linux-kernel - [PATCH v2] perf/annotate: Fix branch instruction with multiple operands

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20170601092959.f60d98912e8a1b66fd1e4c0e@arm.com>
Date:   Thu, 1 Jun 2017 09:29:59 -0500
From:   Kim Phillips <kim.phillips@....com>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:     Ravi Bangoria <ravi.bangoria@...ux.vnet.ibm.com>,
        <anton@...ba.org>, <peterz@...radead.org>, <mingo@...hat.com>,
        <alexander.shishkin@...ux.intel.com>, <treeze.taeung@...il.com>,
        <borntraeger@...ibm.com>, <linux-kernel@...r.kernel.org>,
        Robin Murphy <robin.murphy@....com>,
        Mark Rutland <mark.rutland@....com>
Subject: [PATCH v2] perf/annotate: Fix branch instruction with multiple
 operands

Perf annotate is dropping the cr* fields from branch instructions.
Fix it by adding support to display branch instructions having
multiple operands.

Power Arch objdump of int_sqrt:

 20.36 | c0000000004d2694:   subf   r10,r10,r3
       | c0000000004d2698: v bgt    cr6,c0000000004d26a0 <int_sqrt+0x40>
  1.82 | c0000000004d269c:   mr     r3,r10
 29.18 | c0000000004d26a0:   mr     r10,r8
       | c0000000004d26a4: v bgt    cr7,c0000000004d26ac <int_sqrt+0x4c>
       | c0000000004d26a8:   mr     r10,r7

Power Arch Before Patch:

 20.36 |       subf   r10,r10,r3
       |     v bgt    40
  1.82 |       mr     r3,r10
 29.18 | 40:   mr     r10,r8
       |     v bgt    4c
       |       mr     r10,r7

Power Arch After patch:

 20.36 |       subf   r10,r10,r3
       |     v bgt    cr6,40
  1.82 |       mr     r3,r10
 29.18 | 40:   mr     r10,r8
       |     v bgt    cr7,4c
       |       mr     r10,r7

Also support AArch64 conditional branch instructions, which can
have up to three operands:

Aarch64 Non-simplified (raw objdump) view:

       │ffff0000083cd11c: ↑ cbz    w0, ffff0000083cd100 <security_fil▒
...
  4.44 │ffff000│083cd134: ↓ tbnz   w0, #26, ffff0000083cd190 <securit▒
...
  1.37 │ffff000│083cd144: ↓ tbnz   w22, #5, ffff0000083cd1a4 <securit▒
       │ffff000│083cd148:   mov    w19, #0x20000                   //▒
  1.02 │ffff000│083cd14c: ↓ tbz    w22, #2, ffff0000083cd1ac <securit▒
...
  0.68 │ffff000└──3cd16c: ↑ cbnz   w0, ffff0000083cd120 <security_fil▒

Aarch64 Simplified, before this patch:

       │    ↑ cbz    40
...
  4.44 │   │↓ tbnz   w0, #26, ffff0000083cd190 <security_file_permiss▒
...
  1.37 │   │↓ tbnz   w22, #5, ffff0000083cd1a4 <security_file_permiss▒
       │   │  mov    w19, #0x20000                   // #131072
  1.02 │   │↓ tbz    w22, #2, ffff0000083cd1ac <security_file_permiss▒
...
  0.68 │   └──cbnz   60

the cbz operand is missing, and the tbz doesn't get simplified processing
at all because the parsing function failed to match an address.

Aarch64 Simplified, After this patch applied:

       │    ↑ cbz    w0, 40
...
  4.44 │   │↓ tbnz   w0, #26, d0
...
  1.37 │   │↓ tbnz   w22, #5, e4
       │   │  mov    w19, #0x20000                   // #131072
  1.02 │   │↓ tbz    w22, #2, ec
...
  0.68 │   └──cbnz   w0, 60

Reported-by: Anton Blanchard <anton@...ba.org>
Reported-by: Robin Murphy <robin.murphy@....com>
Cc: Mark Rutland <mark.rutland@....com>
Originally-by: Ravi Bangoria <ravi.bangoria@...ux.vnet.ibm.com>
Signed-off-by: Kim Phillips <kim.phillips@....com>
---
v2: addressing Arnaldo's clean-this-up comment:  merged commit texts
between Ravi's original, author changed in lieu of adding something I
hadn't known nor thought about possibly doing: Originally-by: Ravi.
Ravi, if that's not OK, provide an alternative means of keeping things
clean for Arnaldo, thanks.

 tools/perf/util/annotate.c | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 683f8340460c..3174930e7cea 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -239,10 +239,20 @@ static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *op
 	const char *s = strchr(ops->raw, '+');
 	const char *c = strchr(ops->raw, ',');
 
-	if (c++ != NULL)
+	/*
+	 * skip over possible up to 2 operands to get to address, e.g.:
+	 * tbnz	 w0, #26, ffff0000083cd190 <security_file_permission+0xd0>
+	 */
+	if (c++ != NULL) {
 		ops->target.addr = strtoull(c, NULL, 16);
-	else
+		if (!ops->target.addr) {
+			c = strchr(c, ',');
+			if (c++ != NULL)
+				ops->target.addr = strtoull(c, NULL, 16);
+		}
+	} else {
 		ops->target.addr = strtoull(ops->raw, NULL, 16);
+	}
 
 	if (s++ != NULL) {
 		ops->target.offset = strtoull(s, NULL, 16);
@@ -257,10 +267,27 @@ static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *op
 static int jump__scnprintf(struct ins *ins, char *bf, size_t size,
 			   struct ins_operands *ops)
 {
+	const char *c = strchr(ops->raw, ',');
+
 	if (!ops->target.addr || ops->target.offset < 0)
 		return ins__raw_scnprintf(ins, bf, size, ops);
 
-	return scnprintf(bf, size, "%-6.6s %" PRIx64, ins->name, ops->target.offset);
+	if (c != NULL) {
+		const char *c2 = strchr(c + 1, ',');
+
+		/* check for 3-op insn */
+		if (c2 != NULL)
+			c = c2;
+		c++;
+
+		/* mirror arch objdump's space-after-comma style */
+		if (*c == ' ')
+			c++;
+	}
+
+	return scnprintf(bf, size, "%-6.6s %.*s%" PRIx64,
+			 ins->name, c ? c - ops->raw : 0, ops->raw,
+			 ops->target.offset);
 }
 
 static struct ins_ops jump_ops = {
-- 
2.11.0