2014-10-24 09:02:16

by Weijie Yang

[permalink] [raw]
Subject: [PATCH] x86, cma: reserve dma contiguous area after initmem_init()

Fengguang Wu reported a BUG: Int 6: CR2 (null) on x86 platform in
0-day Linux Kernel Performance Test:

[ 0.000000] BRK [0x025ee000, 0x025eefff] PGTABLE
[ 0.000000] cma: dma_contiguous_reserve(limit 13ffe000)
[ 0.000000] cma: dma_contiguous_reserve: reserving 31 MiB for global area
[ 0.000000] BUG: Int 6: CR2 (null)
[ 0.000000] EDI c0000000 ESI (null) EBP 41c11ea4 EBX 425cc101
[ 0.000000] ESP 41c11e98 ES 0000007b DS 0000007b
[ 0.000000] EDX 00000001 ECX (null) EAX 41cd8150
[ 0.000000] vec 00000006 err (null) EIP 41072227 CS 00000060 flg 00210002
[ 0.000000] Stack: 425cc150 (null) (null) 41c11ef4 41d4ee4d (null) 13ffe000 41c11ec4
[ 0.000000] 41c2d900 (null) 13ffe000 (null) 4185793e 0000002e 410c2982 41c11f00
[ 0.000000] 410c2df5 (null) (null) (null) 425cc150 00013efe (null) 41c11f28
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.17.0-next-20141008 #815
[ 0.000000] 00000000 425cc101 41c11e48 41850786 41c11ea4 41d2b1db 41d95f71 00000006
[ 0.000000] 00000000 c0000000 00000000 41c11ea4 425cc101 41c11e98 0000007b 0000007b
[ 0.000000] 00000001 00000000 41cd8150 00000006 00000000 41072227 00000060 00210002
[ 0.000000] Call Trace:
[ 0.000000] [<41850786>] dump_stack+0x16/0x18
[ 0.000000] [<41d2b1db>] early_idt_handler+0x6b/0x6b
[ 0.000000] [<41072227>] ? __phys_addr+0x2e/0xca
[ 0.000000] [<41d4ee4d>] cma_declare_contiguous+0x3c/0x2d7
[ 0.000000] [<4185793e>] ? _raw_spin_unlock_irqrestore+0x59/0x91
[ 0.000000] [<410c2982>] ? wake_up_klogd+0x8/0x33
[ 0.000000] [<410c2df5>] ? console_unlock+0x448/0x461
[ 0.000000] [<41d6d359>] dma_contiguous_reserve_area+0x27/0x47
[ 0.000000] [<41d6d4d1>] dma_contiguous_reserve+0x158/0x163
[ 0.000000] [<41d33e0f>] setup_arch+0x79b/0xc68
[ 0.000000] [<4184c0b4>] ? printk+0x1c/0x1e
[ 0.000000] [<41d2b7cf>] start_kernel+0x9c/0x456
[ 0.000000] [<41d2b2ca>] i386_start_kernel+0x79/0x7d

see detail: https://lkml.org/lkml/2014/10/8/708

It is because dma_contiguous_reserve() is called before initmem_init() in x86,
the variable high_memory is not initialized but accessed by __pa(high_memory)
in dma_contiguous_reserve().

This patch moves dma_contiguous_reserve() after initmem_init() so that
high_memory is initialized before accessed.

Reported-by: Fengguang Wu <[email protected]>
Signed-off-by: Weijie Yang <[email protected]>
---
arch/x86/kernel/setup.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 235cfd3..ab08aa2 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1128,7 +1128,6 @@ void __init setup_arch(char **cmdline_p)
setup_real_mode();

memblock_set_current_limit(get_max_mapped());
- dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);

/*
* NOTE: On x86-32, only from this point on, fixmaps are ready for use.
@@ -1159,6 +1158,7 @@ void __init setup_arch(char **cmdline_p)
early_acpi_boot_init();

initmem_init();
+ dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);

