[PATCH 0/5] perf: Fixes for callchain ip handling and related tests

[PATCH 0/5] perf: Fixes for callchain ip handling and related tests

[Sandipan Das]

The first two patches fix the callchain ip filtering mechanism for
powerpc from skipping entries unecessarily by checking the status of
a function's return address in the stack.

The third patch fixes a shell test that fails on powerpc due to a
mismatch in the expected perf script output.

The fourth and fifth patches are generic fixes for the same shell
test.

--

Hi Arnaldo,

This series has fixes for the inet_pton shell test and depends
on the following patches from Kim Phillips:

[1] https://lkml.org/lkml/2018/6/29/570
[2] https://lkml.org/lkml/2018/6/29/568

I did see that you had replied saying that you have applied
these patches to your tree but I still do not see the changes
in the 'perf/core' and 'perf/urgent' branches. Assuming that
you would be pushing these changes, I applied Kim's patches
to my local tree manually before I started working on this
series.

--

Sandipan Das (5):
  perf powerpc: Fix callchain ip filtering
  perf powerpc: Fix callchain ip filtering when return address is in a
    register
  perf tests: Fix record+probe_libc_inet_pton.sh for powerpc64
  perf tests: Fix record+probe_libc_inet_pton.sh to ensure cleanups
  perf tests: Fix record+probe_libc_inet_pton.sh when event exists

 tools/perf/arch/powerpc/util/skip-callchain-idx.c  | 10 ++++--
 .../tests/shell/record+probe_libc_inet_pton.sh     | 36 +++++++++++++++++++---
 2 files changed, 38 insertions(+), 8 deletions(-)

-- 
2.14.4

[PATCH 1/5] perf powerpc: Fix callchain ip filtering

[Sandipan Das]

For powerpc64, redundant entries in the callchain are filtered out by
determining the state of the return address and the stack frame using
DWARF debug information. For making these filtering decisions we must
analyze the debug information for the location corresponding to the
program counter value, i.e. the first entry in the callchain, and not
the LR value; otherwise, perf may filter out either the second or the
third entry in the callchain incorrectly.

This can be observed on a powerpc64le system running Fedora 27 as shown
below.

Case 1 - Attaching a probe at inet_pton+0x8 (binary offset 0x15af28).
         Return address is still in LR and a new stack frame is not yet
         allocated. The LR value, i.e. the second entry, should not be
	 filtered out.

  # objdump -d /usr/lib64/libc-2.26.so | less
  ...
  000000000010eb10 <gaih_inet.constprop.7>:
  ...
    10fa48:       78 bb e4 7e     mr      r4,r23
    10fa4c:       0a 00 60 38     li      r3,10
    10fa50:       d9 b4 04 48     bl      15af28 <inet_pton+0x8>
    10fa54:       00 00 00 60     nop
    10fa58:       ac f4 ff 4b     b       10ef04 <gaih_inet.constprop.7+0x3f4>
  ...
  0000000000110450 <getaddrinfo>:
  ...
    1105a8:       54 00 ff 38     addi    r7,r31,84
    1105ac:       58 00 df 38     addi    r6,r31,88
    1105b0:       69 e5 ff 4b     bl      10eb18 <gaih_inet.constprop.7+0x8>
    1105b4:       78 1b 71 7c     mr      r17,r3
    1105b8:       50 01 7f e8     ld      r3,336(r31)
  ...
  000000000015af20 <inet_pton>:
    15af20:       0b 00 4c 3c     addis   r2,r12,11
    15af24:       e0 c1 42 38     addi    r2,r2,-15904
    15af28:       a6 02 08 7c     mflr    r0
    15af2c:       f0 ff c1 fb     std     r30,-16(r1)
    15af30:       f8 ff e1 fb     std     r31,-8(r1)
  ...

  # perf probe -x /usr/lib64/libc-2.26.so -a inet_pton+0x8
  # perf record -e probe_libc:inet_pton -g ping -6 -c 1 ::1
  # perf script

Before:

  ping  4507 [002] 514985.546540: probe_libc:inet_pton: (7fffa7dbaf28)
              7fffa7dbaf28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
              7fffa7d705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
                 13fb52d70 _init+0xbfc (/usr/bin/ping)
              7fffa7c836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fffa7c83898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

After:

  ping  4507 [002] 514985.546540: probe_libc:inet_pton: (7fffa7dbaf28)
              7fffa7dbaf28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
              7fffa7d6fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
              7fffa7d705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
                 13fb52d70 _init+0xbfc (/usr/bin/ping)
              7fffa7c836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fffa7c83898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

Case 2 - Attaching a probe at _int_malloc+0x180 (binary offset 0x9cf10).
         Return address in still in LR and a new stack frame has already
         been allocated but not used. The caller's caller, i.e. the third
	 entry, is invalid and should be filtered out and not the second
	 one.

