From: Dave Hansen <dave@sr71.net>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, tglx@linutronix.de, Dave Hansen <dave@sr71.net>,
dave.hansen@linux.intel.com
Subject: [PATCH 03/16] x86, mpx: trace #BR exceptions
Date: Tue, 31 Mar 2015 17:46:27 -0700 [thread overview]
Message-ID: <20150401004627.341B9258@viggo.jf.intel.com> (raw)
In-Reply-To: <20150401004623.894DF37A@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
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>
---
b/arch/x86/include/asm/trace/mpx.h | 48 +++++++++++++++++++++++++++++++++++++
b/arch/x86/kernel/traps.c | 2 +
b/arch/x86/mm/mpx.c | 3 ++
3 files changed, 53 insertions(+)
diff -puN /dev/null arch/x86/include/asm/trace/mpx.h
--- /dev/null 2014-10-10 16:10:57.316716958 -0700
+++ b/arch/x86/include/asm/trace/mpx.h 2015-03-31 16:41:56.396286964 -0700
@@ -0,0 +1,48 @@
+#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(struct bndcsr *bndcsr),
+ TP_ARGS(bndcsr),
+
+ TP_STRUCT__entry(
+ __field(u64, bndcfgu)
+ __field(u64, bndstatus)
+ ),
+
+ TP_fast_assign(
+ __entry->bndcfgu = bndcsr->bndcfgu;
+ __entry->bndstatus = 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(struct bndcsr *bndcsr)
+{
+}
+
+#endif /* CONFIG_X86_INTEL_MPX */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH asm/trace/
+#define TRACE_INCLUDE_FILE mpx
+#endif /* _TRACE_MPX_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff -puN arch/x86/kernel/traps.c~x86-br-exception-trace arch/x86/kernel/traps.c
--- a/arch/x86/kernel/traps.c~x86-br-exception-trace 2015-03-31 16:41:56.391286739 -0700
+++ b/arch/x86/kernel/traps.c 2015-03-31 16:41:56.396286964 -0700
@@ -61,6 +61,7 @@
#include <asm/mach_traps.h>
#include <asm/alternative.h>
#include <asm/mpx.h>
+#include <asm/trace/mpx.h>
#include <asm/xsave.h>
#ifdef CONFIG_X86_64
@@ -401,6 +402,7 @@ dotraplinkage void do_bounds(struct pt_r
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 -puN arch/x86/mm/mpx.c~x86-br-exception-trace arch/x86/mm/mpx.c
--- a/arch/x86/mm/mpx.c~x86-br-exception-trace 2015-03-31 16:41:56.393286830 -0700
+++ b/arch/x86/mm/mpx.c 2015-03-31 16:41:56.397287010 -0700
@@ -18,6 +18,9 @@
#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]";
_
next prev parent reply other threads:[~2015-04-01 0:49 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-01 0:46 [PATCH 00/16] x86, mpx updates for 4.1 (take 4) Dave Hansen
2015-04-01 0:46 ` [PATCH 01/16] x86, fpu: wrap get_xsave_addr() to make it safer Dave Hansen
2015-04-22 10:40 ` Borislav Petkov
2015-04-22 13:16 ` Oleg Nesterov
2015-04-22 13:31 ` Borislav Petkov
2015-04-22 14:56 ` Dave Hansen
2015-04-22 15:17 ` Thomas Gleixner
2015-04-22 15:21 ` Borislav Petkov
2015-04-22 15:26 ` Thomas Gleixner
2015-04-22 16:02 ` Dave Hansen
2015-04-22 15:32 ` Oleg Nesterov
2015-04-22 15:58 ` Borislav Petkov
2015-04-01 0:46 ` [PATCH 02/16] x86, mpx: use new tsk_get_xsave_addr() Dave Hansen
2015-04-01 0:46 ` Dave Hansen [this message]
2015-04-01 0:46 ` [PATCH 04/16] x86, mpx: trace entry to bounds exception paths Dave Hansen
2015-04-01 0:46 ` [PATCH 05/16] x86, mpx: trace ranged MPX operations Dave Hansen
2015-04-01 0:46 ` [PATCH 06/16] x86, mpx: trace allocation of new bounds tables Dave Hansen
2015-04-01 0:46 ` [PATCH 07/16] x86, mpx: boot-time disable Dave Hansen
2015-04-01 0:46 ` [PATCH 08/16] x86: make is_64bit_mm() widely available Dave Hansen
2015-04-01 0:46 ` [PATCH 09/16] x86: make __VIRTUAL_MASK safe to use on 32 bit Dave Hansen
2015-04-01 0:46 ` [PATCH 10/16] x86, mpx: we do not allocate the bounds directory Dave Hansen
2015-04-01 0:46 ` [PATCH 11/16] x86, mpx: remove redundant MPX_BNDCFG_ADDR_MASK Dave Hansen
2015-04-01 0:46 ` [PATCH 12/16] x86, mpx: Add temporary variable to reduce masking Dave Hansen
2015-04-01 0:46 ` [PATCH 13/16] x86, mpx: new directory entry to addr helper Dave Hansen
2015-04-01 0:46 ` [PATCH 14/16] x86, mpx: do 32-bit-only cmpxchg for 32-bit apps Dave Hansen
2015-04-01 0:46 ` [PATCH 15/16] x86, mpx: support 32-bit binaries on 64-bit kernel Dave Hansen
2015-04-01 0:46 ` [PATCH 16/16] x86, mpx: allow mixed binaries again Dave Hansen
2015-04-21 15:39 ` [PATCH 00/16] x86, mpx updates for 4.1 (take 4) Dave Hansen
2015-04-22 10:49 ` Borislav Petkov
2015-04-22 14:43 ` Dave Hansen
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