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Commit 4e67b2a5 authored by Kim Phillips's avatar Kim Phillips Committed by Arnaldo Carvalho de Melo
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perf annotate: Fix parsing aarch64 branch instructions after objdump update 

Starting with binutils 2.28, aarch64 objdump adds comments to the
disassembly output to show the alternative names of a condition code
[1].

It is assumed that commas in objdump comments could occur in other
arches now or in the future, so this fix is arch-independent.

The fix could have been done with arm64 specific jump__parse and
jump__scnprintf functions, but the jump__scnprintf instruction would
have to have its comment character be a literal, since the scnprintf
functions cannot receive a struct arch easily.

This inconvenience also applies to the generic jump__scnprintf, which is
why we add a raw_comment pointer to struct ins_operands, so the __parse
function assigns it to be re-used by its corresponding __scnprintf
function.

Example differences in 'perf annotate --stdio2' output on an aarch64
perf.data file:

BEFORE: → b.cs   ffff200008133d1c <unwind_frame+0x18c>  // b.hs, dffff7ecc47b
AFTER : ↓ b.cs   18c

BEFORE: → b.cc   ffff200008d8d9cc <get_alloc_profile+0x31c>  // b.lo, b.ul, dffff727295b
AFTER : ↓ b.cc   31c

The branch target labels 18c and 31c also now appear in the output:

BEFORE:        add    x26, x29, #0x80
AFTER : 18c:   add    x26, x29, #0x80

BEFORE:        add    x21, x21, #0x8
AFTER : 31c:   add    x21, x21, #0x8

The Fixes: tag below is added so stable branches will get the update; it
doesn't necessarily mean that commit was broken at the time, rather it
didn't withstand the aarch64 objdump update.

Tested no difference in output for sample x86_64, power arch perf.data files.

[1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=bb7eff5206e4795ac79c177a80fe9f4630aaf730



Signed-off-by: default avatarKim Phillips <kim.phillips@arm.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Fixes: b13bbeee ("perf annotate: Fix branch instruction with multiple operands")
Link: http://lkml.kernel.org/r/20180827125340.a2f7e291901d17cea05daba4@arm.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent fa694160

tools/perf/util/annotate.c

+21 −1
Original line number Diff line number Diff line
@@ -282,7 +282,19 @@ bool ins__is_call(const struct ins *ins) 
	return ins->ops == &call_ops || ins->ops == &s390_call_ops;

}



static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *ops, struct map_symbol *ms)

/*

 * Prevents from matching commas in the comment section, e.g.:

 * ffff200008446e70:       b.cs    ffff2000084470f4 <generic_exec_single+0x314>  // b.hs, b.nlast

 */

static inline const char *validate_comma(const char *c, struct ins_operands *ops)

{

	if (ops->raw_comment && c > ops->raw_comment)

		return NULL;



	return c;

}



static int jump__parse(struct arch *arch, struct ins_operands *ops, struct map_symbol *ms)

{

	struct map *map = ms->map;

	struct symbol *sym = ms->sym;
@@ -291,6 +303,10 @@ static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *op 
	};

	const char *c = strchr(ops->raw, ',');

	u64 start, end;



	ops->raw_comment = strchr(ops->raw, arch->objdump.comment_char);

	c = validate_comma(c, ops);



	/*

	 * Examples of lines to parse for the _cpp_lex_token@@Base

	 * function:
@@ -310,6 +326,7 @@ static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *op 
		ops->target.addr = strtoull(c, NULL, 16);

		if (!ops->target.addr) {

			c = strchr(c, ',');

			c = validate_comma(c, ops);

			if (c++ != NULL)

				ops->target.addr = strtoull(c, NULL, 16);

		}
@@ -367,9 +384,12 @@ static int jump__scnprintf(struct ins *ins, char *bf, size_t size, 
		return scnprintf(bf, size, "%-6s %s", ins->name, ops->target.sym->name);



	c = strchr(ops->raw, ',');

	c = validate_comma(c, ops);



	if (c != NULL) {

		const char *c2 = strchr(c + 1, ',');



		c2 = validate_comma(c2, ops);

		/* check for 3-op insn */

		if (c2 != NULL)

			c = c2;

tools/perf/util/annotate.h

+1 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ struct ins { 


struct ins_operands {

	char	*raw;

	char	*raw_comment;

	struct {

		char	*raw;

		char	*name;