* [PATCH] powerpc: Fix audit crash due to save/restore PPR changes
@ 2013-04-15 1:44 Alistair Popple
2013-04-16 5:38 ` Haren Myneni
0 siblings, 1 reply; 2+ messages in thread
From: Alistair Popple @ 2013-04-15 1:44 UTC (permalink / raw)
To: sfr, benh; +Cc: mikey, linuxppc-dev, haren
The current mainline crashes when hitting userspace with the following:
kernel BUG at /home/alistair/Source/linux-stable/kernel/auditsc.c:1769!
cpu 0x1: Vector: 700 (Program Check) at [c000000023883a60]
pc: c0000000001047a8: .__audit_syscall_entry+0x38/0x130
lr: c00000000000ed64: .do_syscall_trace_enter+0xc4/0x270
sp: c000000023883ce0
msr: 8000000000029032
current = 0xc000000023800000
paca = 0xc00000000f080380 softe: 0 irq_happened: 0x01
pid = 1629, comm = start_udev
kernel BUG at /home/alistair/Source/linux-stable/kernel/auditsc.c:1769!
enter ? for help
[c000000023883d80] c00000000000ed64 .do_syscall_trace_enter+0xc4/0x270
[c000000023883e30] c000000000009b08 syscall_dotrace+0xc/0x38
--- Exception: c00 (System Call) at 0000008010ec50dc
Bisecting found the following patch caused it:
commit 44e9309f1f357794b7ae93d5f3e3e6f11d2b8a7f
Author: Haren Myneni <haren@linux.vnet.ibm.com>
powerpc: Implement PPR save/restore
It was found this patch corrupted r9 when calling
SET_DEFAULT_THREAD_PPR()
Using r10 as a scratch register instead of r9 solved the problem.
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Acked-by: Michael Neuling <mikey@neuling.org>
---
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 256c5bf..3acb1a0 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -304,7 +304,7 @@ syscall_exit_work:
subi r12,r12,TI_FLAGS
4: /* Anything else left to do? */
- SET_DEFAULT_THREAD_PPR(r3, r9) /* Set thread.ppr = 3 */
+ SET_DEFAULT_THREAD_PPR(r3, r10) /* Set thread.ppr = 3 */
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP)
beq .ret_from_except_lite
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] powerpc: Fix audit crash due to save/restore PPR changes
2013-04-15 1:44 [PATCH] powerpc: Fix audit crash due to save/restore PPR changes Alistair Popple
@ 2013-04-16 5:38 ` Haren Myneni
0 siblings, 0 replies; 2+ messages in thread
From: Haren Myneni @ 2013-04-16 5:38 UTC (permalink / raw)
To: Alistair Popple; +Cc: sfr, mikey, linuxppc-dev
On 04/14/2013 06:44 PM, Alistair Popple wrote:
> The current mainline crashes when hitting userspace with the following:
>
> kernel BUG at /home/alistair/Source/linux-stable/kernel/auditsc.c:1769!
> cpu 0x1: Vector: 700 (Program Check) at [c000000023883a60]
> pc: c0000000001047a8: .__audit_syscall_entry+0x38/0x130
> lr: c00000000000ed64: .do_syscall_trace_enter+0xc4/0x270
> sp: c000000023883ce0
> msr: 8000000000029032
> current = 0xc000000023800000
> paca = 0xc00000000f080380 softe: 0 irq_happened: 0x01
> pid = 1629, comm = start_udev
> kernel BUG at /home/alistair/Source/linux-stable/kernel/auditsc.c:1769!
> enter ? for help
> [c000000023883d80] c00000000000ed64 .do_syscall_trace_enter+0xc4/0x270
> [c000000023883e30] c000000000009b08 syscall_dotrace+0xc/0x38
> --- Exception: c00 (System Call) at 0000008010ec50dc
>
> Bisecting found the following patch caused it:
>
> commit 44e9309f1f357794b7ae93d5f3e3e6f11d2b8a7f
> Author: Haren Myneni <haren@linux.vnet.ibm.com>
> powerpc: Implement PPR save/restore
>
> It was found this patch corrupted r9 when calling
> SET_DEFAULT_THREAD_PPR()
>
> Using r10 as a scratch register instead of r9 solved the problem.
Thanks for fixing. Sorry I missed it
Acked-by: Haren Myneni <haren@us.ibm.com>
>
> Signed-off-by: Alistair Popple <alistair@popple.id.au>
> Acked-by: Michael Neuling <mikey@neuling.org>
> ---
>
> diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
> index 256c5bf..3acb1a0 100644
> --- a/arch/powerpc/kernel/entry_64.S
> +++ b/arch/powerpc/kernel/entry_64.S
> @@ -304,7 +304,7 @@ syscall_exit_work:
> subi r12,r12,TI_FLAGS
>
> 4: /* Anything else left to do? */
> - SET_DEFAULT_THREAD_PPR(r3, r9) /* Set thread.ppr = 3 */
> + SET_DEFAULT_THREAD_PPR(r3, r10) /* Set thread.ppr = 3 */
> andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP)
> beq .ret_from_except_lite
>
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
>
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2013-04-15 1:44 [PATCH] powerpc: Fix audit crash due to save/restore PPR changes Alistair Popple
2013-04-16 5:38 ` Haren Myneni
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