* [PATCH] powerpc/crypto/crc32c-vpmsum: Fix missing preempt_disable()
@ 2017-04-06 13:34 Michael Ellerman
2017-04-07 1:00 ` Daniel Axtens
2017-04-12 3:39 ` Michael Ellerman
0 siblings, 2 replies; 3+ messages in thread
From: Michael Ellerman @ 2017-04-06 13:34 UTC (permalink / raw)
To: linuxppc-dev; +Cc: anton
In crc32c_vpmsum() we call enable_kernel_altivec() without first
disabling preemption, which is not allowed:
WARNING: CPU: 9 PID: 2949 at ../arch/powerpc/kernel/process.c:277 enable_kernel_altivec+0x100/0x120
Modules linked in: dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio libcrc32c vmx_crypto ...
CPU: 9 PID: 2949 Comm: docker Not tainted 4.11.0-rc5-compiler_gcc-6.3.1-00033-g308ac7563944 #381
...
NIP [c00000000001e320] enable_kernel_altivec+0x100/0x120
LR [d000000003df0910] crc32c_vpmsum+0x108/0x150 [crc32c_vpmsum]
Call Trace:
0xc138fd09 (unreliable)
crc32c_vpmsum+0x108/0x150 [crc32c_vpmsum]
crc32c_vpmsum_update+0x3c/0x60 [crc32c_vpmsum]
crypto_shash_update+0x88/0x1c0
crc32c+0x64/0x90 [libcrc32c]
dm_bm_checksum+0x48/0x80 [dm_persistent_data]
sb_check+0x84/0x120 [dm_thin_pool]
dm_bm_validate_buffer.isra.0+0xc0/0x1b0 [dm_persistent_data]
dm_bm_read_lock+0x80/0xf0 [dm_persistent_data]
__create_persistent_data_objects+0x16c/0x810 [dm_thin_pool]
dm_pool_metadata_open+0xb0/0x1a0 [dm_thin_pool]
pool_ctr+0x4cc/0xb60 [dm_thin_pool]
dm_table_add_target+0x16c/0x3c0
table_load+0x184/0x400
ctl_ioctl+0x2f0/0x560
dm_ctl_ioctl+0x38/0x50
do_vfs_ioctl+0xd8/0x920
SyS_ioctl+0x68/0xc0
system_call+0x38/0xfc
It used to be sufficient just to call pagefault_disable(), because that
also disabled preemption. But the two were decoupled in commit 8222dbe21e79
("sched/preempt, mm/fault: Decouple preemption from the page fault
logic") in mid 2015.
So add the missing preempt_disable/enable(). We should also call
disable_kernel_fp(), although it does nothing by default, there is a
debug switch to make it active and all enables should be paired with
disables.
Fixes: 6dd7a82cc54e ("crypto: powerpc - Add POWER8 optimised crc32c")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/crypto/crc32c-vpmsum_glue.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/powerpc/crypto/crc32c-vpmsum_glue.c b/arch/powerpc/crypto/crc32c-vpmsum_glue.c
index 411994551afc..f058e0c3e4d4 100644
--- a/arch/powerpc/crypto/crc32c-vpmsum_glue.c
+++ b/arch/powerpc/crypto/crc32c-vpmsum_glue.c
@@ -33,10 +33,13 @@ static u32 crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len)
}
if (len & ~VMX_ALIGN_MASK) {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
crc = __crc32c_vpmsum(crc, p, len & ~VMX_ALIGN_MASK);
+ disable_kernel_altivec();
pagefault_enable();
+ preempt_enable();
}
tail = len & VMX_ALIGN_MASK;
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] powerpc/crypto/crc32c-vpmsum: Fix missing preempt_disable()
2017-04-06 13:34 [PATCH] powerpc/crypto/crc32c-vpmsum: Fix missing preempt_disable() Michael Ellerman
@ 2017-04-07 1:00 ` Daniel Axtens
2017-04-12 3:39 ` Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: Daniel Axtens @ 2017-04-07 1:00 UTC (permalink / raw)
To: Michael Ellerman, linuxppc-dev; +Cc: anton
Hi Michael,
We'll also need a similar patch for the t10dif code that went in to
Herbert's next.
I will do a patch once I get my development environment up and going
again.
Regards,
Daniel
Michael Ellerman <mpe@ellerman.id.au> writes:
> In crc32c_vpmsum() we call enable_kernel_altivec() without first
> disabling preemption, which is not allowed:
>
> WARNING: CPU: 9 PID: 2949 at ../arch/powerpc/kernel/process.c:277 enable_kernel_altivec+0x100/0x120
> Modules linked in: dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio libcrc32c vmx_crypto ...
> CPU: 9 PID: 2949 Comm: docker Not tainted 4.11.0-rc5-compiler_gcc-6.3.1-00033-g308ac7563944 #381
> ...
