E0F
> + %pUl 03020100-0504-0706-0809-0a0b0c0e0e0f
> + %pUL 03020100-0504-0706-0809-0A0B0C0E0E0F
> +
> + For printing 16 byte UUID/GUIDs addresses. The additional 'l', 'L',

same for 16-byte

> + 'b' and 'B' specifiers are used to specify a little endian order in
> + lower ('l') or upper case ('L') hex characters - and big endian order
> + in lower ('b') or upper case ('B') hex characters.
> +
> + Where no additional specifiers are used the default little endian
> + order with lower case hex characters will be printed.
> +
> +struct va_format:
> +
> + %pV
> +
> + For printing struct va_format structures. These contain a format string
> + and va_list as follows:
> +
> + struct va_format {
> + const char *fmt;
> + va_list *va;
> + };
> +
> + Do not use this feature without some mechanism to verify the
> + correctness of the format string and va_list arguments.
>
> u64 SHOULD be printed with %llu/%llx, (unsigned long long):
>
> @@ -32,4 +146,5 @@ Reminder: sizeof() result is of type size_t.
> Thank you for your cooperation and attention.
>
>
> -By Randy Dunlap <[email protected]>
> +By Randy Dunlap <[email protected]> and
> +Andrew Murray <[email protected]>
> --
> 1.7.4.1
>

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

2011-06-09 21:25:01

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

From: Andrew Murray <[email protected]>

This patch updates the incomplete documentation concerning the printk
extended format specifiers

Signed-off-by: Andrew Murray <[email protected]>
---
Documentation/printk-formats.txt | 119 +++++++++++++++++++++++++++++++++++++-
1 files changed, 117 insertions(+), 2 deletions(-)

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 1b5a5dd..6455e5b 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -9,7 +9,121 @@ If variable is of Type, use printk format specifier:
size_t %zu or %zx
ssize_t %zd or %zx

-Raw pointer value SHOULD be printed with %p.
+Raw pointer value SHOULD be printed with %p. The kernel supports
+the following extended format specifiers for pointer types:
+
+Symbols/Function Pointers:
+
+ %pF versatile_init+0x0/0x110
+ %pf versatile_init
+ %pS versatile_init+0x0/0x110
+ %ps versatile_init
+ %pB prev_fn_of_versatile_init+0x88/0x88
+
+ For printing symbols and function pointers. The 'S' and 's' specifiers
+ result in the symbol name with ('S') or without ('s') offsets. Where
+ this is used on a kernel without KALLSYMS - the symbol address is
+ printed instead.
+
+ The 'B' specifier results in the symbol name with offsets and should be
+ used when printing stack backtraces. The specifier takes into
+ consideration the effect of compiler optimisations which may occur
+ when tail-call's are used and marked with the noreturn GCC attribute.
+
+ On ia64, ppc64 and parisc64 architectures function pointers are
+ actually function descriptors which must first be resolved. The 'F' and
+ 'f' specifiers perform this resolution and then provide the same
+ functionality as the 'S' and 's' specifiers.
+
+Kernel Pointers:
+
+ %pK 0x01234567 or 0x0123456789abcdef
+
+ For printing kernel pointers which should be hidden from unprivileged
+ users. The behaviour of %pK depends on the kptr_restrict sysctl - see
+ Documentation/sysctl/kernel.txt for more details.
+
+Struct Resources:
+
+ %pr [mem 0x60000000-0x6fffffff flags 0x2200] or
+ [mem 0x0000000060000000-0x000000006fffffff flags 0x2200]
+ %pR [mem 0x60000000-0x6fffffff pref] or
+ [mem 0x0000000060000000-0x000000006fffffff pref]
+
+ For printing struct resources. The 'R' and 'r' specifiers result in a
+ printed resource with ('R') or without ('r') a decoded flags member.
+
+MAC/FDDI addresses:
+
+ %pM 00:01:02:03:04:05
+ %pMF 00-01-02-03-04-05
+ %pm 000102030405
+
+ For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
+ specifiers result in a printed address with ('M') or without ('m') byte
+ separators. The default byte separator is the colon (':').
+
+ Where FDDI addresses are concerned the 'F' specifier can be used after
+ the 'M' specifier to use dash ('-') separators instead of the default
+ separator.
+
+IPv4 addresses:
+
+ %pI4 1.2.3.4
+ %pi4 001.002.003.004
+ %p[Ii][hnbl]
+
+ For printing IPv4 dot-separated decimal addresses. The 'I4' and 'i4'
+ specifiers result in a printed address with ('i4') or without ('I4')
+ leading zeros.
+
+ The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
+ host, network, big or little endian order addresses respectively. Where
+ no specifier is provided the default network/big endian order is used.
+
+IPv6 addresses:
+
+ %pI6 0001:0002:0003:0004:0005:0006:0007:0008
+ %pi6 00010002000300040005000600070008
+ %pI6c 1:2:3:4:5:6:7:8
+
+ For printing IPv6 network-order 16-bit hex addresses. The 'I6' and 'i6'
+ specifiers result in a printed address with ('I6') or without ('i6')
+ colon-separators. Leading zeros are always used.
+
+ The additional 'c' specifier can be used with the 'I' specifier to
+ print a compressed IPv6 address as described by
+ http://tools.ietf.org/html/rfc5952
+
+UUID/GUID addresses:
+
+ %pUb 00010203-0405-0607-0809-0a0b0c0d0e0f
+ %pUB 00010203-0405-0607-0809-0A0B0C0D0E0F
+ %pUl 03020100-0504-0706-0809-0a0b0c0e0e0f
+ %pUL 03020100-0504-0706-0809-0A0B0C0E0E0F
+
+ For printing-16 byte UUID/GUIDs addresses. The additional 'l', 'L',
+ 'b' and 'B' specifiers are used to specify a little endian order in
+ lower ('l') or upper case ('L') hex characters - and big endian order
+ in lower ('b') or upper case ('B') hex characters.
+
+ Where no additional specifiers are used the default little endian
+ order with lower case hex characters will be printed.
+
+struct va_format:
+
+ %pV
+
+ For printing struct va_format structures. These contain a format string
+ and va_list as follows:
+
+ struct va_format {
+ const char *fmt;
+ va_list *va;
+ };
+
+ Do not use this feature without some mechanism to verify the
+ correctness of the format string and va_list arguments.