/*
* Reserve memory for crash kernel after SRAT is parsed so that it
--
1.7.0.4


2014-10-24 09:45:23

by Marek Szyprowski

[permalink] [raw]
Subject: Re: [PATCH] x86, cma: reserve dma contiguous area after initmem_init()

Hello,

On 2014-10-24 11:00, Weijie Yang wrote:
> Fengguang Wu reported a BUG: Int 6: CR2 (null) on x86 platform in
> 0-day Linux Kernel Performance Test:
>
> [ 0.000000] BRK [0x025ee000, 0x025eefff] PGTABLE
> [ 0.000000] cma: dma_contiguous_reserve(limit 13ffe000)
> [ 0.000000] cma: dma_contiguous_reserve: reserving 31 MiB for global area
> [ 0.000000] BUG: Int 6: CR2 (null)
> [ 0.000000] EDI c0000000 ESI (null) EBP 41c11ea4 EBX 425cc101
> [ 0.000000] ESP 41c11e98 ES 0000007b DS 0000007b
> [ 0.000000] EDX 00000001 ECX (null) EAX 41cd8150
> [ 0.000000] vec 00000006 err (null) EIP 41072227 CS 00000060 flg 00210002
> [ 0.000000] Stack: 425cc150 (null) (null) 41c11ef4 41d4ee4d (null) 13ffe000 41c11ec4
> [ 0.000000] 41c2d900 (null) 13ffe000 (null) 4185793e 0000002e 410c2982 41c11f00
> [ 0.000000] 410c2df5 (null) (null) (null) 425cc150 00013efe (null) 41c11f28
> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.17.0-next-20141008 #815
> [ 0.000000] 00000000 425cc101 41c11e48 41850786 41c11ea4 41d2b1db 41d95f71 00000006
> [ 0.000000] 00000000 c0000000 00000000 41c11ea4 425cc101 41c11e98 0000007b 0000007b
> [ 0.000000] 00000001 00000000 41cd8150 00000006 00000000 41072227 00000060 00210002
> [ 0.000000] Call Trace:
> [ 0.000000] [<41850786>] dump_stack+0x16/0x18
> [ 0.000000] [<41d2b1db>] early_idt_handler+0x6b/0x6b
> [ 0.000000] [<41072227>] ? __phys_addr+0x2e/0xca
> [ 0.000000] [<41d4ee4d>] cma_declare_contiguous+0x3c/0x2d7
> [ 0.000000] [<4185793e>] ? _raw_spin_unlock_irqrestore+0x59/0x91
> [ 0.000000] [<410c2982>] ? wake_up_klogd+0x8/0x33
> [ 0.000000] [<410c2df5>] ? console_unlock+0x448/0x461
> [ 0.000000] [<41d6d359>] dma_contiguous_reserve_area+0x27/0x47
> [ 0.000000] [<41d6d4d1>] dma_contiguous_reserve+0x158/0x163
> [ 0.000000] [<41d33e0f>] setup_arch+0x79b/0xc68
> [ 0.000000] [<4184c0b4>] ? printk+0x1c/0x1e
> [ 0.000000] [<41d2b7cf>] start_kernel+0x9c/0x456
> [ 0.000000] [<41d2b2ca>] i386_start_kernel+0x79/0x7d
>
> see detail: https://lkml.org/lkml/2014/10/8/708
>
> It is because dma_contiguous_reserve() is called before initmem_init() in x86,
> the variable high_memory is not initialized but accessed by __pa(high_memory)
> in dma_contiguous_reserve().
>
> This patch moves dma_contiguous_reserve() after initmem_init() so that
> high_memory is initialized before accessed.
>
> Reported-by: Fengguang Wu <[email protected]>
> Signed-off-by: Weijie Yang <[email protected]>

Acked-by: Marek Szyprowski <[email protected]>

> ---
> arch/x86/kernel/setup.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 235cfd3..ab08aa2 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -1128,7 +1128,6 @@ void __init setup_arch(char **cmdline_p)
> setup_real_mode();
>
> memblock_set_current_limit(get_max_mapped());
> - dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
>
> /*
> * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
> @@ -1159,6 +1158,7 @@ void __init setup_arch(char **cmdline_p)
> early_acpi_boot_init();
>
> initmem_init();
> + dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
>
> /*
> * Reserve memory for crash kernel after SRAT is parsed so that it