  # objdump -d /usr/lib64/libc-2.26.so | less
  ...
  000000000009cd90 <_int_malloc>:
     9cd90:       17 00 4c 3c     addis   r2,r12,23
     9cd94:       70 a3 42 38     addi    r2,r2,-23696
     9cd98:       26 00 80 7d     mfcr    r12
     9cd9c:       f8 ff e1 fb     std     r31,-8(r1)
     9cda0:       17 00 e4 3b     addi    r31,r4,23
     9cda4:       d8 ff 61 fb     std     r27,-40(r1)
     9cda8:       78 23 9b 7c     mr      r27,r4
     9cdac:       1f 00 bf 2b     cmpldi  cr7,r31,31
     9cdb0:       f0 ff c1 fb     std     r30,-16(r1)
     9cdb4:       b0 ff c1 fa     std     r22,-80(r1)
     9cdb8:       78 1b 7e 7c     mr      r30,r3
     9cdbc:       08 00 81 91     stw     r12,8(r1)
     9cdc0:       11 ff 21 f8     stdu    r1,-240(r1)
     9cdc4:       4c 01 9d 41     bgt     cr7,9cf10 <_int_malloc+0x180>
     9cdc8:       20 00 a4 2b     cmpldi  cr7,r4,32
  ...
     9cf08:       00 00 00 60     nop
     9cf0c:       00 00 42 60     ori     r2,r2,0
     9cf10:       e4 06 ff 7b     rldicr  r31,r31,0,59
     9cf14:       40 f8 a4 7f     cmpld   cr7,r4,r31
     9cf18:       68 05 9d 41     bgt     cr7,9d480 <_int_malloc+0x6f0>
  ...
  000000000009e3c0 <tcache_init.part.4>:
  ...
     9e420:       40 02 80 38     li      r4,576
     9e424:       78 fb e3 7f     mr      r3,r31
     9e428:       71 e9 ff 4b     bl      9cd98 <_int_malloc+0x8>
     9e42c:       00 00 a3 2f     cmpdi   cr7,r3,0
     9e430:       78 1b 7e 7c     mr      r30,r3
  ...
  000000000009f7a0 <__libc_malloc>:
  ...
     9f8f8:       00 00 89 2f     cmpwi   cr7,r9,0
     9f8fc:       1c ff 9e 40     bne     cr7,9f818 <__libc_malloc+0x78>
     9f900:       c9 ea ff 4b     bl      9e3c8 <tcache_init.part.4+0x8>
     9f904:       00 00 00 60     nop
     9f908:       e8 90 22 e9     ld      r9,-28440(r2)
  ...

  # perf probe -x /usr/lib64/libc-2.26.so -a _int_malloc+0x180
  # perf record -e probe_libc:_int_malloc -g ./test-malloc
  # perf script

Before:

  test-malloc  6554 [009] 515975.797403: probe_libc:_int_malloc: (7fffa6e6cf10)
              7fffa6e6cf10 _int_malloc+0x180 (/usr/lib64/libc-2.26.so)
              7fffa6dd0000 [unknown] (/usr/lib64/libc-2.26.so)
              7fffa6e6f904 malloc+0x164 (/usr/lib64/libc-2.26.so)
              7fffa6e6f9fc malloc+0x25c (/usr/lib64/libc-2.26.so)
                  100006b4 main+0x38 (/home/testuser/test-malloc)
              7fffa6df36a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fffa6df3898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

After:

  test-malloc  6554 [009] 515975.797403: probe_libc:_int_malloc: (7fffa6e6cf10)
              7fffa6e6cf10 _int_malloc+0x180 (/usr/lib64/libc-2.26.so)
              7fffa6e6e42c tcache_init.part.4+0x6c (/usr/lib64/libc-2.26.so)
              7fffa6e6f904 malloc+0x164 (/usr/lib64/libc-2.26.so)
              7fffa6e6f9fc malloc+0x25c (/usr/lib64/libc-2.26.so)
                  100006b4 main+0x38 (/home/sandipan/test-malloc)
              7fffa6df36a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fffa6df3898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

Fixes: a60335ba3298 ("perf tools powerpc: Adjust callchain based on DWARF debug info")
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
 tools/perf/arch/powerpc/util/skip-callchain-idx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/arch/powerpc/util/skip-callchain-idx.c b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
index ef5d59a5742e..264fc0158100 100644
--- a/tools/perf/arch/powerpc/util/skip-callchain-idx.c
+++ b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
@@ -246,7 +246,7 @@ int arch_skip_callchain_idx(struct thread *thread, struct ip_callchain *chain)
 	if (!chain || chain->nr < 3)
 		return skip_slot;
 
-	ip = chain->ips[2];
+	ip = chain->ips[1];
 
 	thread__find_symbol(thread, PERF_RECORD_MISC_USER, ip, &al);
 
-- 
2.14.4

[PATCH 2/5] perf powerpc: Fix callchain ip filtering when return address is in a register

[Sandipan Das]

For powerpc64, perf will filter out the second entry in the callchain,
i.e. the LR value, if the return address of the function corresponding
to the probed location has already been saved on its caller's stack.

The state of the return address is determined using debug information.
At any point within a function, if the return address is already saved
somewhere, a DWARF expression can tell us about its location. If the
return address in still in LR only, no DWARF expression would exist.

Typically, the instructions in a function's prologue first copy the LR
value to R0 and then pushes R0 on to the stack. If LR has already been
copied to R0 but R0 is yet to be pushed to the stack, we can still get
a DWARF expression that says that the return address is in R0. This is
indicating that getting a DWARF expression for the return address does
not guarantee the fact that it has already been saved on the stack.

This can be observed on a powerpc64le system running Fedora 27 as shown
below.

  # objdump -d /usr/lib64/libc-2.26.so | less
  ...
  000000000015af20 <inet_pton>:
    15af20:       0b 00 4c 3c     addis   r2,r12,11
    15af24:       e0 c1 42 38     addi    r2,r2,-15904
    15af28:       a6 02 08 7c     mflr    r0
    15af2c:       f0 ff c1 fb     std     r30,-16(r1)
    15af30:       f8 ff e1 fb     std     r31,-8(r1)
    15af34:       78 1b 7f 7c     mr      r31,r3
    15af38:       78 23 83 7c     mr      r3,r4
    15af3c:       78 2b be 7c     mr      r30,r5
    15af40:       10 00 01 f8     std     r0,16(r1)
    15af44:       c1 ff 21 f8     stdu    r1,-64(r1)
    15af48:       28 00 81 f8     std     r4,40(r1)
  ...