u64 SHOULD be printed with %llu/%llx, (unsigned long long):

@@ -32,4 +146,5 @@ Reminder: sizeof() result is of type size_t.
Thank you for your cooperation and attention.

-By Randy Dunlap <[email protected]>
+By Randy Dunlap <[email protected]> and
+Andrew Murray <[email protected]>
--
1.7.4.1

2011-06-09 21:51:35

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

On Thu, 9 Jun 2011 22:24:48 +0100 Andrew Murray wrote:

> From: Andrew Murray <[email protected]>
>
> This patch updates the incomplete documentation concerning the printk
> extended format specifiers
>
> Signed-off-by: Andrew Murray <[email protected]>
> ---
> Documentation/printk-formats.txt | 119 +++++++++++++++++++++++++++++++++++++-
> 1 files changed, 117 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
> index 1b5a5dd..6455e5b 100644
> --- a/Documentation/printk-formats.txt
> +++ b/Documentation/printk-formats.txt
> @@ -9,7 +9,121 @@ If variable is of Type, use printk format specifier:

> +UUID/GUID addresses:
> +
> + %pUb 00010203-0405-0607-0809-0a0b0c0d0e0f
> + %pUB 00010203-0405-0607-0809-0A0B0C0D0E0F
> + %pUl 03020100-0504-0706-0809-0a0b0c0e0e0f
> + %pUL 03020100-0504-0706-0809-0A0B0C0E0E0F
> +
> + For printing-16 byte UUID/GUIDs addresses. The additional 'l', 'L',

For printing 16-byte

You want to resend or shall I just fix it?

> + 'b' and 'B' specifiers are used to specify a little endian order in
> + lower ('l') or upper case ('L') hex characters - and big endian order
> + in lower ('b') or upper case ('B') hex characters.
> +
> + Where no additional specifiers are used the default little endian
> + order with lower case hex characters will be printed.

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

2011-06-09 22:00:36

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

On Thu, 2011-06-09 at 14:51 -0700, Randy Dunlap wrote:
> On Thu, 9 Jun 2011 22:24:48 +0100 Andrew Murray wrote:
> > + For printing-16 byte UUID/GUIDs addresses. The additional 'l', 'L',
> For printing 16-byte
> You want to resend or shall I just fix it?

Hey Randy.

I find your seeming insistence on using a dash
between the numeric count and the word byte to
be a bit odd.

Stylistically, why do you want it there?

cheers, Joe

2011-06-09 22:21:10

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

On 9 June 2011 23:00, Joe Perches <[email protected]> wrote:
> On Thu, 2011-06-09 at 14:51 -0700, Randy Dunlap wrote:
>> On Thu, 9 Jun 2011 22:24:48 +0100 Andrew Murray wrote:
>> > + For printing-16 byte UUID/GUIDs addresses. The additional 'l', 'L',
>> For printing 16-byte
>> You want to resend or shall I just fix it?

Yes Randy please fix it - may be quicker for us both!

>
> Hey Randy.
>
> I find your seeming insistence on using a dash
> between the numeric count and the word byte to
> be a bit odd.
>
> Stylistically, why do you want it there?
>
> cheers, Joe
>
>

2011-06-09 22:44:26

[permalink] [raw]

Subject: Re: [PATCH] printk-formats.txt documentation update

On Thu, 09 Jun 2011 15:00:29 -0700 Joe Perches wrote:

> On Thu, 2011-06-09 at 14:51 -0700, Randy Dunlap wrote:
> > On Thu, 9 Jun 2011 22:24:48 +0100 Andrew Murray wrote:
> > > + For printing-16 byte UUID/GUIDs addresses. The additional 'l', 'L',
> > For printing 16-byte
> > You want to resend or shall I just fix it?
>
> Hey Randy.
>
> I find your seeming insistence on using a dash
> between the numeric count and the word byte to
> be a bit odd.
>
> Stylistically, why do you want it there?

Mostly to make it clear. It's too easy to be ambiguous.

> cheers, Joe

Without hyphen:

For printing 16 byte UUID/GUIDs addresses.

Those adjectives are confusing. I don't know what that phrase means.
It could easily mean 16 UUID/GUIDs, but it's ambiguous.

But

For printing 16-byte UUID/GUIDs addresses.

That means (clearly to me) that UUID/GUIDs are 16-byte entities.

Or see http://www.incredibleenglish.com/pdf/Hyphens.pdf, section 1,
"Hyphenate unit modifiers."

Or see http://www.ehow.com/how_4473498_use-hyphen-sentence.html, section 1,
"Link compound modifiers with hyphens."

Or see http://www.getitwriteonline.com/archive/040201HyphAdj.htm

HTH.
---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

2011-06-09 22:53:51

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Subject: Re: [PATCH] printk-formats.txt documentation update

On Thu, 2011-06-09 at 15:37 -0700, Randy Dunlap wrote:
> On Thu, 09 Jun 2011 15:00:29 -0700 Joe Perches wrote:
> see http://www.incredibleenglish.com/pdf/Hyphens.pdf, section 1,
> "Hyphenate unit modifiers."
>
> Or see http://www.ehow.com/how_4473498_use-hyphen-sentence.html, section 1,
> "Link compound modifiers with hyphens."
>
> Or see http://www.getitwriteonline.com/archive/040201HyphAdj.htm

Whatever floats your boat but my 5th grade English teacher
Sr. Mary likely would have been appalled by those articles.

cheers, Joe

2011-06-09 22:57:28

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Subject: Re: [PATCH] printk-formats.txt documentation update

On Thu, 09 Jun 2011 15:53:38 -0700 Joe Perches wrote:

> On Thu, 2011-06-09 at 15:37 -0700, Randy Dunlap wrote:
> > On Thu, 09 Jun 2011 15:00:29 -0700 Joe Perches wrote:
> > see http://www.incredibleenglish.com/pdf/Hyphens.pdf, section 1,
> > "Hyphenate unit modifiers."
> >
> > Or see http://www.ehow.com/how_4473498_use-hyphen-sentence.html, section 1,
> > "Link compound modifiers with hyphens."
> >
> > Or see http://www.getitwriteonline.com/archive/040201HyphAdj.htm
>
> Whatever floats your boat but my 5th grade English teacher
> Sr. Mary likely would have been appalled by those articles.
>
> cheers, Joe

Thanks.

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

2011-06-10 17:50:21

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Subject: Re: [PATCH] printk-formats.txt documentation update

On Thu, 9 Jun 2011 22:24:48 +0100 Andrew Murray wrote:

> From: Andrew Murray <[email protected]>
>
> This patch updates the incomplete documentation concerning the printk
> extended format specifiers
>
> Signed-off-by: Andrew Murray <[email protected]>

Applied with minor tweaks (including dropping trailing whitespace).

Thanks.

