2017-03-30 13:03:14

by Fengguang Wu

[permalink] [raw]

Subject: [tip:x86/asm 3/3] lib/bug.c:135: undefined reference to `__start___bug_table'

---

tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/asm
head: 19d436268dde95389c616bb3819da73f0a8b28a8
commit: 19d436268dde95389c616bb3819da73f0a8b28a8 [3/3] debug: Add _ONCE() logic to report_bug()
config: arm-efm32_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
git checkout 19d436268dde95389c616bb3819da73f0a8b28a8
# save the attached .config to linux build tree
make.cross ARCH=arm

All errors (new ones prefixed by >>):

lib/lib.a(bug.o): In function `find_bug':
>> lib/bug.c:135: undefined reference to `__start___bug_table'
>> lib/bug.c:135: undefined reference to `__stop___bug_table'

vim +135 lib/bug.c

7664c5a1 Jeremy Fitzhardinge 2006-12-08 129 #endif
7664c5a1 Jeremy Fitzhardinge 2006-12-08 130
19d43626 Peter Zijlstra 2017-02-25 131 struct bug_entry *find_bug(unsigned long bugaddr)
7664c5a1 Jeremy Fitzhardinge 2006-12-08 132 {
19d43626 Peter Zijlstra 2017-02-25 133 struct bug_entry *bug;
7664c5a1 Jeremy Fitzhardinge 2006-12-08 134
7664c5a1 Jeremy Fitzhardinge 2006-12-08 @135 for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
b93a531e Jan Beulich 2008-12-16 136 if (bugaddr == bug_addr(bug))
7664c5a1 Jeremy Fitzhardinge 2006-12-08 137 return bug;
7664c5a1 Jeremy Fitzhardinge 2006-12-08 138

:::::: The code at line 135 was first introduced by commit
:::::: 7664c5a1da4711bb6383117f51b94c8dc8f3f1cd [PATCH] Generic BUG implementation

:::::: TO: Jeremy Fitzhardinge <[email protected]>
:::::: CC: Linus Torvalds <[email protected]>

---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation

---

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2017-03-30 15:49:34

by Peter Zijlstra

[permalink] [raw]

Subject: Re: [tip:x86/asm 3/3] lib/bug.c:135: undefined reference to `__start___bug_table'

---

On Thu, Mar 30, 2017 at 09:02:31PM +0800, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/asm
> head: 19d436268dde95389c616bb3819da73f0a8b28a8
> commit: 19d436268dde95389c616bb3819da73f0a8b28a8 [3/3] debug: Add _ONCE() logic to report_bug()
> config: arm-efm32_defconfig (attached as .config)
> compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
> reproduce:
> wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> git checkout 19d436268dde95389c616bb3819da73f0a8b28a8
> # save the attached .config to linux build tree
> make.cross ARCH=arm
>
> All errors (new ones prefixed by >>):
>
> lib/lib.a(bug.o): In function `find_bug':
> >> lib/bug.c:135: undefined reference to `__start___bug_table'
> >> lib/bug.c:135: undefined reference to `__stop___bug_table'

Blergh.. this cures it for me.

Ideally all those would use RW_DATA_SECTION, but alas.

---
arch/arm/kernel/vmlinux-xip.lds.S | 2 ++
arch/arm/kernel/vmlinux.lds.S | 2 ++
arch/avr32/kernel/vmlinux.lds.S | 1 +
arch/blackfin/kernel/vmlinux.lds.S | 2 ++
arch/c6x/kernel/vmlinux.lds.S | 2 ++
arch/cris/kernel/vmlinux.lds.S | 2 ++
arch/frv/kernel/vmlinux.lds.S | 2 ++
arch/ia64/kernel/vmlinux.lds.S | 2 ++
arch/mips/kernel/vmlinux.lds.S | 1 +
arch/powerpc/kernel/vmlinux.lds.S | 2 ++
arch/x86/kernel/vmlinux.lds.S | 1 +
11 files changed, 19 insertions(+)

diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
index 37b2a11..8265b11 100644
--- a/arch/arm/kernel/vmlinux-xip.lds.S
+++ b/arch/arm/kernel/vmlinux-xip.lds.S
@@ -242,6 +242,8 @@ SECTIONS
}
_edata_loc = __data_loc + SIZEOF(.data);

