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* objtool: Add several performance improvementsJosh Poimboeuf2016-03-093-14/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use hash tables for instruction and rela lookups (and keep the linked lists around for sequential access). Also cache the section struct for the "__func_stack_frame_non_standard" section. With this change, "objtool check net/wireless/nl80211.o" goes from: real 0m1.168s user 0m1.163s sys 0m0.005s to: real 0m0.059s user 0m0.042s sys 0m0.017s for a 20x speedup. With the same object, it should be noted that the memory heap usage grew from 8MB to 62MB. Reducing the memory usage is on the TODO list. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/dd0d8e1449506cfa7701b4e7ba73577077c44253.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* tools: Copy hashtable.h into tools directoryJosh Poimboeuf2016-03-094-3/+155
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Copy hashtable.h from include/linux/tools.h. It's needed by objtool in the next patch in the series. Add some includes that it needs, and remove references to kernel-specific features like RCU and __read_mostly. Also change some if its dependency headers' includes to use quotes instead of brackets so gcc can find them. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/be3bef72f6540d8a510515408119d968a0e18179.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix false positive warnings for functions with multiple switch ↵Josh Poimboeuf2016-03-091-45/+100
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | statements Ingo reported [1] some false positive objtool warnings: drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x2e7: frame pointer state mismatch drivers/net/wireless/realtek/rtlwifi/base.o: warning: objtool: rtlwifi_rate_mapping()+0x2f3: frame pointer state mismatch ... And so did the 0-day bot [2]: drivers/gpu/drm/radeon/cik.o: warning: objtool: cik_tiling_mode_table_init()+0x6ce: call without frame pointer save/setup drivers/gpu/drm/radeon/cik.o: warning: objtool: cik_tiling_mode_table_init()+0x72b: call without frame pointer save/setup ... Both sets of warnings involve functions which have multiple switch statements. When there's more than one switch statement in a function, objtool interprets all the switch jump tables as a single table. If the targets of one jump table assume a stack frame and the targets of another one don't, it prints false positive warnings. Fix the bug by detecting the size of each switch jump table. For multiple tables, each one ends where the next one begins. [1] https://lkml.kernel.org/r/20160308103716.GA9618@gmail.com [2] https://lists.01.org/pipermail/kbuild-all/2016-March/018124.html Reported-by: Ingo Molnar <mingo@kernel.org> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/2d7eecc6bc52d301f494b80f5fd62c2b6c895658.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Rename some variables and functionsJosh Poimboeuf2016-03-093-52/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename some list heads to distinguish them from hash node heads, which are added later in the patch series. Also rename the get_*() functions to add_*(), which is more descriptive: they "add" data to the objtool_file struct. Also rename rodata_rela and text_rela to be clearer: - text_rela refers to a rela entry in .rela.text. - rodata_rela refers to a rela entry in .rela.rodata. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/ee0eca2bba8482aa45758958c5586c00a7b71e62.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Remove superflous INIT_LIST_HEADJosh Poimboeuf2016-03-091-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | The insns list is initialized twice, in cmd_check() and in decode_instructions(). Remove the latter. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/be6e21d7eec1f072095d22a1cbe144057135e097.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Add helper macros for traversing instructionsJosh Poimboeuf2016-03-091-73/+55
| | | | | | | | | | | | | | | | | | | | | | | | | Add some helper macros to make it easier to traverse instructions, and to abstract the details of the instruction list implementation in preparation for creating a hash structure. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/8e1715d5035bc02b4db28d0fccef6bb1170d1f12.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix false positive warnings related to sibling callsJosh Poimboeuf2016-03-091-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With some configs [1], objtool prints a bunch of false positive warnings like: arch/x86/events/core.o: warning: objtool: x86_del_exclusive()+0x0: frame pointer state mismatch For some reason this config has a bunch of sibling calls. When objtool follows a sibling call jump, it attempts to compare the frame pointer state. But it also accidentally compares the FENTRY state, resulting in a false positive warning. [1] https://lkml.kernel.org/r/20160308154909.GA20956@gmail.com Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/382de77ccaaa8cd79b27a155c3d109ebd4ce0219.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Compile with debugging symbolsJosh Poimboeuf2016-03-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Compile objtool with debugging symbols ('-g') to help tools like perf and gdb understand what it's doing. Combined with '-O2', it's not always helpful, but it's better than nothing. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/c295e9ee9ed360dc8b2e1d180c859f11cfc151ef.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Detect infinite recursionJosh Poimboeuf2016-03-091-12/+33
| | | | | | | | | | | | | | | | | | | | | | | | I don't _think_ dead_end_function() can get into a recursive loop, but just in case, stop the loop and print a warning. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/ff489a63e6feb88abb192cfb361d81626dcf3e89.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Prevent infinite recursion in noreturn detectionJosh Poimboeuf2016-03-091-4/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ingo reported an infinite loop in objtool with a certain randconfig [1]. With the given config, two functions in crypto/ablkcipher.o contained sibling calls to each other, which threw the recursive call in dead_end_function() for a loop (literally!). Split the noreturn detection into two passes. In the first pass, check for return instructions. In the second pass, do the potentially recursive sibling call check. In most cases, the first pass will be good enough. In the rare case where a second pass is needed, recursion should hopefully no longer be possible. [1] https://lkml.kernel.org/r/20160308154909.GA20956@gmail.com Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/16afb602640ef43b7782087d6cca17bf6fc13603.1457502970.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Support CROSS_COMPILEJosh Poimboeuf2016-03-032-9/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_STACK_VALIDATION on a ppc64le host with an x86 cross-compiler, Stephen Rothwell saw the following objtool build errors: DESCEND objtool CC /home/sfr/next/x86_64_allmodconfig/tools/objtool/builtin-check.o CC /home/sfr/next/x86_64_allmodconfig/tools/objtool/special.o CC /home/sfr/next/x86_64_allmodconfig/tools/objtool/elf.o CC /home/sfr/next/x86_64_allmodconfig/tools/objtool/objtool.o MKDIR /home/sfr/next/x86_64_allmodconfig/tools/objtool/arch/x86/insn/ CC /home/sfr/next/x86_64_allmodconfig/tools/objtool/libstring.o elf.c:22:23: fatal error: sys/types.h: No such file or directory compilation terminated. CC /home/sfr/next/x86_64_allmodconfig/tools/objtool/exec-cmd.o CC /home/sfr/next/x86_64_allmodconfig/tools/objtool/help.o builtin-check.c:28:20: fatal error: string.h: No such file or directory compilation terminated. objtool.c:28:19: fatal error: stdio.h: No such file or directory compilation terminated. It fails to build because it tries to compile objtool with the cross-compiler instead of the host compiler. Ensure that it always uses the host compiler by ignoring CROSS_COMPILE. In order to do that properly, the libsubcmd.a library needs to be built in tools/objtool/ rather than tools/lib/subcmd/. The latter directory contains the cross-compiled version which is needed for perf and possibly other tools. Note that cross-compiling for x86 on a _big_ endian system would result in a bunch of false positive objtool warnings during the kernel build because it isn't endian-aware. But that's generally a rare edge case and there haven't been any reports of anybody needing that. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/55b63eefc347f1bb28573f972d8d1adbf1f1c31d.1456962210.