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland

2014-10-24 16:38:27

by Michal Nazarewicz

[permalink] [raw]
Subject: Re: [PATCH] x86, cma: reserve dma contiguous area after initmem_init()

On Fri, Oct 24 2014, Weijie Yang <[email protected]> wrote:
> Fengguang Wu reported a BUG: Int 6: CR2 (null) on x86 platform in
> 0-day Linux Kernel Performance Test:
>
> [ 0.000000] BRK [0x025ee000, 0x025eefff] PGTABLE
> [ 0.000000] cma: dma_contiguous_reserve(limit 13ffe000)
> [ 0.000000] cma: dma_contiguous_reserve: reserving 31 MiB for global area
> [ 0.000000] BUG: Int 6: CR2 (null)
> [ 0.000000] EDI c0000000 ESI (null) EBP 41c11ea4 EBX 425cc101
> [ 0.000000] ESP 41c11e98 ES 0000007b DS 0000007b
> [ 0.000000] EDX 00000001 ECX (null) EAX 41cd8150
> [ 0.000000] vec 00000006 err (null) EIP 41072227 CS 00000060 flg 00210002
> [ 0.000000] Stack: 425cc150 (null) (null) 41c11ef4 41d4ee4d (null) 13ffe000 41c11ec4
> [ 0.000000] 41c2d900 (null) 13ffe000 (null) 4185793e 0000002e 410c2982 41c11f00
> [ 0.000000] 410c2df5 (null) (null) (null) 425cc150 00013efe (null) 41c11f28
> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.17.0-next-20141008 #815
> [ 0.000000] 00000000 425cc101 41c11e48 41850786 41c11ea4 41d2b1db 41d95f71 00000006
> [ 0.000000] 00000000 c0000000 00000000 41c11ea4 425cc101 41c11e98 0000007b 0000007b
> [ 0.000000] 00000001 00000000 41cd8150 00000006 00000000 41072227 00000060 00210002
> [ 0.000000] Call Trace:
> [ 0.000000] [<41850786>] dump_stack+0x16/0x18
> [ 0.000000] [<41d2b1db>] early_idt_handler+0x6b/0x6b
> [ 0.000000] [<41072227>] ? __phys_addr+0x2e/0xca
> [ 0.000000] [<41d4ee4d>] cma_declare_contiguous+0x3c/0x2d7
> [ 0.000000] [<4185793e>] ? _raw_spin_unlock_irqrestore+0x59/0x91
> [ 0.000000] [<410c2982>] ? wake_up_klogd+0x8/0x33
> [ 0.000000] [<410c2df5>] ? console_unlock+0x448/0x461
> [ 0.000000] [<41d6d359>] dma_contiguous_reserve_area+0x27/0x47
> [ 0.000000] [<41d6d4d1>] dma_contiguous_reserve+0x158/0x163
> [ 0.000000] [<41d33e0f>] setup_arch+0x79b/0xc68
> [ 0.000000] [<4184c0b4>] ? printk+0x1c/0x1e
> [ 0.000000] [<41d2b7cf>] start_kernel+0x9c/0x456
> [ 0.000000] [<41d2b2ca>] i386_start_kernel+0x79/0x7d
>
> see detail: https://lkml.org/lkml/2014/10/8/708
>
> It is because dma_contiguous_reserve() is called before initmem_init() in x86,
> the variable high_memory is not initialized but accessed by __pa(high_memory)
> in dma_contiguous_reserve().
>
> This patch moves dma_contiguous_reserve() after initmem_init() so that
> high_memory is initialized before accessed.
>
> Reported-by: Fengguang Wu <[email protected]>
> Signed-off-by: Weijie Yang <[email protected]>