+ BUG_TABLE
+
#ifdef CONFIG_HAVE_TCM
/*
* We align everything to a page boundary so we can
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index ce18007..c83a7ba 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -262,6 +262,8 @@ SECTIONS
}
_edata_loc = __data_loc + SIZEOF(.data);

+ BUG_TABLE
+
#ifdef CONFIG_HAVE_TCM
/*
* We align everything to a page boundary so we can
diff --git a/arch/avr32/kernel/vmlinux.lds.S b/arch/avr32/kernel/vmlinux.lds.S
index 17f2730..623d18d 100644
--- a/arch/avr32/kernel/vmlinux.lds.S
+++ b/arch/avr32/kernel/vmlinux.lds.S
@@ -75,6 +75,7 @@ SECTIONS

_edata = .;
}
+ BUG_TABLE

BSS_SECTION(0, 8, 8)
_end = .;
diff --git a/arch/blackfin/kernel/vmlinux.lds.S b/arch/blackfin/kernel/vmlinux.lds.S
index 68069a1..334ef81 100644
--- a/arch/blackfin/kernel/vmlinux.lds.S
+++ b/arch/blackfin/kernel/vmlinux.lds.S
@@ -115,6 +115,8 @@ SECTIONS
__data_lma = LOADADDR(.data);
__data_len = SIZEOF(.data);

+ BUG_TABLE
+
/* The init section should be last, so when we free it, it goes into
* the general memory pool, and (hopefully) will decrease fragmentation
* a tiny bit. The init section has a _requirement_ that it be
diff --git a/arch/c6x/kernel/vmlinux.lds.S b/arch/c6x/kernel/vmlinux.lds.S
index a1a5c16..29ebea4 100644
--- a/arch/c6x/kernel/vmlinux.lds.S
+++ b/arch/c6x/kernel/vmlinux.lds.S
@@ -128,6 +128,8 @@ SECTIONS
. = ALIGN(8);
}

+ BUG_TABLE
+
_edata = .;

__bss_start = .;
diff --git a/arch/cris/kernel/vmlinux.lds.S b/arch/cris/kernel/vmlinux.lds.S
index 9795862..867f237 100644
--- a/arch/cris/kernel/vmlinux.lds.S
+++ b/arch/cris/kernel/vmlinux.lds.S
@@ -68,6 +68,8 @@ SECTIONS
__edata = . ; /* End of data section. */
_edata = . ;

+ BUG_TABLE
+
INIT_TASK_DATA_SECTION(PAGE_SIZE)

. = ALIGN(PAGE_SIZE); /* Init code and data. */
diff --git a/arch/frv/kernel/vmlinux.lds.S b/arch/frv/kernel/vmlinux.lds.S
index aa6e573..3f44dcb 100644
--- a/arch/frv/kernel/vmlinux.lds.S
+++ b/arch/frv/kernel/vmlinux.lds.S
@@ -102,6 +102,8 @@ SECTIONS

_edata = .; /* End of data section */

+ BUG_TABLE
+
/* GP section */
. = ALIGN(L1_CACHE_BYTES);
_gp = . + 2048;
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index f89d20c..798026d 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -192,6 +192,8 @@ SECTIONS {
CONSTRUCTORS
}

+ BUG_TABLE
+
. = ALIGN(16); /* gp must be 16-byte aligned for exc. table */
.got : AT(ADDR(.got) - LOAD_OFFSET) {
*(.got.plt)
diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index f0a0e6d..8ca2371 100644
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -97,6 +97,7 @@ SECTIONS
DATA_DATA
CONSTRUCTORS
}
+ BUG_TABLE
_gp = . + 0x8000;
.lit8 : {
*(.lit8)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 7394b77..1c24c89 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -312,6 +312,8 @@ SECTIONS
NOSAVE_DATA
}

+ BUG_TABLE
+
. = ALIGN(PAGE_SIZE);
_edata = .;
PROVIDE32 (edata = .);
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index c74ae9c..c8a3b61 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -146,6 +146,7 @@ SECTIONS
_edata = .;
} :data