> NIP [c00000000001e320] enable_kernel_altivec+0x100/0x120
> LR [d000000003df0910] crc32c_vpmsum+0x108/0x150 [crc32c_vpmsum]
> Call Trace:
> 0xc138fd09 (unreliable)
> crc32c_vpmsum+0x108/0x150 [crc32c_vpmsum]
> crc32c_vpmsum_update+0x3c/0x60 [crc32c_vpmsum]
> crypto_shash_update+0x88/0x1c0
> crc32c+0x64/0x90 [libcrc32c]
> dm_bm_checksum+0x48/0x80 [dm_persistent_data]
> sb_check+0x84/0x120 [dm_thin_pool]
> dm_bm_validate_buffer.isra.0+0xc0/0x1b0 [dm_persistent_data]
> dm_bm_read_lock+0x80/0xf0 [dm_persistent_data]
> __create_persistent_data_objects+0x16c/0x810 [dm_thin_pool]
> dm_pool_metadata_open+0xb0/0x1a0 [dm_thin_pool]
> pool_ctr+0x4cc/0xb60 [dm_thin_pool]
> dm_table_add_target+0x16c/0x3c0
> table_load+0x184/0x400
> ctl_ioctl+0x2f0/0x560
> dm_ctl_ioctl+0x38/0x50
> do_vfs_ioctl+0xd8/0x920
> SyS_ioctl+0x68/0xc0
> system_call+0x38/0xfc
>
> It used to be sufficient just to call pagefault_disable(), because that
> also disabled preemption. But the two were decoupled in commit 8222dbe21e79
> ("sched/preempt, mm/fault: Decouple preemption from the page fault
> logic") in mid 2015.
>
> So add the missing preempt_disable/enable(). We should also call
> disable_kernel_fp(), although it does nothing by default, there is a
> debug switch to make it active and all enables should be paired with
> disables.
>
> Fixes: 6dd7a82cc54e ("crypto: powerpc - Add POWER8 optimised crc32c")
> Cc: stable@vger.kernel.org # v4.8+
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> ---
> arch/powerpc/crypto/crc32c-vpmsum_glue.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/powerpc/crypto/crc32c-vpmsum_glue.c b/arch/powerpc/crypto/crc32c-vpmsum_glue.c
> index 411994551afc..f058e0c3e4d4 100644
> --- a/arch/powerpc/crypto/crc32c-vpmsum_glue.c
> +++ b/arch/powerpc/crypto/crc32c-vpmsum_glue.c
> @@ -33,10 +33,13 @@ static u32 crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len)
> }
>
> if (len & ~VMX_ALIGN_MASK) {
> + preempt_disable();
> pagefault_disable();
> enable_kernel_altivec();
> crc = __crc32c_vpmsum(crc, p, len & ~VMX_ALIGN_MASK);
> + disable_kernel_altivec();
> pagefault_enable();
> + preempt_enable();
> }
>
> tail = len & VMX_ALIGN_MASK;
> --
> 2.7.4
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: powerpc/crypto/crc32c-vpmsum: Fix missing preempt_disable()
2017-04-06 13:34 [PATCH] powerpc/crypto/crc32c-vpmsum: Fix missing preempt_disable() Michael Ellerman
2017-04-07 1:00 ` Daniel Axtens
@ 2017-04-12 3:39 ` Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: Michael Ellerman @ 2017-04-12 3:39 UTC (permalink / raw)
To: Michael Ellerman, linuxppc-dev; +Cc: anton
On Thu, 2017-04-06 at 13:34:38 UTC, Michael Ellerman wrote:
> In crc32c_vpmsum() we call enable_kernel_altivec() without first
> disabling preemption, which is not allowed:
>
> WARNING: CPU: 9 PID: 2949 at ../arch/powerpc/kernel/process.c:277 enable_kernel_altivec+0x100/0x120
> Modules linked in: dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio libcrc32c vmx_crypto ...
> CPU: 9 PID: 2949 Comm: docker Not tainted 4.11.0-rc5-compiler_gcc-6.3.1-00033-g308ac7563944 #381
> ...
> NIP [c00000000001e320] enable_kernel_altivec+0x100/0x120
> LR [d000000003df0910] crc32c_vpmsum+0x108/0x150 [crc32c_vpmsum]
> Call Trace:
> 0xc138fd09 (unreliable)
> crc32c_vpmsum+0x108/0x150 [crc32c_vpmsum]
> crc32c_vpmsum_update+0x3c/0x60 [crc32c_vpmsum]
> crypto_shash_update+0x88/0x1c0
> crc32c+0x64/0x90 [libcrc32c]
> dm_bm_checksum+0x48/0x80 [dm_persistent_data]
> sb_check+0x84/0x120 [dm_thin_pool]
> dm_bm_validate_buffer.isra.0+0xc0/0x1b0 [dm_persistent_data]
> dm_bm_read_lock+0x80/0xf0 [dm_persistent_data]
> __create_persistent_data_objects+0x16c/0x810 [dm_thin_pool]
> dm_pool_metadata_open+0xb0/0x1a0 [dm_thin_pool]
> pool_ctr+0x4cc/0xb60 [dm_thin_pool]
> dm_table_add_target+0x16c/0x3c0
> table_load+0x184/0x400
> ctl_ioctl+0x2f0/0x560
> dm_ctl_ioctl+0x38/0x50
> do_vfs_ioctl+0xd8/0x920
> SyS_ioctl+0x68/0xc0
> system_call+0x38/0xfc
>
> It used to be sufficient just to call pagefault_disable(), because that
> also disabled preemption. But the two were decoupled in commit 8222dbe21e79
> ("sched/preempt, mm/fault: Decouple preemption from the page fault
> logic") in mid 2015.
>
> So add the missing preempt_disable/enable(). We should also call
> disable_kernel_fp(), although it does nothing by default, there is a
> debug switch to make it active and all enables should be paired with
> disables.
>
> Fixes: 6dd7a82cc54e ("crypto: powerpc - Add POWER8 optimised crc32c")
> Cc: stable@vger.kernel.org # v4.8+
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Applied to powerpc fixes.
https://git.kernel.org/powerpc/c/4749228f022893faf54a3dbc70796f
cheers
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-04-06 13:34 [PATCH] powerpc/crypto/crc32c-vpmsum: Fix missing preempt_disable() Michael Ellerman
2017-04-07 1:00 ` Daniel Axtens
2017-04-12 3:39 ` Michael Ellerman
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