x86-64: Add vsyscall:emulate_vsyscall trace event

Vsyscall emulation is slow, so make it easy to track down.

Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/cdaad7da946a80b200df16647c1700db3e1171e9.1312378163.git.luto@mit.edu
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Andy Lutomirski 2011-08-03 09:31:54 -04:00 committed by H. Peter Anvin
parent 318f5a2a67
commit c149a665ac
2 changed files with 35 additions and 0 deletions

View file

@ -50,6 +50,9 @@
#include <asm/vgtod.h>
#include <asm/traps.h>
#define CREATE_TRACE_POINTS
#include "vsyscall_trace.h"
DEFINE_VVAR(int, vgetcpu_mode);
DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data) =
{
@ -146,6 +149,9 @@ void dotraplinkage do_emulate_vsyscall(struct pt_regs *regs, long error_code)
* and int 0xcc is two bytes long.
*/
vsyscall_nr = addr_to_vsyscall_nr(regs->ip - 2);
trace_emulate_vsyscall(vsyscall_nr);
if (vsyscall_nr < 0) {
warn_bad_vsyscall(KERN_WARNING, regs,
"illegal int 0xcc (exploit attempt?)");

View file

@ -0,0 +1,29 @@
#undef TRACE_SYSTEM
#define TRACE_SYSTEM vsyscall
#if !defined(__VSYSCALL_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
#define __VSYSCALL_TRACE_H
#include <linux/tracepoint.h>
TRACE_EVENT(emulate_vsyscall,
TP_PROTO(int nr),
TP_ARGS(nr),
TP_STRUCT__entry(__field(int, nr)),
TP_fast_assign(
__entry->nr = nr;
),
TP_printk("nr = %d", __entry->nr)
);
#endif
#undef TRACE_INCLUDE_PATH
#define TRACE_INCLUDE_PATH ../../arch/x86/kernel
#define TRACE_INCLUDE_FILE vsyscall_trace
#include <trace/define_trace.h>