kernel.git/tools/perf/arch/powerpc, branch linux-4.4.y

perf probe powerpc: Ignore SyS symbols irrespective of endianness

2018-10-10T06:52:12Z

[ Upstream commit fa694160cca6dbba17c57dc7efec5f93feaf8795 ] This makes sure that the SyS symbols are ignored for any powerpc system, not just the big endian ones. Reported-by: Naveen N. Rao Signed-off-by: Sandipan Das Reviewed-by: Kamalesh Babulal Acked-by: Naveen N. Rao Cc: Jiri Olsa Cc: Ravi Bangoria Fixes: fb6d59423115 ("perf probe ppc: Use the right prefix when ignoring SyS symbols on ppc") Link: http://lkml.kernel.org/r/20180828090848.1914-1-sandipan@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

perf powerpc: Fix callchain ip filtering

2018-09-26T06:35:06Z

[ Upstream commit c715fcfda5a08edabaa15508742be926b7ee51db ] 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 : ... 10fa48: 78 bb e4 7e mr r4,r23 10fa4c: 0a 00 60 38 li r3,10 10fa50: d9 b4 04 48 bl 15af28 10fa54: 00 00 00 60 nop 10fa58: ac f4 ff 4b b 10ef04 ... 0000000000110450 : ... 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 1105b4: 78 1b 71 7c mr r17,r3 1105b8: 50 01 7f e8 ld r3,336(r31) ... 000000000015af20 : 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 : ... 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 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 Cc: Jiri Olsa Cc: Maynard Johnson Cc: Naveen N. Rao Cc: Ravi Bangoria Cc: Sukadev Bhattiprolu 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 Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

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

2018-09-26T06:35:05Z

[ Upstream commit 9068533e4f470daf2b0f29c71d865990acd8826e ] 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 : 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 Signed-off-by: Sandipan Das Cc: Jiri Olsa Cc: Maynard Johnson Cc: Naveen N. Rao Cc: Ravi Bangoria Cc: Sukadev Bhattiprolu Link: http://lkml.kernel.org/r/66e848a7bdf2d43b39210a705ff6d828a0865661.1530724939.git.sandipan@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

perf report powerpc: Fix crash if callchain is empty

2018-08-24T11:26:56Z

[ Upstream commit 143c99f6ac6812d23254e80844d6e34be897d3e1 ] For some cases, the callchain provided by the kernel may be empty. So, the callchain ip filtering code will cause a crash if we do not check whether the struct ip_callchain pointer is NULL before accessing any members. This can be observed on a powerpc64le system running Fedora 27 as shown below. # perf record -b -e cycles:u ls Before: # perf report --branch-history perf: Segmentation fault -------- backtrace -------- perf[0x1027615c] linux-vdso64.so.1(__kernel_sigtramp_rt64+0x0)[0x7fff856304d8] perf(arch_skip_callchain_idx+0x44)[0x10257c58] perf[0x1017f2e4] perf(thread__resolve_callchain+0x124)[0x1017ff5c] perf(sample__resolve_callchain+0xf0)[0x10172788] ... After: # perf report --branch-history Samples: 25 of event 'cycles:u', Event count (approx.): 2306870 Overhead Source:Line Symbol Shared Object + 11.60% _init+35736 [.] _init ls + 9.84% strcoll_l.c:137 [.] __strcoll_l libc-2.26.so + 9.16% memcpy.S:175 [.] __memcpy_power7 libc-2.26.so + 9.01% gconv_charset.h:54 [.] _nl_find_locale libc-2.26.so + 8.87% dl-addr.c:52 [.] _dl_addr libc-2.26.so + 8.83% _init+236 [.] _init ls ... Reported-by: Ravi Bangoria Signed-off-by: Sandipan Das Acked-by: Ravi Bangoria Cc: Jiri Olsa Cc: Naveen N. Rao Cc: Sukadev Bhattiprolu Link: http://lkml.kernel.org/r/20180611104049.11048-1-sandipan@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

perf probe ppc64le: Fixup function entry if using kallsyms lookup

2015-05-04T15:43:47Z

On powerpc ABIv2, if no debug-info is found and we use kallsyms, we need to fixup the function entry to point to the local entry point. Use offset of 8 since current toolchains always generate 2 instructions (8 bytes). Signed-off-by: Naveen N. Rao Reviewed-by: Srikar Dronamraju Cc: Ananth N Mavinakayanahalli Cc: Masami Hiramatsu Cc: Michael Ellerman Cc: Sukadev Bhattiprolu Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/92253021e77a104b23b615c8c23bf9501dfe60bf.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf probe ppc64le: Prefer symbol table lookup over DWARF