  # readelf --debug-dump=frames-interp /usr/lib64/libc-2.26.so | less
  ...
  00027024 0000000000000024 00027028 FDE cie=00000000 pc=000000000015af20..000000000015af88
     LOC           CFA      r30   r31   ra
  000000000015af20 r1+0     u     u     u
  000000000015af34 r1+0     c-16  c-8   r0
  000000000015af48 r1+64    c-16  c-8   c+16
  000000000015af5c r1+0     c-16  c-8   c+16
  000000000015af78 r1+0     u     u
  ...

  # perf probe -x /usr/lib64/libc-2.26.so -a inet_pton+0x18
  # perf record -e probe_libc:inet_pton -g ping -6 -c 1 ::1
  # perf script

Before:

  ping  2829 [005] 512917.460174: probe_libc:inet_pton: (7fff7e2baf38)
              7fff7e2baf38 __GI___inet_pton+0x18 (/usr/lib64/libc-2.26.so)
              7fff7e2705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
                 12f152d70 _init+0xbfc (/usr/bin/ping)
              7fff7e1836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fff7e183898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

After:

  ping  2829 [005] 512917.460174: probe_libc:inet_pton: (7fff7e2baf38)
              7fff7e2baf38 __GI___inet_pton+0x18 (/usr/lib64/libc-2.26.so)
              7fff7e26fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
              7fff7e2705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
                 12f152d70 _init+0xbfc (/usr/bin/ping)
              7fff7e1836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fff7e183898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

Reported-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
 tools/perf/arch/powerpc/util/skip-callchain-idx.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/arch/powerpc/util/skip-callchain-idx.c b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
index 264fc0158100..7c6eeb4633fe 100644
--- a/tools/perf/arch/powerpc/util/skip-callchain-idx.c
+++ b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
@@ -58,9 +58,13 @@ static int check_return_reg(int ra_regno, Dwarf_Frame *frame)
 	}
 
 	/*
-	 * Check if return address is on the stack.
+	 * Check if return address is on the stack. If return address
+	 * is in a register (typically R0), it is yet to be saved on
+	 * the stack.
 	 */
-	if (nops != 0 || ops != NULL)
+	if ((nops != 0 || ops != NULL) &&
+		!(nops == 1 && ops[0].atom == DW_OP_regx &&
+			ops[0].number2 == 0 && ops[0].offset == 0))
 		return 0;
 
 	/*
-- 
2.14.4

[PATCH 3/5] perf tests: Fix record+probe_libc_inet_pton.sh for powerpc64

[Sandipan Das]

For powerpc64, this test currently fails due to a mismatch in
the expected output.

This can be observed on a powerpc64le system running Fedora 27
as shown below.

  # perf test -v "probe libc's inet_pton & backtrace it with ping"

Before:

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 23948
  ping 23965 [003] 71136.075084: probe_libc:inet_pton: (7fff996aaf28)
  7fff996aaf28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
  7fff9965fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
  FAIL: expected backtrace entry 2 "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\(/usr/lib64/libc-2.26.so\)$" got "7fff9965fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)"
  test child finished with -1
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: FAILED!

After:

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 24638
  ping 24655 [001] 71208.525396: probe_libc:inet_pton: (7fffa245af28)
  7fffa245af28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
  7fffa240fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
  7fffa24105b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
  138d52d70 main+0x3e0 (/usr/bin/ping)
  test child finished with 0
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: Ok

Fixes: e07d585e2454 ("perf tests: Switch trace+probe_libc_inet_pton to use record")
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
 tools/perf/tests/shell/record+probe_libc_inet_pton.sh | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
index 94e513e62b34..1220e5e052bb 100755
--- a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
+++ b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
@@ -26,6 +26,12 @@ trace_libc_inet_pton_backtrace() {
 		echo "(__GI_)?getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected
 		echo "main\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected
 		;;
+	ppc64|ppc64le)
+		eventattr='max-stack=4'
+		echo "gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected
+		echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected
+		echo ".*\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected
+		;;
 	*)
 		eventattr='max-stack=3'
 		echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected
-- 
2.14.4

[PATCH 4/5] perf tests: Fix record+probe_libc_inet_pton.sh to ensure cleanups

[Sandipan Das]

If there is a mismatch in the perf script output, this test fails
and exits before the event and temporary files created during its
execution are cleaned up.

This can be observed on a powerpc64 system running Fedora 27 as
shown below.

  # perf test -v "probe libc's inet_pton & backtrace it with ping"

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 18655
  ping 18674 [013] 24511.496995: probe_libc:inet_pton: (7fffa6b423b0)
  7fffa6b423b0 __GI___inet_pton+0x0 (/usr/lib64/power8/libc-2.26.so)
  7fffa6af90dc gaih_inet.constprop.7+0xf4c (/usr/lib64/power8/libc-2.26.so)
  FAIL: expected backtrace entry "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\(/usr/lib64/power8/libc-2.26.so\)$" got "7fffa6af90dc gaih_inet.constprop.7+0xf4c (/usr/lib64/power8/libc-2.26.so)"
  test child finished with -1
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: FAILED!

  # ls /tmp/expected.* /tmp/perf.data.* /tmp/perf.script.*

  /tmp/expected.u31  /tmp/perf.data.Pki  /tmp/perf.script.Bhs

  # perf probe --list

    probe_libc:inet_pton (on __inet_pton@resolv/inet_pton.c in /usr/lib64/power8/libc-2.26.so)

Cleanup of the event and the temporary files are now ensured by
allowing the cleanup code to be executed even if the lines from
the backtrace do not match their expected patterns instead of
simply exiting from the point of failure.

