linux-toradex.git/tools/perf/util/symbol-minimal.c, branch v3.14-rc2

perf tools: Use zfree to help detect use after free bugs

2013-12-27T20:08:19+00:00

Several areas already used this technique, so do some audit to
consistently use it elsewhere.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Mike Galbraith 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-9sbere0kkplwe45ak6rk4a1f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Fix random fd closing with no libelf

2013-12-04T18:08:19+00:00

When built without libelf, perf tools was failing to initialize a file
descriptor, but nevertheless closing it.  That sometimes resulted in the
output being truncated because the stdout file descriptor got closed.

Signed-off-by: Adrian Hunter 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Mike Galbraith 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1386166981-30197-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-cache: Add ability to add kcore to the cache

2013-10-14T15:20:38+00:00

kcore can be used to view the running kernel object code.  However,
kcore changes as modules are loaded and unloaded, and when the kernel
decides to modify its own code.  Consequently it is useful to create a
copy of kcore at a particular time.  Unlike vmlinux, kcore is not unique
for a given build-id.  And in addition, the kallsyms and modules files
are also needed.  The tool therefore creates a directory:

	~/.debug/[kernel.kcore]//

which contains: kcore, kallsyms and modules.

Note that the copied kcore contains only code sections.  See the
kcore_copy() function for how that is determined.

The tool will not make additional copies of kcore if there is already
one with the same modules at the same addresses.

Currently, perf tools will not look for kcore in the cache.  That is
addressed in another patch.

Signed-off-by: Adrian Hunter 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Mike Galbraith 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/525BF849.5030405@intel.com
[ renamed 'index' to 'idx' to avoid shadowing string.h symbol in f12,
  use at least one member initializer when initializing a struct to
  zeros, also to fix the build on f12 ]
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Workaround objdump difficulties with kcore

2013-10-14T13:29:00+00:00

The objdump tool fails to annotate module symbols when looking at kcore.

Workaround this by extracting object code from kcore and putting it in a
temporary file for objdump to use instead.

The temporary file is created to look like kcore but contains only the
function being disassembled.

Signed-off-by: Adrian Hunter 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Mike Galbraith 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1381320078-16497-3-git-send-email-adrian.hunter@intel.com
[ Renamed 'index' to 'idx' to avoid shadowing string.h's 'index' in Fedora 12,
  Replace local with variable length with malloc/free to fix build in Fedora 12 ]
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Add support for reading from /proc/kcore

2013-08-07T20:35:33+00:00

In the absence of vmlinux, perf tools uses kallsyms for symbols.  If the
user has access, now also map to /proc/kcore.

The dso data_type is now set to either DSO_BINARY_TYPE__KCORE or
DSO_BINARY_TYPE__GUEST_KCORE as approprite.

This patch breaks the "vmlinux symtab matches kallsyms" test.  That is
fixed in a following patch.

Signed-off-by: Adrian Hunter 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Mike Galbraith 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1375875537-4509-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Include elf.h header regardless LIBELF_SUPPORT

2013-01-24T19:40:18+00:00

The elf.h header file is used for NO_LIBELF build too so it should be
included anyway.  Also remove duplicated include of the header file in
symbol-*.c.  This patch fixes following build error on NO_LIBELF build:

    CC tests/hists_link.o
tests/hists_link.c: In function ‘setup_fake_machine’:
tests/hists_link.c:132:8: error: ‘STB_GLOBAL’ undeclared (first use in this function)
tests/hists_link.c:132:8: note: each undeclared identifier is reported only once for each function it appears in

Signed-off-by: Namhyung Kim 
Cc: David Ahern 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1356679009-32122-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use __maybe_used for unused variables

2012-09-11T15:19:15+00:00

perf defines both __used and __unused variables to use for marking
unused variables. The variable __used is defined to
__attribute__((__unused__)), which contradicts the kernel definition to
__attribute__((__used__)) for new gcc versions. On Android, __used is
also defined in system headers and this leads to warnings like: warning:
'__used__' attribute ignored

__unused is not defined in the kernel and is not a standard definition.
If __unused is included everywhere instead of __used, this leads to
conflicts with glibc headers, since glibc has a variables with this name
in its headers.

