[PATCH v2 6/6] x86-64: Add vsyscall:emulate_vsyscall trace event
From: Andy Lutomirski <hidden>
Date: 2011-08-03 13:31:54
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Vsyscall emulation is slow, so make it easy to track down. Signed-off-by: Andy Lutomirski <redacted> --- arch/x86/kernel/vsyscall_64.c | 6 ++++++ arch/x86/kernel/vsyscall_trace.h | 29 +++++++++++++++++++++++++++++ 2 files changed, 35 insertions(+), 0 deletions(-) create mode 100644 arch/x86/kernel/vsyscall_trace.h
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 1725930..93a0d46 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c@@ -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?)");
diff --git a/arch/x86/kernel/vsyscall_trace.h b/arch/x86/kernel/vsyscall_trace.h
new file mode 100644
index 0000000..a8b2ede
--- /dev/null
+++ b/arch/x86/kernel/vsyscall_trace.h@@ -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>
--
1.7.6