2015-05-04T15:43:46Z

Use symbol table lookups by default if DWARF is not necessary, since powerpc ABIv2 encodes local entry points in the symbol table and the function entry address in DWARF may not be appropriate for kprobes, as described here: https://sourceware.org/bugzilla/show_bug.cgi?id=17638 "The DWARF address ranges deliberately include the *whole* function, both global and local entry points." ... "If you want to set probes on a local entry point, you should look up the symbol in the main symbol table (not DWARF), and check the st_other bits; they will indicate whether the function has a local entry point, and what its offset from the global entry point is. Note that GDB does the same when setting a breakpoint on a function entry." Signed-off-by: Naveen N. Rao Reviewed-by: Srikar Dronamraju Cc: Ananth N Mavinakayanahalli Cc: Masami Hiramatsu Cc: Michael Ellerman Cc: Sukadev Bhattiprolu Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/88a10e22f4aaba2aef812824ca4b10d7beeea012.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf probe ppc64le: Fix ppc64 ABIv2 symbol decoding

2015-05-04T15:43:45Z

ppc64 ELF ABIv2 has a Global Entry Point (GEP) and a Local Entry Point (LEP). For purposes of probing, we need the LEP - the offset to which is encoded in st_other. Signed-off-by: Ananth N Mavinakayanahalli Reviewed-by: Srikar Dronamraju Cc: Masami Hiramatsu Cc: Michael Ellerman Cc: Sukadev Bhattiprolu Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/ab9cc5e2b9de4cbaaf50f6ef2346a6a81100bad1.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Naveen N. Rao Signed-off-by: Arnaldo Carvalho de Melo

perf probe ppc: Enable matching against dot symbols automatically

2015-05-04T15:43:44Z

Allow perf probe to work on ppc ABIv1 without the need to specify the leading dot '.' for functions. 'perf probe do_fork' works with this patch. We do this by changing how symbol name comparison works on ppc ABIv1 - we simply ignore and skip over the initial dot, if one exists, during symbol name comparison. Signed-off-by: Naveen N. Rao Reviewed-by: Srikar Dronamraju Cc: Ananth N Mavinakayanahalli Cc: Masami Hiramatsu Cc: Michael Ellerman Cc: Sukadev Bhattiprolu Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/652a8f3bfa919bd02a1836a128370eaed59b4a34.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf probe ppc: Use the right prefix when ignoring SyS symbols on ppc

2015-05-04T15:43:43Z

Use the proper prefix when ignoring SyS symbols on ppc ABIv1. While at it, generalize symbol selection so architectures can implement their own logic. Signed-off-by: Naveen N. Rao Reviewed-by: Srikar Dronamraju Cc: Ananth N Mavinakayanahalli Cc: Masami Hiramatsu Cc: Michael Ellerman Cc: Sukadev Bhattiprolu Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/adf1f98b121ecaf292777fe5cc69fe1038feabce.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf probe ppc: Fix symbol fixup issues due to ELF type

2015-05-04T15:43:42Z

If using the symbol table, symbol addresses are not being fixed up properly, resulting in probes being placed at wrong addresses: # perf probe do_fork Added new event: probe:do_fork (on do_fork) You can now use it in all perf tools, such as: perf record -e probe:do_fork -aR sleep 1 # cat /sys/kernel/debug/tracing/kprobe_events p:probe/do_fork _text+635952 # printf "%x" 635952 9b430 # grep do_fork /boot/System.map c0000000000ab430 T .do_fork Fix by checking for ELF type ET_DYN used by ppc64 kernels. Signed-off-by: Naveen N. Rao Reviewed-by: Srikar Dronamraju Cc: Ananth N Mavinakayanahalli Cc: Masami Hiramatsu Cc: Michael Ellerman Cc: Sukadev Bhattiprolu Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/41392bb856ef62d929995e0b61967689b7915207.1430217967.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo