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| author | Dave Hansen <dave.hansen@linux.intel.com> | 2015-06-07 20:37:03 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-06-09 12:24:31 +0200 |
| commit | e7126cf5f10aef1555cb99eddb7efff41bdf9566 (patch) | |
| tree | fc24752c5b4a2202483c8e594d5c37ec948b9538 /arch | |
| parent | x86/mpx: Introduce a boot-time disable flag (diff) | |
| download | linux-e7126cf5f10aef1555cb99eddb7efff41bdf9566.tar.xz linux-e7126cf5f10aef1555cb99eddb7efff41bdf9566.zip | |
x86/mpx: Trace #BR exceptions
This is the first in a series of MPX tracing patches.
I've found these extremely useful in the process of
debugging applications and the kernel code itself.
This exception hooks in to the bounds (#BR) exception
very early and allows capturing the key registers which
would influence how the exception is handled.
Note that bndcfgu/bndstatus are technically still
64-bit registers even in 32-bit mode.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150607183703.5FE2619A@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/trace/mpx.h | 50 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 2 | ||||
| -rw-r--r-- | arch/x86/mm/mpx.c | 3 |
3 files changed, 55 insertions, 0 deletions
diff --git a/arch/x86/include/asm/trace/mpx.h b/arch/x86/include/asm/trace/mpx.h new file mode 100644 index 000000000000..5c03ec8a90d6 --- /dev/null +++ b/arch/x86/include/asm/trace/mpx.h @@ -0,0 +1,50 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM mpx + +#if !defined(_TRACE_MPX_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_MPX_H + +#include <linux/tracepoint.h> + +#ifdef CONFIG_X86_INTEL_MPX + +TRACE_EVENT(bounds_exception_mpx, + + TP_PROTO(const struct bndcsr *bndcsr), + TP_ARGS(bndcsr), + + TP_STRUCT__entry( + __field(u64, bndcfgu) + __field(u64, bndstatus) + ), + + TP_fast_assign( + /* need to get rid of the 'const' on bndcsr */ + __entry->bndcfgu = (u64)bndcsr->bndcfgu; + __entry->bndstatus = (u64)bndcsr->bndstatus; + ), + + TP_printk("bndcfgu:0x%llx bndstatus:0x%llx", + __entry->bndcfgu, + __entry->bndstatus) +); + +#else + +/* + * This gets used outside of MPX-specific code, so we need a stub. + */ +static inline void trace_bounds_exception_mpx(const struct bndcsr *bndcsr) +{ +} + +#endif /* CONFIG_X86_INTEL_MPX */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH asm/trace/ +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE mpx +#endif /* _TRACE_MPX_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index cffff669be3f..36cb15b7b367 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -60,6 +60,7 @@ #include <asm/mach_traps.h> #include <asm/alternative.h> #include <asm/fpu/xstate.h> +#include <asm/trace/mpx.h> #include <asm/mpx.h> #ifdef CONFIG_X86_64 @@ -399,6 +400,7 @@ dotraplinkage void do_bounds(struct pt_regs *regs, long error_code) if (!bndcsr) goto exit_trap; + trace_bounds_exception_mpx(bndcsr); /* * The error code field of the BNDSTATUS register communicates status * information of a bound range exception #BR or operation involving diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c index d6e02f3adee0..1fef52c17fc8 100644 --- a/arch/x86/mm/mpx.c +++ b/arch/x86/mm/mpx.c @@ -17,6 +17,9 @@ #include <asm/processor.h> #include <asm/fpu/internal.h> +#define CREATE_TRACE_POINTS +#include <asm/trace/mpx.h> + static const char *mpx_mapping_name(struct vm_area_struct *vma) { return "[mpx]"; |