kernel/tools/perf/util/symbol-minimal.c, branch linux-4.3.y

perf symbols: Save DSO loading errno to better report errors

2015-03-24T15:08:43Z

Before, when some problem happened while trying to load the kernel symtab, 'perf top' would show: ┌─Warning:───────────────────────────┐ │The vmlinux file can't be used. │ │Kernel samples will not be resolved.│ │ │ │ │ │Press any key... │ └────────────────────────────────────┘ Now, it reports: # perf top --vmlinux /dev/null ┌─Warning:───────────────────────────────────────────┐ │The /tmp/passwd file can't be used: Invalid ELF file│ │Kernel samples will not be resolved. │ │ │ │ │ │Press any key... │ └────────────────────────────────────────────────────┘ This is possible because we now register the reason for not being able to load the symtab in the dso->load_errno member, and provide a dso__strerror_load() routine to format this error into a strerror like string with a short reason for the error while loading. That can be just forwarding the dso__strerror_load() call to strerror_r(), or, for a separate errno range providing a custom message. Reported-by: Ingo Molnar Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Namhyung Kim Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-u5rb5uq63xqhkfb8uv2lxd5u@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Fix use after free in filename__read_build_id

2014-12-17T14:58:17Z

In filename__read_build_id, phdr points to memory in buf, which gets realloced before a call to fseek that uses phdr->p_offset. This change stores the value of p_offset before buf is realloced, so the fseek can use the value safely. Signed-off-by: Mitchell Krome Cc: Jiri Olsa Cc: Ingo Molnar Cc: Jiri Olsa Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20141216021612.GA7199@mitchell Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Fallback to kallsyms when using the minimal 'ELF' loader

2014-11-19T15:33:46Z

The minimal ELF loader should not return 1 when it manages to read the vmlinux build-id, it should instead return 0, meaning that it hasn't loaded any symbols, since it doesn't parses ELF at all. That way, the main symbol.c routines will understand that it is necessary to continue looking for a file with symbols, and when no libelf is linked, that means it will eventually try kallsyms. Reported-by: Peter Zijlstra Tested-by: Peter Zijlstra Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/20141111130326.GT18464@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add dso__type()

2014-07-23T20:36:36Z

dso__type() determines wheather a dso is 32-bit, x32 (32-bit with 64-bit registers) or 64-bit. dso__type() will be used to determine the VDSO a program maps. Reviewed-by: Jiri Olsa Signed-off-by: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1406035081-14301-51-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Record whether a dso is 64-bit

2014-07-16T20:57:35Z

Add a flag to 'struct dso' to record if the dso is 64-bit or not. Update the flag when reading the ELF. This is needed for instruction decoding. For example, x86 instruction decoding depends on whether or not the 64-bit instruction set is used. Signed-off-by: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1405332185-4050-18-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

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

2013-12-27T20:08:19Z

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

2013-12-04T18:08:19Z

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

2013-10-14T15:20:38Z

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

2013-10-14T13:29:00Z

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

2013-08-07T20:35:33Z

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