+ BUG_TABLE

. = ALIGN(PAGE_SIZE);
__vvar_page = .;

2017-03-30 15:53:33

by Peter Zijlstra

[permalink] [raw]

Subject: Re: [tip:x86/asm 3/3] lib/bug.c:135: undefined reference to `__start___bug_table'

---

On Thu, Mar 30, 2017 at 05:49:27PM +0200, Peter Zijlstra wrote:
> On Thu, Mar 30, 2017 at 09:02:31PM +0800, kbuild test robot wrote:
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/asm
> > head: 19d436268dde95389c616bb3819da73f0a8b28a8
> > commit: 19d436268dde95389c616bb3819da73f0a8b28a8 [3/3] debug: Add _ONCE() logic to report_bug()
> > config: arm-efm32_defconfig (attached as .config)
> > compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
> > reproduce:
> > wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > chmod +x ~/bin/make.cross
> > git checkout 19d436268dde95389c616bb3819da73f0a8b28a8
> > # save the attached .config to linux build tree
> > make.cross ARCH=arm
> >
> > All errors (new ones prefixed by >>):
> >
> > lib/lib.a(bug.o): In function `find_bug':
> > >> lib/bug.c:135: undefined reference to `__start___bug_table'
> > >> lib/bug.c:135: undefined reference to `__stop___bug_table'
>
> Blergh.. this cures it for me.
>
> Ideally all those would use RW_DATA_SECTION, but alas.
>

> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
> index c74ae9c..c8a3b61 100644
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -146,6 +146,7 @@ SECTIONS
> _edata = .;
> } :data
>
> + BUG_TABLE
>
> . = ALIGN(PAGE_SIZE);
> __vvar_page = .;

Also, I have absolutely 0 clues as to why x86 builds without this :/

2017-03-31 00:27:33

by Fengguang Wu

[permalink] [raw]

Subject: Re: [tip:x86/asm 3/3] lib/bug.c:135: undefined reference to `__start___bug_table'

---

On Thu, Mar 30, 2017 at 05:53:27PM +0200, Peter Zijlstra wrote:
>On Thu, Mar 30, 2017 at 05:49:27PM +0200, Peter Zijlstra wrote:
>> On Thu, Mar 30, 2017 at 09:02:31PM +0800, kbuild test robot wrote:
>> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/asm
>> > head: 19d436268dde95389c616bb3819da73f0a8b28a8
>> > commit: 19d436268dde95389c616bb3819da73f0a8b28a8 [3/3] debug: Add _ONCE() logic to report_bug()
>> > config: arm-efm32_defconfig (attached as .config)
>> > compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
>> > reproduce:
>> > wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>> > chmod +x ~/bin/make.cross
>> > git checkout 19d436268dde95389c616bb3819da73f0a8b28a8
>> > # save the attached .config to linux build tree
>> > make.cross ARCH=arm
>> >
>> > All errors (new ones prefixed by >>):
>> >
>> > lib/lib.a(bug.o): In function `find_bug':
>> > >> lib/bug.c:135: undefined reference to `__start___bug_table'
>> > >> lib/bug.c:135: undefined reference to `__stop___bug_table'
>>
>> Blergh.. this cures it for me.
>>
>> Ideally all those would use RW_DATA_SECTION, but alas.
>>
>
>> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
>> index c74ae9c..c8a3b61 100644
>> --- a/arch/x86/kernel/vmlinux.lds.S
>> +++ b/arch/x86/kernel/vmlinux.lds.S
>> @@ -146,6 +146,7 @@ SECTIONS
>> _edata = .;
>> } :data
>>
>> + BUG_TABLE
>>
>> . = ALIGN(PAGE_SIZE);
>> __vvar_page = .;
>
>Also, I have absolutely 0 clues as to why x86 builds without this :/

Yes there are no x86 build failures with this error message.
It only occurs in arm and c6x.

Regards,
Fengguang

2017-04-03 08:31:33

by tip-bot for Vasyl Gomonovych

[permalink] [raw]

Subject: [tip:x86/asm] debug: Fix __bug_table[] in arch linker scripts

---

Commit-ID: b5effd3815ccbe3df1a015a6d67d8a24a27813d5
Gitweb: http://git.kernel.org/tip/b5effd3815ccbe3df1a015a6d67d8a24a27813d5
Author: Peter Zijlstra <[email protected]>
AuthorDate: Thu, 30 Mar 2017 17:49:27 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Mon, 3 Apr 2017 10:22:40 +0200

debug: Fix __bug_table[] in arch linker scripts

The kbuild test robot reported this build failure on a number
of architectures:

> make.cross ARCH=arm
> lib/lib.a(bug.o): In function `find_bug':
> >> lib/bug.c:135: undefined reference to `__start___bug_table'
> >> lib/bug.c:135: undefined reference to `__stop___bug_table'

Caused by:

19d436268dde ("debug: Add _ONCE() logic to report_bug()")

Which moved the BUG_TABLE from RO_DATA_SECTION() to RW_DATA_SECTION(),
but a number of architectures don't use RW_DATA_SECTION(), so they
ended up with no __bug_table[] ...

Ideally all those would use RW_DATA_SECTION() in their linker scripts,
but that's for another day.

Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: kbuild test robot <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/arm/kernel/vmlinux-xip.lds.S | 2 ++
arch/arm/kernel/vmlinux.lds.S | 2 ++
arch/avr32/kernel/vmlinux.lds.S | 1 +
arch/blackfin/kernel/vmlinux.lds.S | 2 ++
arch/c6x/kernel/vmlinux.lds.S | 2 ++
arch/cris/kernel/vmlinux.lds.S | 2 ++
arch/frv/kernel/vmlinux.lds.S | 2 ++
arch/ia64/kernel/vmlinux.lds.S | 2 ++
arch/mips/kernel/vmlinux.lds.S | 1 +
arch/powerpc/kernel/vmlinux.lds.S | 2 ++
arch/x86/kernel/vmlinux.lds.S | 1 +
11 files changed, 19 insertions(+)

diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
index 37b2a11..8265b11 100644
--- a/arch/arm/kernel/vmlinux-xip.lds.S
+++ b/arch/arm/kernel/vmlinux-xip.lds.S
@@ -242,6 +242,8 @@ SECTIONS
}
_edata_loc = __data_loc + SIZEOF(.data);

+ BUG_TABLE
+
#ifdef CONFIG_HAVE_TCM
/*
* We align everything to a page boundary so we can
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index ce18007..c83a7ba 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -262,6 +262,8 @@ SECTIONS
}
_edata_loc = __data_loc + SIZEOF(.data);

+ BUG_TABLE
+
#ifdef CONFIG_HAVE_TCM
/*
* We align everything to a page boundary so we can
diff --git a/arch/avr32/kernel/vmlinux.lds.S b/arch/avr32/kernel/vmlinux.lds.S
index 17f2730..623d18d 100644
--- a/arch/avr32/kernel/vmlinux.lds.S
+++ b/arch/avr32/kernel/vmlinux.lds.S
@@ -75,6 +75,7 @@ SECTIONS

_edata = .;
}
+ BUG_TABLE

BSS_SECTION(0, 8, 8)
_end = .;
diff --git a/arch/blackfin/kernel/vmlinux.lds.S b/arch/blackfin/kernel/vmlinux.lds.S
index 68069a1..334ef81 100644
--- a/arch/blackfin/kernel/vmlinux.lds.S
+++ b/arch/blackfin/kernel/vmlinux.lds.S
@@ -115,6 +115,8 @@ SECTIONS
__data_lma = LOADADDR(.data);
__data_len = SIZEOF(.data);

+ BUG_TABLE
+
/* The init section should be last, so when we free it, it goes into
* the general memory pool, and (hopefully) will decrease fragmentation
* a tiny bit. The init section has a _requirement_ that it be
diff --git a/arch/c6x/kernel/vmlinux.lds.S b/arch/c6x/kernel/vmlinux.lds.S
index a1a5c16..29ebea4 100644
--- a/arch/c6x/kernel/vmlinux.lds.S
+++ b/arch/c6x/kernel/vmlinux.lds.S
@@ -128,6 +128,8 @@ SECTIONS
. = ALIGN(8);
}

+ BUG_TABLE
+
_edata = .;