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
 tools/perf/tests/shell/record+probe_libc_inet_pton.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
index 1220e5e052bb..0502a9e04c79 100755
--- a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
+++ b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
@@ -52,7 +52,7 @@ trace_libc_inet_pton_backtrace() {
 		echo "$line" | egrep -q "$pattern"
 		if [ $? -ne 0 ] ; then
 			printf "FAIL: expected backtrace entry \"%s\" got \"%s\"\n" "$pattern" "$line"
-			exit 1
+			return 1
 		fi
 	done
 
-- 
2.14.4

[PATCH 5/5] perf tests: Fix record+probe_libc_inet_pton.sh when event exists

[Sandipan Das]

If the event 'probe_libc:inet_pton' already exists, this test
fails and deletes the existing event before exiting. This will
then pass for any subsequent executions.

Instead of skipping to deleting the existing event because of
failing to add a new event, a duplicate event is now created
and the script continues with the usual checks. Only the new
duplicate event that is created at the beginning of the test
is deleted as a part of the cleanups in the end. All existing
events remain as it is.

This can be observed on a powerpc64 system running Fedora 27 as
shown below.

  # perf probe -x /usr/lib64/power8/libc-2.26.so -a inet_pton

  Added new event:
    probe_libc:inet_pton (on inet_pton in /usr/lib64/power8/libc-2.26.so)

Before:

  # perf test -v "probe libc's inet_pton & backtrace it with ping"

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 21302
  test child finished with -1
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: FAILED!

  # perf probe --list

After:

  # perf test -v "probe libc's inet_pton & backtrace it with ping"

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 21490
  ping 21513 [035] 39357.565561: probe_libc:inet_pton_1: (7fffa4c623b0)
  7fffa4c623b0 __GI___inet_pton+0x0 (/usr/lib64/power8/libc-2.26.so)
  7fffa4c190dc gaih_inet.constprop.7+0xf4c (/usr/lib64/power8/libc-2.26.so)
  7fffa4c19c4c getaddrinfo+0x15c (/usr/lib64/power8/libc-2.26.so)
  111d93c20 main+0x3e0 (/usr/bin/ping)
  test child finished with 0
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: Ok

  # perf probe --list

    probe_libc:inet_pton (on __inet_pton@resolv/inet_pton.c in /usr/lib64/power8/libc-2.26.so)

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
 .../tests/shell/record+probe_libc_inet_pton.sh     | 28 ++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
index 0502a9e04c79..3013ac8f83d0 100755
--- a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
+++ b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
@@ -13,11 +13,24 @@
 libc=$(grep -w libc /proc/self/maps | head -1 | sed -r 's/.*[[:space:]](\/.*)/\1/g')
 nm -Dg $libc 2>/dev/null | fgrep -q inet_pton || exit 254
 
+event_pattern='probe_libc:inet_pton(\_[[:digit:]]+)?'
+
+add_libc_inet_pton_event() {
+
+	event_name=$(perf probe -f -x $libc -a inet_pton 2>&1 | tail -n +2 | head -n -5 | \
+			grep -P -o "$event_pattern(?=[[:space:]]\(on inet_pton in $libc\))")
+
+	if [ $? -ne 0 -o -z "$event_name" ] ; then
+		printf "FAIL: could not add event\n"
+		return 1
+	fi
+}
+
 trace_libc_inet_pton_backtrace() {
 
 	expected=`mktemp -u /tmp/expected.XXX`
 
-	echo "ping[][0-9 \.:]+probe_libc:inet_pton: \([[:xdigit:]]+\)" > $expected
+	echo "ping[][0-9 \.:]+$event_name: \([[:xdigit:]]+\)" > $expected
 	echo ".*inet_pton\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected
 	case "$(uname -m)" in
 	s390x)
@@ -41,7 +54,7 @@ trace_libc_inet_pton_backtrace() {
 
 	perf_data=`mktemp -u /tmp/perf.data.XXX`
 	perf_script=`mktemp -u /tmp/perf.script.XXX`
-	perf record -e probe_libc:inet_pton/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1
+	perf record -e $event_name/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1
 	perf script -i $perf_data > $perf_script
 
 	exec 3<$perf_script
@@ -62,13 +75,20 @@ trace_libc_inet_pton_backtrace() {
 	# even if the perf script output does not match.
 }
 
+delete_libc_inet_pton_event() {
+
+	if [ -n "$event_name" ] ; then
+		perf probe -q -d $event_name
+	fi
+}
+
 # Check for IPv6 interface existence
 ip a sh lo | fgrep -q inet6 || exit 2
 
 skip_if_no_perf_probe && \
-perf probe -q $libc inet_pton && \
+add_libc_inet_pton_event && \
 trace_libc_inet_pton_backtrace
 err=$?
 rm -f ${perf_data} ${perf_script} ${expected}
-perf probe -q -d probe_libc:inet_pton
+delete_libc_inet_pton_event
 exit $err
-- 
2.14.4

Re: [PATCH 0/5] perf: Fixes for callchain ip handling and related tests

[Arnaldo Carvalho de Melo]

Em Tue, Jul 10, 2018 at 07:28:12PM +0530, Sandipan Das escreveu:
> The first two patches fix the callchain ip filtering mechanism for
> powerpc from skipping entries unecessarily by checking the status of
> a function's return address in the stack.
> 
> The third patch fixes a shell test that fails on powerpc due to a
> mismatch in the expected perf script output.
> 
> The fourth and fifth patches are generic fixes for the same shell
> test.
> 
> --
> 
> Hi Arnaldo,
> 
> This series has fixes for the inet_pton shell test and depends
> on the following patches from Kim Phillips:

I found the tip-bot messages telling me those were applied already,
merged your patches and pushed them to acme/perf/core, please check that
everything is ok. Ping me if there are more outstanding patches, I'm
back from vacation.

[tip:perf/core] perf powerpc: Fix callchain ip filtering

[tip-bot for Sandipan Das]

Commit-ID:  c715fcfda5a08edabaa15508742be926b7ee51db
Gitweb:     https://git.kernel.org/tip/c715fcfda5a08edabaa15508742be926b7ee51db
Author:     Sandipan Das <sandipan@linux.ibm.com>
AuthorDate: Tue, 10 Jul 2018 19:28:13 +0530
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 24 Jul 2018 14:50:10 -0300

perf powerpc: Fix callchain ip filtering

For powerpc64, redundant entries in the callchain are filtered out by
determining the state of the return address and the stack frame using
DWARF debug information.

For making these filtering decisions we must analyze the debug
information for the location corresponding to the program counter value,
i.e. the first entry in the callchain, and not the LR value; otherwise,
perf may filter out either the second or the third entry in the
callchain incorrectly.

This can be observed on a powerpc64le system running Fedora 27 as shown
below.

Case 1 - Attaching a probe at inet_pton+0x8 (binary offset 0x15af28).
         Return address is still in LR and a new stack frame is not yet
         allocated. The LR value, i.e. the second entry, should not be
	 filtered out.

  # objdump -d /usr/lib64/libc-2.26.so | less
  ...
  000000000010eb10 <gaih_inet.constprop.7>:
  ...
    10fa48:       78 bb e4 7e     mr      r4,r23
    10fa4c:       0a 00 60 38     li      r3,10
    10fa50:       d9 b4 04 48     bl      15af28 <inet_pton+0x8>
    10fa54:       00 00 00 60     nop
    10fa58:       ac f4 ff 4b     b       10ef04 <gaih_inet.constprop.7+0x3f4>
  ...
  0000000000110450 <getaddrinfo>:
  ...
    1105a8:       54 00 ff 38     addi    r7,r31,84
    1105ac:       58 00 df 38     addi    r6,r31,88
    1105b0:       69 e5 ff 4b     bl      10eb18 <gaih_inet.constprop.7+0x8>
    1105b4:       78 1b 71 7c     mr      r17,r3
    1105b8:       50 01 7f e8     ld      r3,336(r31)
  ...
  000000000015af20 <inet_pton>:
    15af20:       0b 00 4c 3c     addis   r2,r12,11
    15af24:       e0 c1 42 38     addi    r2,r2,-15904
    15af28:       a6 02 08 7c     mflr    r0
    15af2c:       f0 ff c1 fb     std     r30,-16(r1)
    15af30:       f8 ff e1 fb     std     r31,-8(r1)
  ...

  # perf probe -x /usr/lib64/libc-2.26.so -a inet_pton+0x8
  # perf record -e probe_libc:inet_pton -g ping -6 -c 1 ::1
  # perf script

Before:

  ping  4507 [002] 514985.546540: probe_libc:inet_pton: (7fffa7dbaf28)
              7fffa7dbaf28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
              7fffa7d705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
                 13fb52d70 _init+0xbfc (/usr/bin/ping)
              7fffa7c836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fffa7c83898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

After:

  ping  4507 [002] 514985.546540: probe_libc:inet_pton: (7fffa7dbaf28)
              7fffa7dbaf28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
              7fffa7d6fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
              7fffa7d705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
                 13fb52d70 _init+0xbfc (/usr/bin/ping)
              7fffa7c836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fffa7c83898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

Case 2 - Attaching a probe at _int_malloc+0x180 (binary offset 0x9cf10).
         Return address in still in LR and a new stack frame has already
         been allocated but not used. The caller's caller, i.e. the third
	 entry, is invalid and should be filtered out and not the second
	 one.

  # objdump -d /usr/lib64/libc-2.26.so | less
  ...
  000000000009cd90 <_int_malloc>:
     9cd90:       17 00 4c 3c     addis   r2,r12,23
     9cd94:       70 a3 42 38     addi    r2,r2,-23696
     9cd98:       26 00 80 7d     mfcr    r12
     9cd9c:       f8 ff e1 fb     std     r31,-8(r1)
     9cda0:       17 00 e4 3b     addi    r31,r4,23
     9cda4:       d8 ff 61 fb     std     r27,-40(r1)
     9cda8:       78 23 9b 7c     mr      r27,r4
     9cdac:       1f 00 bf 2b     cmpldi  cr7,r31,31
     9cdb0:       f0 ff c1 fb     std     r30,-16(r1)
     9cdb4:       b0 ff c1 fa     std     r22,-80(r1)
     9cdb8:       78 1b 7e 7c     mr      r30,r3
     9cdbc:       08 00 81 91     stw     r12,8(r1)
     9cdc0:       11 ff 21 f8     stdu    r1,-240(r1)
     9cdc4:       4c 01 9d 41     bgt     cr7,9cf10 <_int_malloc+0x180>
     9cdc8:       20 00 a4 2b     cmpldi  cr7,r4,32
  ...
     9cf08:       00 00 00 60     nop
     9cf0c:       00 00 42 60     ori     r2,r2,0
     9cf10:       e4 06 ff 7b     rldicr  r31,r31,0,59
     9cf14:       40 f8 a4 7f     cmpld   cr7,r4,r31
     9cf18:       68 05 9d 41     bgt     cr7,9d480 <_int_malloc+0x6f0>
  ...
  000000000009e3c0 <tcache_init.part.4>:
  ...
     9e420:       40 02 80 38     li      r4,576
     9e424:       78 fb e3 7f     mr      r3,r31
     9e428:       71 e9 ff 4b     bl      9cd98 <_int_malloc+0x8>
     9e42c:       00 00 a3 2f     cmpdi   cr7,r3,0
     9e430:       78 1b 7e 7c     mr      r30,r3
  ...
  000000000009f7a0 <__libc_malloc>:
  ...
     9f8f8:       00 00 89 2f     cmpwi   cr7,r9,0
     9f8fc:       1c ff 9e 40     bne     cr7,9f818 <__libc_malloc+0x78>
     9f900:       c9 ea ff 4b     bl      9e3c8 <tcache_init.part.4+0x8>
     9f904:       00 00 00 60     nop
     9f908:       e8 90 22 e9     ld      r9,-28440(r2)
  ...

  # perf probe -x /usr/lib64/libc-2.26.so -a _int_malloc+0x180
  # perf record -e probe_libc:_int_malloc -g ./test-malloc
  # perf script

Before:

  test-malloc  6554 [009] 515975.797403: probe_libc:_int_malloc: (7fffa6e6cf10)
              7fffa6e6cf10 _int_malloc+0x180 (/usr/lib64/libc-2.26.so)
              7fffa6dd0000 [unknown] (/usr/lib64/libc-2.26.so)
              7fffa6e6f904 malloc+0x164 (/usr/lib64/libc-2.26.so)
              7fffa6e6f9fc malloc+0x25c (/usr/lib64/libc-2.26.so)
                  100006b4 main+0x38 (/home/testuser/test-malloc)
              7fffa6df36a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fffa6df3898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

After:

  test-malloc  6554 [009] 515975.797403: probe_libc:_int_malloc: (7fffa6e6cf10)
              7fffa6e6cf10 _int_malloc+0x180 (/usr/lib64/libc-2.26.so)
              7fffa6e6e42c tcache_init.part.4+0x6c (/usr/lib64/libc-2.26.so)
              7fffa6e6f904 malloc+0x164 (/usr/lib64/libc-2.26.so)
              7fffa6e6f9fc malloc+0x25c (/usr/lib64/libc-2.26.so)
                  100006b4 main+0x38 (/home/sandipan/test-malloc)
              7fffa6df36a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fffa6df3898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Maynard Johnson <maynard@us.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Fixes: a60335ba3298 ("perf tools powerpc: Adjust callchain based on DWARF debug info")
Link: http://lkml.kernel.org/r/24bb726d91ed173aebc972ec3f41a2ef2249434e.1530724939.git.sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/arch/powerpc/util/skip-callchain-idx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/arch/powerpc/util/skip-callchain-idx.c b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
index ef5d59a5742e..264fc0158100 100644
--- a/tools/perf/arch/powerpc/util/skip-callchain-idx.c
+++ b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
@@ -246,7 +246,7 @@ int arch_skip_callchain_idx(struct thread *thread, struct ip_callchain *chain)
 	if (!chain || chain->nr < 3)
 		return skip_slot;
 
-	ip = chain->ips[2];
+	ip = chain->ips[1];
 
 	thread__find_symbol(thread, PERF_RECORD_MISC_USER, ip, &al);
 

[tip:perf/core] perf powerpc: Fix callchain ip filtering when return address is in a register

[tip-bot for Sandipan Das]

Commit-ID:  9068533e4f470daf2b0f29c71d865990acd8826e
Gitweb:     https://git.kernel.org/tip/9068533e4f470daf2b0f29c71d865990acd8826e
Author:     Sandipan Das <sandipan@linux.ibm.com>
AuthorDate: Tue, 10 Jul 2018 19:28:14 +0530
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 24 Jul 2018 14:50:44 -0300

perf powerpc: Fix callchain ip filtering when return address is in a register

For powerpc64, perf will filter out the second entry in the callchain,
i.e. the LR value, if the return address of the function corresponding
to the probed location has already been saved on its caller's stack.

The state of the return address is determined using debug information.
At any point within a function, if the return address is already saved
somewhere, a DWARF expression can tell us about its location. If the
return address in still in LR only, no DWARF expression would exist.

Typically, the instructions in a function's prologue first copy the LR
value to R0 and then pushes R0 on to the stack. If LR has already been
copied to R0 but R0 is yet to be pushed to the stack, we can still get a
DWARF expression that says that the return address is in R0. This is
indicating that getting a DWARF expression for the return address does
not guarantee the fact that it has already been saved on the stack.

This can be observed on a powerpc64le system running Fedora 27 as shown
below.

  # objdump -d /usr/lib64/libc-2.26.so | less
  ...
  000000000015af20 <inet_pton>:
    15af20:       0b 00 4c 3c     addis   r2,r12,11
    15af24:       e0 c1 42 38     addi    r2,r2,-15904
    15af28:       a6 02 08 7c     mflr    r0
    15af2c:       f0 ff c1 fb     std     r30,-16(r1)
    15af30:       f8 ff e1 fb     std     r31,-8(r1)
    15af34:       78 1b 7f 7c     mr      r31,r3
    15af38:       78 23 83 7c     mr      r3,r4
    15af3c:       78 2b be 7c     mr      r30,r5
    15af40:       10 00 01 f8     std     r0,16(r1)
    15af44:       c1 ff 21 f8     stdu    r1,-64(r1)
    15af48:       28 00 81 f8     std     r4,40(r1)
  ...

  # readelf --debug-dump=frames-interp /usr/lib64/libc-2.26.so | less
  ...
  00027024 0000000000000024 00027028 FDE cie=00000000 pc=000000000015af20..000000000015af88
     LOC           CFA      r30   r31   ra
  000000000015af20 r1+0     u     u     u
  000000000015af34 r1+0     c-16  c-8   r0
  000000000015af48 r1+64    c-16  c-8   c+16
  000000000015af5c r1+0     c-16  c-8   c+16
  000000000015af78 r1+0     u     u
  ...

  # perf probe -x /usr/lib64/libc-2.26.so -a inet_pton+0x18
  # perf record -e probe_libc:inet_pton -g ping -6 -c 1 ::1
  # perf script

Before:

  ping  2829 [005] 512917.460174: probe_libc:inet_pton: (7fff7e2baf38)
              7fff7e2baf38 __GI___inet_pton+0x18 (/usr/lib64/libc-2.26.so)
              7fff7e2705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
                 12f152d70 _init+0xbfc (/usr/bin/ping)
              7fff7e1836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fff7e183898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

After:

  ping  2829 [005] 512917.460174: probe_libc:inet_pton: (7fff7e2baf38)
              7fff7e2baf38 __GI___inet_pton+0x18 (/usr/lib64/libc-2.26.so)
              7fff7e26fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
              7fff7e2705b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
                 12f152d70 _init+0xbfc (/usr/bin/ping)
              7fff7e1836a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fff7e183898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])

Reported-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Maynard Johnson <maynard@us.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/66e848a7bdf2d43b39210a705ff6d828a0865661.1530724939.git.sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/arch/powerpc/util/skip-callchain-idx.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/arch/powerpc/util/skip-callchain-idx.c b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
index 264fc0158100..7c6eeb4633fe 100644
--- a/tools/perf/arch/powerpc/util/skip-callchain-idx.c
+++ b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
@@ -58,9 +58,13 @@ static int check_return_reg(int ra_regno, Dwarf_Frame *frame)
 	}
 
 	/*
-	 * Check if return address is on the stack.
+	 * Check if return address is on the stack. If return address
+	 * is in a register (typically R0), it is yet to be saved on
+	 * the stack.
 	 */
-	if (nops != 0 || ops != NULL)
+	if ((nops != 0 || ops != NULL) &&
+		!(nops == 1 && ops[0].atom == DW_OP_regx &&
+			ops[0].number2 == 0 && ops[0].offset == 0))
 		return 0;
 
 	/*

[tip:perf/core] perf tests: Fix record+probe_libc_inet_pton.sh for powerpc64

[tip-bot for Sandipan Das]

Commit-ID:  3eae52f842329a95f8549124079518231c0daba8
Gitweb:     https://git.kernel.org/tip/3eae52f842329a95f8549124079518231c0daba8
Author:     Sandipan Das <sandipan@linux.ibm.com>
AuthorDate: Tue, 10 Jul 2018 19:28:15 +0530
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 24 Jul 2018 14:51:37 -0300

perf tests: Fix record+probe_libc_inet_pton.sh for powerpc64

For powerpc64, this test currently fails due to a mismatch in the
expected output.

This can be observed on a powerpc64le system running Fedora 27 as shown
below.

  # perf test -v "probe libc's inet_pton & backtrace it with ping"

Before:

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 23948
  ping 23965 [003] 71136.075084: probe_libc:inet_pton: (7fff996aaf28)
  7fff996aaf28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
  7fff9965fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
  FAIL: expected backtrace entry 2 "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\(/usr/lib64/libc-2.26.so\)$" got "7fff9965fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)"
  test child finished with -1
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: FAILED!

After:

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 24638
  ping 24655 [001] 71208.525396: probe_libc:inet_pton: (7fffa245af28)
  7fffa245af28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
  7fffa240fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
  7fffa24105b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
  138d52d70 main+0x3e0 (/usr/bin/ping)
  test child finished with 0
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: Ok

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Maynard Johnson <maynard@us.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Fixes: e07d585e2454 ("perf tests: Switch trace+probe_libc_inet_pton to use record")
Link: http://lkml.kernel.org/r/49621ec5f37109f0655e5a8c32287ad68d85a1e5.1530724939.git.sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/shell/record+probe_libc_inet_pton.sh | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
index 94e513e62b34..1220e5e052bb 100755
--- a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
+++ b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
@@ -26,6 +26,12 @@ trace_libc_inet_pton_backtrace() {
 		echo "(__GI_)?getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected
 		echo "main\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected
 		;;
+	ppc64|ppc64le)
+		eventattr='max-stack=4'
+		echo "gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected
+		echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected
+		echo ".*\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected
+		;;
 	*)
 		eventattr='max-stack=3'
 		echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected

[tip:perf/core] perf tests: Fix record+probe_libc_inet_pton.sh to ensure cleanups

[tip-bot for Sandipan Das]

Commit-ID:  83e3b6d73e66a10088f362b08b99c36fec3a14e7
Gitweb:     https://git.kernel.org/tip/83e3b6d73e66a10088f362b08b99c36fec3a14e7
Author:     Sandipan Das <sandipan@linux.ibm.com>
AuthorDate: Tue, 10 Jul 2018 19:28:16 +0530
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 24 Jul 2018 14:52:09 -0300

perf tests: Fix record+probe_libc_inet_pton.sh to ensure cleanups

If there is a mismatch in the perf script output, this test fails and
exits before the event and temporary files created during its execution
are cleaned up.

This can be observed on a powerpc64 system running Fedora 27 as shown
below.

  # perf test -v "probe libc's inet_pton & backtrace it with ping"

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 18655
  ping 18674 [013] 24511.496995: probe_libc:inet_pton: (7fffa6b423b0)
  7fffa6b423b0 __GI___inet_pton+0x0 (/usr/lib64/power8/libc-2.26.so)
  7fffa6af90dc gaih_inet.constprop.7+0xf4c (/usr/lib64/power8/libc-2.26.so)
  FAIL: expected backtrace entry "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\(/usr/lib64/power8/libc-2.26.so\)$" got "7fffa6af90dc gaih_inet.constprop.7+0xf4c (/usr/lib64/power8/libc-2.26.so)"
  test child finished with -1
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: FAILED!

  # ls /tmp/expected.* /tmp/perf.data.* /tmp/perf.script.*

  /tmp/expected.u31  /tmp/perf.data.Pki  /tmp/perf.script.Bhs

  # perf probe --list

    probe_libc:inet_pton (on __inet_pton@resolv/inet_pton.c in /usr/lib64/power8/libc-2.26.so)

Cleanup of the event and the temporary files are now ensured by allowing
the cleanup code to be executed even if the lines from the backtrace do
not match their expected patterns instead of simply exiting from the
point of failure.

