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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-09 10:49:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-09 10:49:47 -0700
commitc3931a87db9e840dc20f3b962668d477eaeb2f75 (patch)
treebf92c17ec96ed25b3407435b28be9da2110475bc /kernel
parentMerge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (diff)
parentkprobes: Ensure that jprobe probepoints are at function entry (diff)
downloadwireguard-linux-c3931a87db9e840dc20f3b962668d477eaeb2f75.tar.xz
wireguard-linux-c3931a87db9e840dc20f3b962668d477eaeb2f75.zip
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner: "A couple of fixes for perf and kprobes: - Add he missing exclude_kernel attribute for the precise_ip level so !CAP_SYS_ADMIN users get the proper results. - Warn instead of failing completely when perf has no unwind support for a particular architectiure built in. - Ensure that jprobes are at function entry and not at some random place" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kprobes: Ensure that jprobe probepoints are at function entry kprobes: Simplify register_jprobes() kprobes: Rename [arch_]function_offset_within_entry() to [arch_]kprobe_on_func_entry() perf unwind: Do not fail due to missing unwind support perf evsel: Set attr.exclude_kernel when probing max attr.precise_ip
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kprobes.c42
-rw-r--r--kernel/trace/trace_kprobe.c2
2 files changed, 25 insertions, 19 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 6756d750b31b..a1606a4224e1 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1771,24 +1771,13 @@ unsigned long __weak arch_deref_entry_point(void *entry)
int register_jprobes(struct jprobe **jps, int num)
{
- struct jprobe *jp;
int ret = 0, i;
if (num <= 0)
return -EINVAL;
+
for (i = 0; i < num; i++) {
- unsigned long addr, offset;
- jp = jps[i];
- addr = arch_deref_entry_point(jp->entry);
-
- /* Verify probepoint is a function entry point */
- if (kallsyms_lookup_size_offset(addr, NULL, &offset) &&
- offset == 0) {
- jp->kp.pre_handler = setjmp_pre_handler;
- jp->kp.break_handler = longjmp_break_handler;
- ret = register_kprobe(&jp->kp);
- } else
- ret = -EINVAL;
+ ret = register_jprobe(jps[i]);
if (ret < 0) {
if (i > 0)
@@ -1796,13 +1785,30 @@ int register_jprobes(struct jprobe **jps, int num)
break;
}
}
+
return ret;
}
EXPORT_SYMBOL_GPL(register_jprobes);
int register_jprobe(struct jprobe *jp)
{
- return register_jprobes(&jp, 1);
+ unsigned long addr, offset;
+ struct kprobe *kp = &jp->kp;
+
+ /*
+ * Verify probepoint as well as the jprobe handler are
+ * valid function entry points.
+ */
+ addr = arch_deref_entry_point(jp->entry);
+
+ if (kallsyms_lookup_size_offset(addr, NULL, &offset) && offset == 0 &&
+ kprobe_on_func_entry(kp->addr, kp->symbol_name, kp->offset)) {
+ kp->pre_handler = setjmp_pre_handler;
+ kp->break_handler = longjmp_break_handler;
+ return register_kprobe(kp);
+ }
+
+ return -EINVAL;
}
EXPORT_SYMBOL_GPL(register_jprobe);
@@ -1888,12 +1894,12 @@ static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs)
}
NOKPROBE_SYMBOL(pre_handler_kretprobe);
-bool __weak arch_function_offset_within_entry(unsigned long offset)
+bool __weak arch_kprobe_on_func_entry(unsigned long offset)
{
return !offset;
}
-bool function_offset_within_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset)
+bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset)
{
kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset);
@@ -1901,7 +1907,7 @@ bool function_offset_within_entry(kprobe_opcode_t *addr, const char *sym, unsign
return false;
if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset) ||
- !arch_function_offset_within_entry(offset))
+ !arch_kprobe_on_func_entry(offset))
return false;
return true;
@@ -1914,7 +1920,7 @@ int register_kretprobe(struct kretprobe *rp)
int i;
void *addr;
- if (!function_offset_within_entry(rp->kp.addr, rp->kp.symbol_name, rp->kp.offset))
+ if (!kprobe_on_func_entry(rp->kp.addr, rp->kp.symbol_name, rp->kp.offset))
return -EINVAL;
if (kretprobe_blacklist_size) {
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index b53c8d369163..2c5221819be5 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -720,7 +720,7 @@ static int create_trace_kprobe(int argc, char **argv)
return ret;
}
if (offset && is_return &&
- !function_offset_within_entry(NULL, symbol, offset)) {
+ !kprobe_on_func_entry(NULL, symbol, offset)) {
pr_info("Given offset is not valid for return probe.\n");
return -EINVAL;
}