> ---
> Documentation/printk-formats.txt | 119 +++++++++++++++++++++++++++++++++++++-
> 1 files changed, 117 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
> index 1b5a5dd..6455e5b 100644
> --- a/Documentation/printk-formats.txt
> +++ b/Documentation/printk-formats.txt
> @@ -9,7 +9,121 @@ If variable is of Type, use printk format specifier:
> size_t %zu or %zx
> ssize_t %zd or %zx
>
> -Raw pointer value SHOULD be printed with %p.
> +Raw pointer value SHOULD be printed with %p. The kernel supports
> +the following extended format specifiers for pointer types:
> +
> +Symbols/Function Pointers:
> +
> + %pF versatile_init+0x0/0x110
> + %pf versatile_init
> + %pS versatile_init+0x0/0x110
> + %ps versatile_init
> + %pB prev_fn_of_versatile_init+0x88/0x88
> +
> + For printing symbols and function pointers. The 'S' and 's' specifiers
> + result in the symbol name with ('S') or without ('s') offsets. Where
> + this is used on a kernel without KALLSYMS - the symbol address is
> + printed instead.
> +
> + The 'B' specifier results in the symbol name with offsets and should be
> + used when printing stack backtraces. The specifier takes into
> + consideration the effect of compiler optimisations which may occur
> + when tail-call's are used and marked with the noreturn GCC attribute.
> +
> + On ia64, ppc64 and parisc64 architectures function pointers are
> + actually function descriptors which must first be resolved. The 'F' and
> + 'f' specifiers perform this resolution and then provide the same
> + functionality as the 'S' and 's' specifiers.
> +
> +Kernel Pointers:
> +
> + %pK 0x01234567 or 0x0123456789abcdef
> +
> + For printing kernel pointers which should be hidden from unprivileged
> + users. The behaviour of %pK depends on the kptr_restrict sysctl - see
> + Documentation/sysctl/kernel.txt for more details.
> +
> +Struct Resources:
> +
> + %pr [mem 0x60000000-0x6fffffff flags 0x2200] or
> + [mem 0x0000000060000000-0x000000006fffffff flags 0x2200]
> + %pR [mem 0x60000000-0x6fffffff pref] or
> + [mem 0x0000000060000000-0x000000006fffffff pref]
> +
> + For printing struct resources. The 'R' and 'r' specifiers result in a
> + printed resource with ('R') or without ('r') a decoded flags member.
> +
> +MAC/FDDI addresses:
> +
> + %pM 00:01:02:03:04:05
> + %pMF 00-01-02-03-04-05
> + %pm 000102030405
> +
> + For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
> + specifiers result in a printed address with ('M') or without ('m') byte
> + separators. The default byte separator is the colon (':').
> +
> + Where FDDI addresses are concerned the 'F' specifier can be used after
> + the 'M' specifier to use dash ('-') separators instead of the default
> + separator.
> +
> +IPv4 addresses:
> +
> + %pI4 1.2.3.4
> + %pi4 001.002.003.004
> + %p[Ii][hnbl]
> +
> + For printing IPv4 dot-separated decimal addresses. The 'I4' and 'i4'
> + specifiers result in a printed address with ('i4') or without ('I4')
> + leading zeros.
> +
> + The additional 'h', 'n', 'b', and 'l' specifiers are used to specify
> + host, network, big or little endian order addresses respectively. Where
> + no specifier is provided the default network/big endian order is used.
> +
> +IPv6 addresses:
> +
> + %pI6 0001:0002:0003:0004:0005:0006:0007:0008
> + %pi6 00010002000300040005000600070008
> + %pI6c 1:2:3:4:5:6:7:8
> +
> + For printing IPv6 network-order 16-bit hex addresses. The 'I6' and 'i6'
> + specifiers result in a printed address with ('I6') or without ('i6')
> + colon-separators. Leading zeros are always used.
> +
> + The additional 'c' specifier can be used with the 'I' specifier to
> + print a compressed IPv6 address as described by
> + http://tools.ietf.org/html/rfc5952
> +
> +UUID/GUID addresses:
> +
> + %pUb 00010203-0405-0607-0809-0a0b0c0d0e0f
> + %pUB 00010203-0405-0607-0809-0A0B0C0D0E0F
> + %pUl 03020100-0504-0706-0809-0a0b0c0e0e0f
> + %pUL 03020100-0504-0706-0809-0A0B0C0E0E0F
> +
> + For printing-16 byte UUID/GUIDs addresses. The additional 'l', 'L',
> + 'b' and 'B' specifiers are used to specify a little endian order in
> + lower ('l') or upper case ('L') hex characters - and big endian order
> + in lower ('b') or upper case ('B') hex characters.
> +
> + Where no additional specifiers are used the default little endian
> + order with lower case hex characters will be printed.
> +
> +struct va_format:
> +
> + %pV
> +
> + For printing struct va_format structures. These contain a format string
> + and va_list as follows:
> +
> + struct va_format {
> + const char *fmt;
> + va_list *va;
> + };
> +
> + Do not use this feature without some mechanism to verify the
> + correctness of the format string and va_list arguments.
>
> u64 SHOULD be printed with %llu/%llx, (unsigned long long):
>
> @@ -32,4 +146,5 @@ Reminder: sizeof() result is of type size_t.
> Thank you for your cooperation and attention.
>
>
> -By Randy Dunlap <[email protected]>
> +By Randy Dunlap <[email protected]> and
> +Andrew Murray <[email protected]>
> --
> 1.7.4.1
>
> --
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---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

2011-06-10 17:56:38