Acked-by: Michal Nazarewicz <[email protected]>

> ---
> arch/x86/kernel/setup.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 235cfd3..ab08aa2 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -1128,7 +1128,6 @@ void __init setup_arch(char **cmdline_p)
> setup_real_mode();
>
> memblock_set_current_limit(get_max_mapped());
> - dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
>
> /*
> * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
> @@ -1159,6 +1158,7 @@ void __init setup_arch(char **cmdline_p)
> early_acpi_boot_init();
>
> initmem_init();
> + dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
>
> /*
> * Reserve memory for crash kernel after SRAT is parsed so that it
> --
> 1.7.0.4
>
>

--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał “mina86” Nazarewicz (o o)
ooo +--<[email protected]>--<xmpp:[email protected]>--ooO--(_)--Ooo--

2014-10-24 17:19:20

by Ingo Molnar

[permalink] [raw]
Subject: Re: [PATCH] x86, cma: reserve dma contiguous area after initmem_init()


* Weijie Yang <[email protected]> wrote:

> Fengguang Wu reported a BUG: Int 6: CR2 (null) on x86 platform in
> 0-day Linux Kernel Performance Test:
>
> [ 0.000000] BRK [0x025ee000, 0x025eefff] PGTABLE
> [ 0.000000] cma: dma_contiguous_reserve(limit 13ffe000)
> [ 0.000000] cma: dma_contiguous_reserve: reserving 31 MiB for global area
> [ 0.000000] BUG: Int 6: CR2 (null)
> [ 0.000000] EDI c0000000 ESI (null) EBP 41c11ea4 EBX 425cc101
> [ 0.000000] ESP 41c11e98 ES 0000007b DS 0000007b
> [ 0.000000] EDX 00000001 ECX (null) EAX 41cd8150
> [ 0.000000] vec 00000006 err (null) EIP 41072227 CS 00000060 flg 00210002
> [ 0.000000] Stack: 425cc150 (null) (null) 41c11ef4 41d4ee4d (null) 13ffe000 41c11ec4
> [ 0.000000] 41c2d900 (null) 13ffe000 (null) 4185793e 0000002e 410c2982 41c11f00
> [ 0.000000] 410c2df5 (null) (null) (null) 425cc150 00013efe (null) 41c11f28
> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.17.0-next-20141008 #815
> [ 0.000000] 00000000 425cc101 41c11e48 41850786 41c11ea4 41d2b1db 41d95f71 00000006
> [ 0.000000] 00000000 c0000000 00000000 41c11ea4 425cc101 41c11e98 0000007b 0000007b
> [ 0.000000] 00000001 00000000 41cd8150 00000006 00000000 41072227 00000060 00210002
> [ 0.000000] Call Trace:
> [ 0.000000] [<41850786>] dump_stack+0x16/0x18
> [ 0.000000] [<41d2b1db>] early_idt_handler+0x6b/0x6b
> [ 0.000000] [<41072227>] ? __phys_addr+0x2e/0xca
> [ 0.000000] [<41d4ee4d>] cma_declare_contiguous+0x3c/0x2d7
> [ 0.000000] [<4185793e>] ? _raw_spin_unlock_irqrestore+0x59/0x91
> [ 0.000000] [<410c2982>] ? wake_up_klogd+0x8/0x33
> [ 0.000000] [<410c2df5>] ? console_unlock+0x448/0x461
> [ 0.000000] [<41d6d359>] dma_contiguous_reserve_area+0x27/0x47
> [ 0.000000] [<41d6d4d1>] dma_contiguous_reserve+0x158/0x163
> [ 0.000000] [<41d33e0f>] setup_arch+0x79b/0xc68
> [ 0.000000] [<4184c0b4>] ? printk+0x1c/0x1e
> [ 0.000000] [<41d2b7cf>] start_kernel+0x9c/0x456
> [ 0.000000] [<41d2b2ca>] i386_start_kernel+0x79/0x7d
>
> see detail: https://lkml.org/lkml/2014/10/8/708
>
> It is because dma_contiguous_reserve() is called before initmem_init() in x86,
> the variable high_memory is not initialized but accessed by __pa(high_memory)
> in dma_contiguous_reserve().
>
> This patch moves dma_contiguous_reserve() after initmem_init() so that
> high_memory is initialized before accessed.
>
> Reported-by: Fengguang Wu <[email protected]>
> Signed-off-by: Weijie Yang <[email protected]>
> ---
> arch/x86/kernel/setup.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 235cfd3..ab08aa2 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -1128,7 +1128,6 @@ void __init setup_arch(char **cmdline_p)
> setup_real_mode();
>
> memblock_set_current_limit(get_max_mapped());
> - dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
>
> /*
> * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
> @@ -1159,6 +1158,7 @@ void __init setup_arch(char **cmdline_p)
> early_acpi_boot_init();
>
> initmem_init();
> + dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
>
> /*
> * Reserve memory for crash kernel after SRAT is parsed so that it