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/ce9fb091dd3028fba8749a1a267cfbcb264bbfb1.1530724939.git.sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/shell/record+probe_libc_inet_pton.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
index 1220e5e052bb..0502a9e04c79 100755
--- a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
+++ b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
@@ -52,7 +52,7 @@ trace_libc_inet_pton_backtrace() {
 		echo "$line" | egrep -q "$pattern"
 		if [ $? -ne 0 ] ; then
 			printf "FAIL: expected backtrace entry \"%s\" got \"%s\"\n" "$pattern" "$line"
-			exit 1
+			return 1
 		fi
 	done
 

[tip:perf/core] perf tests: Fix record+probe_libc_inet_pton.sh when event exists

[tip-bot for Sandipan Das]

Commit-ID:  60089e42d38438772e2f83334e3e5b7497009366
Gitweb:     https://git.kernel.org/tip/60089e42d38438772e2f83334e3e5b7497009366
Author:     Sandipan Das <sandipan@linux.ibm.com>
AuthorDate: Tue, 10 Jul 2018 19:28:17 +0530
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 24 Jul 2018 14:52:19 -0300

perf tests: Fix record+probe_libc_inet_pton.sh when event exists

If the event 'probe_libc:inet_pton' already exists, this test fails and
deletes the existing event before exiting. This will then pass for any
subsequent executions.

Instead of skipping to deleting the existing event because of failing to
add a new event, a duplicate event is now created and the script
continues with the usual checks. Only the new duplicate event that is
created at the beginning of the test is deleted as a part of the
cleanups in the end. All existing events remain as it is.

This can be observed on a powerpc64 system running Fedora 27 as shown
below.

  # perf probe -x /usr/lib64/power8/libc-2.26.so -a inet_pton

  Added new event:
    probe_libc:inet_pton (on inet_pton in /usr/lib64/power8/libc-2.26.so)

Before:

  # perf test -v "probe libc's inet_pton & backtrace it with ping"

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 21302
  test child finished with -1
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: FAILED!

  # perf probe --list

After:

  # perf test -v "probe libc's inet_pton & backtrace it with ping"

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 21490
  ping 21513 [035] 39357.565561: probe_libc:inet_pton_1: (7fffa4c623b0)
  7fffa4c623b0 __GI___inet_pton+0x0 (/usr/lib64/power8/libc-2.26.so)
  7fffa4c190dc gaih_inet.constprop.7+0xf4c (/usr/lib64/power8/libc-2.26.so)
  7fffa4c19c4c getaddrinfo+0x15c (/usr/lib64/power8/libc-2.26.so)
  111d93c20 main+0x3e0 (/usr/bin/ping)
  test child finished with 0
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: Ok

  # perf probe --list

    probe_libc:inet_pton (on __inet_pton@resolv/inet_pton.c in /usr/lib64/power8/libc-2.26.so)

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/e11fecff96e6cf4c65cdbd9012463513d7b8356c.1530724939.git.sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 .../tests/shell/record+probe_libc_inet_pton.sh     | 28 ++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
index 0502a9e04c79..3013ac8f83d0 100755
--- a/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
+++ b/tools/perf/tests/shell/record+probe_libc_inet_pton.sh
@@ -13,11 +13,24 @@
 libc=$(grep -w libc /proc/self/maps | head -1 | sed -r 's/.*[[:space:]](\/.*)/\1/g')
 nm -Dg $libc 2>/dev/null | fgrep -q inet_pton || exit 254
 
+event_pattern='probe_libc:inet_pton(\_[[:digit:]]+)?'
+
+add_libc_inet_pton_event() {
+
+	event_name=$(perf probe -f -x $libc -a inet_pton 2>&1 | tail -n +2 | head -n -5 | \
+			grep -P -o "$event_pattern(?=[[:space:]]\(on inet_pton in $libc\))")
+
+	if [ $? -ne 0 -o -z "$event_name" ] ; then
+		printf "FAIL: could not add event\n"
+		return 1
+	fi
+}
+
 trace_libc_inet_pton_backtrace() {
 
 	expected=`mktemp -u /tmp/expected.XXX`
 
-	echo "ping[][0-9 \.:]+probe_libc:inet_pton: \([[:xdigit:]]+\)" > $expected
+	echo "ping[][0-9 \.:]+$event_name: \([[:xdigit:]]+\)" > $expected
 	echo ".*inet_pton\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected
 	case "$(uname -m)" in
 	s390x)
@@ -41,7 +54,7 @@ trace_libc_inet_pton_backtrace() {
 
 	perf_data=`mktemp -u /tmp/perf.data.XXX`
 	perf_script=`mktemp -u /tmp/perf.script.XXX`
-	perf record -e probe_libc:inet_pton/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1
+	perf record -e $event_name/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1
 	perf script -i $perf_data > $perf_script
 
 	exec 3<$perf_script
@@ -62,13 +75,20 @@ trace_libc_inet_pton_backtrace() {
 	# even if the perf script output does not match.
 }
 
+delete_libc_inet_pton_event() {
+
+	if [ -n "$event_name" ] ; then
+		perf probe -q -d $event_name
+	fi
+}
+
 # Check for IPv6 interface existence
 ip a sh lo | fgrep -q inet6 || exit 2
 
 skip_if_no_perf_probe && \
-perf probe -q $libc inet_pton && \
+add_libc_inet_pton_event && \
 trace_libc_inet_pton_backtrace
 err=$?
 rm -f ${perf_data} ${perf_script} ${expected}
-perf probe -q -d probe_libc:inet_pton
+delete_libc_inet_pton_event
 exit $err