The best approach is to use __maybe_unused, the definition used in the
kernel for __attribute__((unused)). In this way there is only one
definition in perf sources (instead of 2 definitions that point to the
same thing: __used and __unused) and it works on both Linux and Android.
This patch simply replaces all instances of __used and __unused with
__maybe_unused.

Signed-off-by: Irina Tirdea 
Acked-by: Pekka Enberg 
Cc: David Ahern 
Cc: Ingo Molnar 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/1347315303-29906-7-git-send-email-irina.tirdea@intel.com
[ committer note: fixed up conflict with a116e05 in builtin-sched.c ]
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Use both runtime and debug images

2012-08-13T17:46:55+00:00

We keep both a 'runtime' elf image as well as a 'debug' elf image around
and generate symbols by looking at both of these.

This eliminates the need for the want_symtab/goto restart mechanism
combined with iterating over and reopening the elf images a second time.

Also give dso__synthsize_plt_symbols() the runtime image (which has
dynsyms) instead of the symbol image (which may only have a symtab and
no dynsyms).

Previously if a debug image was found all runtime images were ignored.

This fixes 2 issues:

 - Symbol resolution to failure on PowerPC systems with debug symbols
   installed, as the debug images lack a '.opd' section which contains
   function descriptors.

 - On all archs, plt synthesis failed when a debug image was loaded and
   that debug image lacks a dynsym section while a runtime image has a
   dynsym section.

Assumptions:

 - If a .opd section exists, it is contained in the highest priority
   image with a dynsym section.

 - This generally implies that the debug image lacks a dynsym section
   (ie: it is marked as NO_BITS).

Signed-off-by: Cody P Schafer 
Cc: David Hansen 
Cc: Ingo Molnar 
Cc: Matt Hellsley 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Sukadev Bhattiprolu 
Link: http://lkml.kernel.org/r/1344637382-22789-17-git-send-email-cody@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Convert dso__load_syms to take 2 symsrc's

2012-08-13T17:41:33+00:00

To properly handle platforms with an opd section, both a runtime image
(which contains the opd section but possibly lacks symbols) and a symbol
image (which probably lacks an opd section but has symbols).

The next patch ("perf symbol: use both runtime and debug images")
adjusts the callsite in dso__load() to take advantage of being able to
pass both runtime & debug images.

Assumptions made here:

 - The opd section, if it exists in the runtime image, has headers in
   both the runtime image and the debug/syms image.

 - The index of the opd section (again, only if it exists in the runtime
   image) is the same in both the runtime and debug/symbols image.

Both of these are true on RHEL, but it is unclear how accurate they are
in general (on platforms with function descriptors in opd sections).

Signed-off-by: Cody P Schafer 
Cc: David Hansen 
Cc: Ingo Molnar 
Cc: Matt Hellsley 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Sukadev Bhattiprolu 
Link: http://lkml.kernel.org/r/1344637382-22789-16-git-send-email-cody@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Factor want_symtab out of dso__load_sym()

2012-08-13T17:37:37+00:00

Only one callsite of dso__load_sym() uses the want_symtab functionality,
so place the logic at the callsite instead of within dso__load_sym().

This sets us up for removal of want_symtab completely once we keep
multiple elf handles (within symsrc's) around.

Setup for the later patch

"perf symbols: Use both runtime and debug images"

Signed-off-by: Cody P Schafer 
Cc: David Hansen 
Cc: Ingo Molnar 
Cc: Matt Hellsley 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Sukadev Bhattiprolu 
Link: http://lkml.kernel.org/r/1344637382-22789-15-git-send-email-cody@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo