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authorDave Hansen <dave.hansen@linux.intel.com>2015-06-07 20:37:03 +0200
committerIngo Molnar <mingo@kernel.org>2015-06-09 12:24:31 +0200
commite7126cf5f10aef1555cb99eddb7efff41bdf9566 (patch)
treefc24752c5b4a2202483c8e594d5c37ec948b9538 /arch/x86/include/asm/trace
parentx86/mpx: Introduce a boot-time disable flag (diff)
downloadlinux-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/x86/include/asm/trace')
-rw-r--r--arch/x86/include/asm/trace/mpx.h50
1 files changed, 50 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>