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| author | Alistair Popple <alistair@popple.id.au> | 2013-04-15 01:44:14 (GMT) |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2013-04-15 07:29:45 (GMT) |
| commit | 05e38e5d5d437c762c79428ae8434632a8ca2c5e (patch) | |
| tree | 24822ddcb81ca867d1b67106e74f75777dab1978 /arch/powerpc | |
| parent | f110c0c1926028a233830c6166e4d40314420823 (diff) | |
| download | linux-05e38e5d5d437c762c79428ae8434632a8ca2c5e.tar.xz | |
powerpc: Fix audit crash due to save/restore PPR changes
The current mainline crashes when hitting userspace with the following:
kernel BUG at 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 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>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 2 |
1 files changed, 1 insertions, 1 deletions
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 |