Commit c3931a87 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents c8b2ba83 dbf58062

arch/powerpc/kernel/kprobes.c

+1 −1
Original line number Diff line number Diff line
@@ -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

include/linux/kprobes.h

+2 −2
Original line number Diff line number Diff line
@@ -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);

kernel/kprobes.c

+24 −18
Original line number Diff line number Diff line
@@ -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;

	for (i = 0; i < num; i++) {

		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) {

kernel/trace/trace_kprobe.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

		}

tools/perf/util/evsel.c

+1 −0
Original line number Diff line number Diff line
@@ -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;

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