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authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-06 12:30:52 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-06 12:30:52 -0400
commit4aed2fd8e3181fea7c09ba79cf64e7e3f4413bf9 (patch)
tree1f69733e5daab4915a76a41de0e4d1dc61e12cfb /arch/x86/kernel/kprobes.c
parent3a3527b6461b1298cc53ce72f336346739297ac8 (diff)
parentfc9ea5a1e53ee54f681e226d735008e2a6f8f470 (diff)
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (162 commits) tracing/kprobes: unregister_trace_probe needs to be called under mutex perf: expose event__process function perf events: Fix mmap offset determination perf, powerpc: fsl_emb: Restore setting perf_sample_data.period perf, powerpc: Convert the FSL driver to use local64_t perf tools: Don't keep unreferenced maps when unmaps are detected perf session: Invalidate last_match when removing threads from rb_tree perf session: Free the ref_reloc_sym memory at the right place x86,mmiotrace: Add support for tracing STOS instruction perf, sched migration: Librarize task states and event headers helpers perf, sched migration: Librarize the GUI class perf, sched migration: Make the GUI class client agnostic perf, sched migration: Make it vertically scrollable perf, sched migration: Parameterize cpu height and spacing perf, sched migration: Fix key bindings perf, sched migration: Ignore unhandled task states perf, sched migration: Handle ignored migrate out events perf: New migration tool overview tracing: Drop cpparg() macro perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call ... Fix up trivial conflicts in Makefile and drivers/cpufreq/cpufreq.c
Diffstat (limited to 'arch/x86/kernel/kprobes.c')
-rw-r--r--arch/x86/kernel/kprobes.c33
1 files changed, 17 insertions, 16 deletions
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 675879b65ce6..1bfb6cf4dd55 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -126,16 +126,22 @@ static void __kprobes synthesize_reljump(void *from, void *to)
126} 126}
127 127
128/* 128/*
129 * Check for the REX prefix which can only exist on X86_64 129 * Skip the prefixes of the instruction.
130 * X86_32 always returns 0
131 */ 130 */
132static int __kprobes is_REX_prefix(kprobe_opcode_t *insn) 131static kprobe_opcode_t *__kprobes skip_prefixes(kprobe_opcode_t *insn)
133{ 132{
133 insn_attr_t attr;
134
135 attr = inat_get_opcode_attribute((insn_byte_t)*insn);
136 while (inat_is_legacy_prefix(attr)) {
137 insn++;
138 attr = inat_get_opcode_attribute((insn_byte_t)*insn);
139 }
134#ifdef CONFIG_X86_64 140#ifdef CONFIG_X86_64
135 if ((*insn & 0xf0) == 0x40) 141 if (inat_is_rex_prefix(attr))
136 return 1; 142 insn++;
137#endif 143#endif
138 return 0; 144 return insn;
139} 145}
140 146
141/* 147/*
@@ -272,6 +278,9 @@ static int __kprobes can_probe(unsigned long paddr)
272 */ 278 */
273static int __kprobes is_IF_modifier(kprobe_opcode_t *insn) 279static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
274{ 280{
281 /* Skip prefixes */
282 insn = skip_prefixes(insn);
283
275 switch (*insn) { 284 switch (*insn) {
276 case 0xfa: /* cli */ 285 case 0xfa: /* cli */
277 case 0xfb: /* sti */ 286 case 0xfb: /* sti */
@@ -280,13 +289,6 @@ static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
280 return 1; 289 return 1;
281 } 290 }
282 291
283 /*
284 * on X86_64, 0x40-0x4f are REX prefixes so we need to look
285 * at the next byte instead.. but of course not recurse infinitely
286 */
287 if (is_REX_prefix(insn))
288 return is_IF_modifier(++insn);
289
290 return 0; 292 return 0;
291} 293}
292 294
@@ -803,9 +805,8 @@ static void __kprobes resume_execution(struct kprobe *p,
803 unsigned long orig_ip = (unsigned long)p->addr; 805 unsigned long orig_ip = (unsigned long)p->addr;
804 kprobe_opcode_t *insn = p->ainsn.insn; 806 kprobe_opcode_t *insn = p->ainsn.insn;
805 807
806 /*skip the REX prefix*/ 808 /* Skip prefixes */
807 if (is_REX_prefix(insn)) 809 insn = skip_prefixes(insn);
808 insn++;
809 810
810 regs->flags &= ~X86_EFLAGS_TF; 811 regs->flags &= ~X86_EFLAGS_TF;
811 switch (*insn) { 812 switch (*insn) {