__bss_start = .;
diff --git a/arch/cris/kernel/vmlinux.lds.S b/arch/cris/kernel/vmlinux.lds.S
index 9795862..867f237 100644
--- a/arch/cris/kernel/vmlinux.lds.S
+++ b/arch/cris/kernel/vmlinux.lds.S
@@ -68,6 +68,8 @@ SECTIONS
__edata = . ; /* End of data section. */
_edata = . ;

+ BUG_TABLE
+
INIT_TASK_DATA_SECTION(PAGE_SIZE)

. = ALIGN(PAGE_SIZE); /* Init code and data. */
diff --git a/arch/frv/kernel/vmlinux.lds.S b/arch/frv/kernel/vmlinux.lds.S
index aa6e573..3f44dcb 100644
--- a/arch/frv/kernel/vmlinux.lds.S
+++ b/arch/frv/kernel/vmlinux.lds.S
@@ -102,6 +102,8 @@ SECTIONS

_edata = .; /* End of data section */

+ BUG_TABLE
+
/* GP section */
. = ALIGN(L1_CACHE_BYTES);
_gp = . + 2048;
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index f89d20c..798026d 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -192,6 +192,8 @@ SECTIONS {
CONSTRUCTORS
}

+ BUG_TABLE
+
. = ALIGN(16); /* gp must be 16-byte aligned for exc. table */
.got : AT(ADDR(.got) - LOAD_OFFSET) {
*(.got.plt)
diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index f0a0e6d..8ca2371 100644
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -97,6 +97,7 @@ SECTIONS
DATA_DATA
CONSTRUCTORS
}
+ BUG_TABLE
_gp = . + 0x8000;
.lit8 : {
*(.lit8)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 7394b77..1c24c89 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -312,6 +312,8 @@ SECTIONS
NOSAVE_DATA
}

+ BUG_TABLE
+
. = ALIGN(PAGE_SIZE);
_edata = .;
PROVIDE32 (edata = .);
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index c74ae9c..c8a3b61 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -146,6 +146,7 @@ SECTIONS
_edata = .;
} :data

+ BUG_TABLE

. = ALIGN(PAGE_SIZE);
__vvar_page = .;

2017-04-03 10:05:49

by H. Peter Anvin

[permalink] [raw]