I think this might be a boot regression that went upstream via
akpm's tree, via the recent 'cma' change:

5ea3b1b2f8ad cma: add placement specifier for "cma=" kernel parameter

Next time around please put 'x86' into patches that
enable features on x86 and which change its early init
behavior. The 'cma: ...' prefix was rather misleading.

Thanks,

Ingo

Subject: [tip:x86/urgent] x86, cma: Reserve DMA contiguous area after initmem_init()

Commit-ID: 3c325f8233c35fb35dec3744ba01634aab4ea36a
Gitweb: http://git.kernel.org/tip/3c325f8233c35fb35dec3744ba01634aab4ea36a
Author: Weijie Yang <[email protected]>
AuthorDate: Fri, 24 Oct 2014 17:00:34 +0800
Committer: Ingo Molnar <[email protected]>
CommitDate: Tue, 28 Oct 2014 07:36:50 +0100

x86, cma: Reserve DMA contiguous area after initmem_init()

Fengguang Wu reported a boot crash on the x86 platform
via the 0-day Linux Kernel Performance Test:

cma: dma_contiguous_reserve: reserving 31 MiB for global area
BUG: Int 6: CR2 (null)
[<41850786>] dump_stack+0x16/0x18
[<41d2b1db>] early_idt_handler+0x6b/0x6b
[<41072227>] ? __phys_addr+0x2e/0xca
[<41d4ee4d>] cma_declare_contiguous+0x3c/0x2d7
[<41d6d359>] dma_contiguous_reserve_area+0x27/0x47
[<41d6d4d1>] dma_contiguous_reserve+0x158/0x163
[<41d33e0f>] setup_arch+0x79b/0xc68
[<41d2b7cf>] start_kernel+0x9c/0x456
[<41d2b2ca>] i386_start_kernel+0x79/0x7d

(See details at: https://lkml.org/lkml/2014/10/8/708)

It is because dma_contiguous_reserve() is called before
initmem_init() in x86, the variable high_memory is not
initialized but accessed by __pa(high_memory) in
dma_contiguous_reserve().

This patch moves dma_contiguous_reserve() after initmem_init()
so that high_memory is initialized before accessed.

Reported-by: Fengguang Wu <[email protected]>
Signed-off-by: Weijie Yang <[email protected]>
Acked-by: Andrew Morton <[email protected]>
Acked-by: Marek Szyprowski <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
Cc: [email protected]
Cc: 'Linux-MM' <[email protected]>
Cc: 'Weijie Yang' <[email protected]>
Link: http://lkml.kernel.org/r/000101cfef69%2431e528a0%2495af79e0%24%[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/kernel/setup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 235cfd3..ab08aa2 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1128,7 +1128,6 @@ void __init setup_arch(char **cmdline_p)
setup_real_mode();

memblock_set_current_limit(get_max_mapped());
- dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);

/*
* NOTE: On x86-32, only from this point on, fixmaps are ready for use.
@@ -1159,6 +1158,7 @@ void __init setup_arch(char **cmdline_p)
early_acpi_boot_init();

initmem_init();
+ dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);

/*
* Reserve memory for crash kernel after SRAT is parsed so that it