Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

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

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 45f1ff721c3273a93fd3fb47ecc30e139b03111d..367494dc67d9e89a34ae7273b737479349987aef 100644 (file)
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -217,7 +217,7 @@ static nokprobe_inline void set_current_kprobe(struct kprobe *p, struct pt_regs
        kcb->kprobe_saved_msr = regs->msr;
 }
 
-bool arch_function_offset_within_entry(unsigned long offset)
+bool arch_kprobe_on_func_entry(unsigned long offset)
 {
 #ifdef PPC64_ELF_ABI_v2
 #ifdef CONFIG_KPROBES_ON_FTRACE

diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 541df0b5b81530741586d6eaf382e9d1a425ac06..bd2684700b74cd5c97ada00a53fbea3242a15397 100644 (file)
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -267,8 +267,8 @@ extern int arch_init_kprobes(void);
 extern void show_registers(struct pt_regs *regs);
 extern void kprobes_inc_nmissed_count(struct kprobe *p);
 extern bool arch_within_kprobe_blacklist(unsigned long addr);
-extern bool arch_function_offset_within_entry(unsigned long offset);
-extern bool function_offset_within_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset);
+extern bool arch_kprobe_on_func_entry(unsigned long offset);
+extern bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset);
 
 extern bool within_kprobe_blacklist(unsigned long addr);
 

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 6756d750b31b5c8d044d793fe68f43f19f5bb3d1..a1606a4224e14eef5f9e51d5826fa2c6ad75ab32 100644 (file)
--- 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 b53c8d36916351156d8042b05b13bc5b8b717388..2c5221819be51e79f504235c131ee4dc93138a91 100644 (file)
--- 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;
                }

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 6f4882f8d61fb2e1f23000c581134f837722712c..87b43188667046c8a676b9bcbb3f2c7c315eb9bc 100644 (file)
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -273,6 +273,7 @@ struct perf_evsel *perf_evsel__new_cycles(void)
        struct perf_event_attr attr = {
                .type   = PERF_TYPE_HARDWARE,
                .config = PERF_COUNT_HW_CPU_CYCLES,
+               .exclude_kernel = 1,
        };
        struct perf_evsel *evsel;
 

diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c
index 6d542a4e0648eeabb0cb58eda0cefbfa03d1028a..8aef572d08890b3e051c604a83e99d31abf53778 100644 (file)
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -50,7 +50,7 @@ int unwind__prepare_access(struct thread *thread, struct map *map,
 
        if (!ops) {
                pr_err("unwind: target platform=%s is not supported\n", arch);
-               return -1;
+               return 0;
        }
 out_register:
        unwind__register_ops(thread, ops);