Subject: Re: [tip:x86/asm] debug: Fix __bug_table[] in arch linker scripts

---

On April 3, 2017 1:27:49 AM PDT, tip-bot for Peter Zijlstra <[email protected]> wrote:
>Commit-ID: b5effd3815ccbe3df1a015a6d67d8a24a27813d5
>Gitweb:
>http://git.kernel.org/tip/b5effd3815ccbe3df1a015a6d67d8a24a27813d5
>Author: Peter Zijlstra <[email protected]>
>AuthorDate: Thu, 30 Mar 2017 17:49:27 +0200
>Committer: Ingo Molnar <[email protected]>
>CommitDate: Mon, 3 Apr 2017 10:22:40 +0200
>
>debug: Fix __bug_table[] in arch linker scripts
>
>The kbuild test robot reported this build failure on a number
>of architectures:
>
> > make.cross ARCH=arm
> > lib/lib.a(bug.o): In function `find_bug':
> > >> lib/bug.c:135: undefined reference to `__start___bug_table'
> > >> lib/bug.c:135: undefined reference to `__stop___bug_table'
>
>Caused by:
>
> 19d436268dde ("debug: Add _ONCE() logic to report_bug()")
>
>Which moved the BUG_TABLE from RO_DATA_SECTION() to RW_DATA_SECTION(),
>but a number of architectures don't use RW_DATA_SECTION(), so they
>ended up with no __bug_table[] ...
>
>Ideally all those would use RW_DATA_SECTION() in their linker scripts,
>but that's for another day.
>
>Signed-off-by: Peter Zijlstra <[email protected]>
>Cc: Linus Torvalds <[email protected]>
>Cc: Thomas Gleixner <[email protected]>
>Cc: kbuild test robot <[email protected]>
>Cc: [email protected]
>Cc: [email protected]
>Link:
>http://lkml.kernel.org/r/[email protected]
>Signed-off-by: Ingo Molnar <[email protected]>
>---
> arch/arm/kernel/vmlinux-xip.lds.S | 2 ++
> arch/arm/kernel/vmlinux.lds.S | 2 ++
> arch/avr32/kernel/vmlinux.lds.S | 1 +
> arch/blackfin/kernel/vmlinux.lds.S | 2 ++
> arch/c6x/kernel/vmlinux.lds.S | 2 ++
> arch/cris/kernel/vmlinux.lds.S | 2 ++
> arch/frv/kernel/vmlinux.lds.S | 2 ++
> arch/ia64/kernel/vmlinux.lds.S | 2 ++
> arch/mips/kernel/vmlinux.lds.S | 1 +
> arch/powerpc/kernel/vmlinux.lds.S | 2 ++
> arch/x86/kernel/vmlinux.lds.S | 1 +
> 11 files changed, 19 insertions(+)
>
>diff --git a/arch/arm/kernel/vmlinux-xip.lds.S
>b/arch/arm/kernel/vmlinux-xip.lds.S
>index 37b2a11..8265b11 100644
>--- a/arch/arm/kernel/vmlinux-xip.lds.S
>+++ b/arch/arm/kernel/vmlinux-xip.lds.S
>@@ -242,6 +242,8 @@ SECTIONS
> }
> _edata_loc = __data_loc + SIZEOF(.data);
>
>+ BUG_TABLE
>+
> #ifdef CONFIG_HAVE_TCM
> /*
> * We align everything to a page boundary so we can
>diff --git a/arch/arm/kernel/vmlinux.lds.S
>b/arch/arm/kernel/vmlinux.lds.S
>index ce18007..c83a7ba 100644
>--- a/arch/arm/kernel/vmlinux.lds.S
>+++ b/arch/arm/kernel/vmlinux.lds.S
>@@ -262,6 +262,8 @@ SECTIONS
> }
> _edata_loc = __data_loc + SIZEOF(.data);
>
>+ BUG_TABLE
>+
> #ifdef CONFIG_HAVE_TCM
> /*
> * We align everything to a page boundary so we can
>diff --git a/arch/avr32/kernel/vmlinux.lds.S
>b/arch/avr32/kernel/vmlinux.lds.S
>index 17f2730..623d18d 100644
>--- a/arch/avr32/kernel/vmlinux.lds.S
>+++ b/arch/avr32/kernel/vmlinux.lds.S
>@@ -75,6 +75,7 @@ SECTIONS
>
> _edata = .;
> }
>+ BUG_TABLE
>
> BSS_SECTION(0, 8, 8)
> _end = .;
>diff --git a/arch/blackfin/kernel/vmlinux.lds.S
>b/arch/blackfin/kernel/vmlinux.lds.S
>index 68069a1..334ef81 100644
>--- a/arch/blackfin/kernel/vmlinux.lds.S
>+++ b/arch/blackfin/kernel/vmlinux.lds.S
>@@ -115,6 +115,8 @@ SECTIONS
> __data_lma = LOADADDR(.data);
> __data_len = SIZEOF(.data);
>
>+ BUG_TABLE
>+
> /* The init section should be last, so when we free it, it goes into
> * the general memory pool, and (hopefully) will decrease
>fragmentation
> * a tiny bit. The init section has a _requirement_ that it be
>diff --git a/arch/c6x/kernel/vmlinux.lds.S
>b/arch/c6x/kernel/vmlinux.lds.S
>index a1a5c16..29ebea4 100644
>--- a/arch/c6x/kernel/vmlinux.lds.S
>+++ b/arch/c6x/kernel/vmlinux.lds.S
>@@ -128,6 +128,8 @@ SECTIONS
> . = ALIGN(8);
> }
>
>+ BUG_TABLE
>+
> _edata = .;
>
> __bss_start = .;
>diff --git a/arch/cris/kernel/vmlinux.lds.S
>b/arch/cris/kernel/vmlinux.lds.S
>index 9795862..867f237 100644
>--- a/arch/cris/kernel/vmlinux.lds.S
>+++ b/arch/cris/kernel/vmlinux.lds.S
>@@ -68,6 +68,8 @@ SECTIONS
> __edata = . ; /* End of data section. */
> _edata = . ;
>
>+ BUG_TABLE
>+
> INIT_TASK_DATA_SECTION(PAGE_SIZE)
>
> . = ALIGN(PAGE_SIZE); /* Init code and data. */
>diff --git a/arch/frv/kernel/vmlinux.lds.S
>b/arch/frv/kernel/vmlinux.lds.S
>index aa6e573..3f44dcb 100644
>--- a/arch/frv/kernel/vmlinux.lds.S
>+++ b/arch/frv/kernel/vmlinux.lds.S
>@@ -102,6 +102,8 @@ SECTIONS
>
> _edata = .; /* End of data section */
>
>+ BUG_TABLE
>+
> /* GP section */
> . = ALIGN(L1_CACHE_BYTES);
> _gp = . + 2048;
>diff --git a/arch/ia64/kernel/vmlinux.lds.S
>b/arch/ia64/kernel/vmlinux.lds.S
>index f89d20c..798026d 100644
>--- a/arch/ia64/kernel/vmlinux.lds.S
>+++ b/arch/ia64/kernel/vmlinux.lds.S
>@@ -192,6 +192,8 @@ SECTIONS {
> CONSTRUCTORS
> }
>
>+ BUG_TABLE
>+
> . = ALIGN(16); /* gp must be 16-byte aligned for exc. table */
> .got : AT(ADDR(.got) - LOAD_OFFSET) {
> *(.got.plt)
>diff --git a/arch/mips/kernel/vmlinux.lds.S
>b/arch/mips/kernel/vmlinux.lds.S
>index f0a0e6d..8ca2371 100644
>--- a/arch/mips/kernel/vmlinux.lds.S
>+++ b/arch/mips/kernel/vmlinux.lds.S
>@@ -97,6 +97,7 @@ SECTIONS
> DATA_DATA
> CONSTRUCTORS
> }
>+ BUG_TABLE
> _gp = . + 0x8000;
> .lit8 : {
> *(.lit8)
>diff --git a/arch/powerpc/kernel/vmlinux.lds.S
>b/arch/powerpc/kernel/vmlinux.lds.S
>index 7394b77..1c24c89 100644
>--- a/arch/powerpc/kernel/vmlinux.lds.S
>+++ b/arch/powerpc/kernel/vmlinux.lds.S
>@@ -312,6 +312,8 @@ SECTIONS
> NOSAVE_DATA
> }
>
>+ BUG_TABLE
>+
> . = ALIGN(PAGE_SIZE);
> _edata = .;
> PROVIDE32 (edata = .);
>diff --git a/arch/x86/kernel/vmlinux.lds.S
>b/arch/x86/kernel/vmlinux.lds.S
>index c74ae9c..c8a3b61 100644
>--- a/arch/x86/kernel/vmlinux.lds.S
>+++ b/arch/x86/kernel/vmlinux.lds.S
>@@ -146,6 +146,7 @@ SECTIONS
> _edata = .;
> } :data
>
>+ BUG_TABLE
>
> . = ALIGN(PAGE_SIZE);
> __vvar_page = .;

Case in point why we want structured linker tables, btw...
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

2017-04-03 12:25:12

by Peter Zijlstra

[permalink] [raw]

Subject: Re: [tip:x86/asm] debug: Fix __bug_table[] in arch linker scripts

---

On Mon, Apr 03, 2017 at 02:57:48AM -0700, [email protected] wrote:
> On April 3, 2017 1:27:49 AM PDT, tip-bot for Peter Zijlstra <[email protected]> wrote:
> >diff --git a/arch/x86/kernel/vmlinux.lds.S
> >b/arch/x86/kernel/vmlinux.lds.S
> >index c74ae9c..c8a3b61 100644
> >--- a/arch/x86/kernel/vmlinux.lds.S
> >+++ b/arch/x86/kernel/vmlinux.lds.S
> >@@ -146,6 +146,7 @@ SECTIONS
> > _edata = .;
> > } :data
> >
> >+ BUG_TABLE
> >
> > . = ALIGN(PAGE_SIZE);
> > __vvar_page = .;
>
> Case in point why we want structured linker tables, btw...

Yes.

Btw, can you explain why x86 builds and works without this patch?
Because as far as I understand this (which isn't very far), we should
fail linking with an unresolved symbol without this.