diff options
| author | Steven Rostedt <rostedt@goodmis.org> | 2010-12-23 22:46:06 +0300 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-01-21 06:08:33 +0300 |
| commit | 3cb5f1a3e58c0bd70d47d9907cc5c65192281dee (patch) | |
| tree | 066e31b7fc67a681ffaa1306df64e7b302744410 /arch/powerpc/include/asm/irqflags.h | |
| parent | c0337288ab165be17081d61d4ef13b79d3ac55d4 (diff) | |
| download | linux-3cb5f1a3e58c0bd70d47d9907cc5c65192281dee.tar.xz | |
powerpc/ppc64/tracing: Add stack frame to calls of trace_hardirqs_on/off
When an interrupt occurs in userspace, we can call trace_hardirqs_on/off()
With one level stack. But if we have irqsoff tracing enabled,
it checks both CALLER_ADDR0 and CALLER_ADDR1. The second call
goes two stack frames up. If this is from user space, then there may
not exist a second stack.
Add a second stack when calling trace_hardirqs_on/off() otherwise
the following oops might occur:
Oops: Kernel access of bad area, sig: 11 [#1]
PREEMPT SMP NR_CPUS=2 PA Semi PWRficient
last sysfs file: /sys/block/sda/size
Modules linked in: ohci_hcd ehci_hcd usbcore
NIP: c0000000000e1c00 LR: c0000000000034d4 CTR: 000000011012c440
REGS: c00000003e2f3af0 TRAP: 0300 Not tainted (2.6.37-rc6+)
MSR: 9000000000001032 <ME,IR,DR> CR: 48044444 XER: 20000000
DAR: 00000001ffb9db50, DSISR: 0000000040000000
TASK = c00000003e1a00a0[2088] 'emacs' THREAD: c00000003e2f0000 CPU: 1
GPR00: 0000000000000001 c00000003e2f3d70 c00000000084e0d0 c0000000008816e8
GPR04: 000000001034c678 000000001032e8f9 0000000010336540 0000000040020000
GPR08: 0000000040020000 00000001ffb9db40 c00000003e2f3e30 0000000060000000
GPR12: 100000000000f032 c00000000fff0280 000000001032e8c9 0000000000000008
GPR16: 00000000105be9c0 00000000105be950 00000000105be9b0 00000000105be950
GPR20: 00000000ffb9dc50 00000000ffb9dbf0 00000000102f0000 00000000102f0000
GPR24: 00000000102e0000 00000000102f0000 0000000010336540 c0000000009ded38
GPR28: 00000000102e0000 c0000000000034d4 c0000000007ccb10 c00000003e2f3d70
NIP [c0000000000e1c00] .trace_hardirqs_off+0xb0/0x1d0
LR [c0000000000034d4] decrementer_common+0xd4/0x100
Call Trace:
[c00000003e2f3d70] [c00000003e2f3e30] 0xc00000003e2f3e30 (unreliable)
[c00000003e2f3e30] [c0000000000034d4] decrementer_common+0xd4/0x100
Instruction dump:
81690000 7f8b0000 419e0018 f84a0028 60000000 60000000 60000000 e95f0000
80030000 e92a0000 eb6301f8 2f800000 <eb890010> 41fe00dc a06d000a eb1e8050
---[ end trace 4ec7fd2be9240928 ]---
Reported-by: Joerg Sommer <joerg@alea.gnuu.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include/asm/irqflags.h')
| -rw-r--r-- | arch/powerpc/include/asm/irqflags.h | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/arch/powerpc/include/asm/irqflags.h b/arch/powerpc/include/asm/irqflags.h index b85d8ddbb666..b0b06d85788d 100644 --- a/arch/powerpc/include/asm/irqflags.h +++ b/arch/powerpc/include/asm/irqflags.h @@ -12,24 +12,44 @@ #else #ifdef CONFIG_TRACE_IRQFLAGS +#ifdef CONFIG_IRQSOFF_TRACER +/* + * Since the ftrace irqsoff latency trace checks CALLER_ADDR1, + * which is the stack frame here, we need to force a stack frame + * in case we came from user space. + */ +#define TRACE_WITH_FRAME_BUFFER(func) \ + mflr r0; \ + stdu r1, -32(r1); \ + std r0, 16(r1); \ + stdu r1, -32(r1); \ + bl func; \ + ld r1, 0(r1); \ + ld r1, 0(r1); +#else +#define TRACE_WITH_FRAME_BUFFER(func) \ + bl func; +#endif + /* * Most of the CPU's IRQ-state tracing is done from assembly code; we * have to call a C function so call a wrapper that saves all the * C-clobbered registers. */ -#define TRACE_ENABLE_INTS bl .trace_hardirqs_on -#define TRACE_DISABLE_INTS bl .trace_hardirqs_off -#define TRACE_AND_RESTORE_IRQ_PARTIAL(en,skip) \ - cmpdi en,0; \ - bne 95f; \ - stb en,PACASOFTIRQEN(r13); \ - bl .trace_hardirqs_off; \ - b skip; \ -95: bl .trace_hardirqs_on; \ +#define TRACE_ENABLE_INTS TRACE_WITH_FRAME_BUFFER(.trace_hardirqs_on) +#define TRACE_DISABLE_INTS TRACE_WITH_FRAME_BUFFER(.trace_hardirqs_off) + +#define TRACE_AND_RESTORE_IRQ_PARTIAL(en,skip) \ + cmpdi en,0; \ + bne 95f; \ + stb en,PACASOFTIRQEN(r13); \ + TRACE_WITH_FRAME_BUFFER(.trace_hardirqs_off) \ + b skip; \ +95: TRACE_WITH_FRAME_BUFFER(.trace_hardirqs_on) \ li en,1; #define TRACE_AND_RESTORE_IRQ(en) \ TRACE_AND_RESTORE_IRQ_PARTIAL(en,96f); \ - stb en,PACASOFTIRQEN(r13); \ + stb en,PACASOFTIRQEN(r13); \ 96: #else #define TRACE_ENABLE_INTS |