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/decoder: Use explicitly signed charsJosh Poimboeuf2016-03-032-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running objtool on a ppc64le host to analyze x86 binaries, it reports a lot of false warnings like: ipc/compat_mq.o: warning: objtool: compat_SyS_mq_open()+0x91: can't find jump dest instruction at .text+0x3a5 The warnings are caused by the x86 instruction decoder setting the wrong value for the jump instruction's immediate field because it assumes that "char == signed char", which isn't true for all architectures. When converting char to int, gcc sign-extends on x86 but doesn't sign-extend on ppc64le. According to the gcc man page, that's a feature, not a bug: > Each kind of machine has a default for what "char" should be. It is > either like "unsigned char" by default or like "signed char" by > default. > > Ideally, a portable program should always use "signed char" or > "unsigned char" when it depends on the signedness of an object. Conform to the "standards" by changing the "char" casts to "signed char". This results in no actual changes to the object code on x86. Note: the x86 decoder now lives in three different locations in the kernel tree, which are all kept in sync via makefile checks and warnings: in-kernel, perf, and objtool. This fixes all three locations. Eventually we should probably try to at least converge the two separate "tools" locations into a single shared location. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/9dd4161719b20e6def9564646d68bfbe498c549f.1456962210.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Add tool to perform compile-time stack metadata validationJosh Poimboeuf2016-02-2923-6/+5173
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a host tool named objtool which has a "check" subcommand which analyzes .o files to ensure the validity of stack metadata. It enforces a set of rules on asm code and C inline assembly code so that stack traces can be reliable. For each function, it recursively follows all possible code paths and validates the correct frame pointer state at each instruction. It also follows code paths involving kernel special sections, like .altinstructions, __jump_table, and __ex_table, which can add alternative execution paths to a given instruction (or set of instructions). Similarly, it knows how to follow switch statements, for which gcc sometimes uses jump tables. Here are some of the benefits of validating stack metadata: a) More reliable stack traces for frame pointer enabled kernels Frame pointers are used for debugging purposes. They allow runtime code and debug tools to be able to walk the stack to determine the chain of function call sites that led to the currently executing code. For some architectures, frame pointers are enabled by CONFIG_FRAME_POINTER. For some other architectures they may be required by the ABI (sometimes referred to as "backchain pointers"). For C code, gcc automatically generates instructions for setting up frame pointers when the -fno-omit-frame-pointer option is used. But for asm code, the frame setup instructions have to be written by hand, which most people don't do. So the end result is that CONFIG_FRAME_POINTER is honored for C code but not for most asm code. For stack traces based on frame pointers to be reliable, all functions which call other functions must first create a stack frame and update the frame pointer. If a first function doesn't properly create a stack frame before calling a second function, the *caller* of the first function will be skipped on the stack trace. For example, consider the following example backtrace with frame pointers enabled: [<ffffffff81812584>] dump_stack+0x4b/0x63 [<ffffffff812d6dc2>] cmdline_proc_show+0x12/0x30 [<ffffffff8127f568>] seq_read+0x108/0x3e0 [<ffffffff812cce62>] proc_reg_read+0x42/0x70 [<ffffffff81256197>] __vfs_read+0x37/0x100 [<ffffffff81256b16>] vfs_read+0x86/0x130 [<ffffffff81257898>] SyS_read+0x58/0xd0 [<ffffffff8181c1f2>] entry_SYSCALL_64_fastpath+0x12/0x76 It correctly shows that the caller of cmdline_proc_show() is seq_read(). If we remove the frame pointer logic from cmdline_proc_show() by replacing the frame pointer related instructions with nops, here's what it looks like instead: [<ffffffff81812584>] dump_stack+0x4b/0x63 [<ffffffff812d6dc2>] cmdline_proc_show+0x12/0x30 [<ffffffff812cce62>] proc_reg_read+0x42/0x70 [<ffffffff81256197>] __vfs_read+0x37/0x100 [<ffffffff81256b16>] vfs_read+0x86/0x130 [<ffffffff81257898>] SyS_read+0x58/0xd0 [<ffffffff8181c1f2>] entry_SYSCALL_64_fastpath+0x12/0x76 Notice that cmdline_proc_show()'s caller, seq_read(), has been skipped. Instead the stack trace seems to show that cmdline_proc_show() was called by proc_reg_read(). The benefit of "objtool check" here is that because it ensures that *all* functions honor CONFIG_FRAME_POINTER, no functions will ever[*] be skipped on a stack trace. [*] unless an interrupt or exception has occurred at the very beginning of a function before the stack frame has been created, or at the very end of the function after the stack frame has been destroyed. This is an inherent limitation of frame pointers. b) 100% reliable stack traces for DWARF enabled kernels This is not yet implemented. For more details about what is planned, see tools/objtool/Documentation/stack-validation.txt. c) Higher live patching compatibility rate This is not yet implemented. For more details about what is planned, see tools/objtool/Documentation/stack-validation.txt. To achieve the validation, "objtool check" enforces the following rules: 1. Each callable function must be annotated as such with the ELF function type. In asm code, this is typically done using the ENTRY/ENDPROC macros. If objtool finds a return instruction outside of a function, it flags an error since that usually indicates callable code which should be annotated accordingly. This rule is needed so that objtool can properly identify each callable function in order to analyze its stack metadata. 2. Conversely, each section of code which is *not* callable should *not* be annotated as an ELF function. The ENDPROC macro shouldn't be used in this case. This rule is needed so that objtool can ignore non-callable code. Such code doesn't have to follow any of the other rules. 3. Each callable function which calls another function must have the correct frame pointer logic, if required by CONFIG_FRAME_POINTER or the architecture's back chain rules. This can by done in asm code with the FRAME_BEGIN/FRAME_END macros. This rule ensures that frame pointer based stack traces will work as designed. If function A doesn't create a stack frame before calling function B, the _caller_ of function A will be skipped on the stack trace. 4. Dynamic jumps and jumps to undefined symbols are only allowed if: a) the jump is part of a switch statement; or b) the jump matches sibling call semantics and the frame pointer has the same value it had on function entry. This rule is needed so that objtool can reliably analyze all of a function's code paths. If a function jumps to code in another file, and it's not a sibling call, objtool has no way to follow the jump because it only analyzes a single file at a time. 5. A callable function may not execute kernel entry/exit instructions. The only code which needs such instructions is kernel entry code, which shouldn't be be in callable functions anyway. This rule is just a sanity check to ensure that callable functions return normally. It currently only supports x86_64. I tried to make the code generic so that support for other architectures can hopefully be plugged in relatively easily. On my Lenovo laptop with a i7-4810MQ 4-core/8-thread CPU, building the kernel with objtool checking every .o file adds about three seconds of total build time. It hasn't been optimized for performance yet, so there are probably some opportunities for better build performance. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/f3efb173de43bd067b060de73f856567c0fa1174.1456719558.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'x86/debug' into core/objtool, to pick up frame pointer fixesIngo Molnar2016-02-254-36/+452
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Merge branch 'x86/urgent' into x86/asm, to pick up fixesIngo Molnar2016-02-1828-63/+1510
| |\ | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | selftests/x86: Add a test for syscall restart under ptraceAndy Lutomirski2016-02-171-0/+126
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This catches a regression from the compat syscall rework. The 32-bit variant of this test currently fails. The issue is that, for a 32-bit tracer and a 32-bit tracee, GETREGS+SETREGS with no changes should be a no-op. It currently isn't a no-op if RAX indicates signal restart, because the high bits get cleared and the kernel loses track of the restart state. Reported-by: Robert O'Callahan <robert@ocallahan.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/c4040b40b5b4a37ed31375a69b683f753ec6788a.1455142412.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | selftests/x86: Fix some error messages in ptrace_syscallAndy Lutomirski2016-02-171-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I had some obvious typos. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert O'Callahan <robert@ocallahan.org> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/e5e6772d4802986cf7df702e646fa24ac14f2204.1455142412.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | selftests/x86: Add tests for UC_SIGCONTEXT_SS and UC_STRICT_RESTORE_SSAndy Lutomirski2016-02-171-28/+202
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This tests the two ABI-preserving cases that DOSEMU cares about, and it also explicitly tests the new UC_SIGCONTEXT_SS and UC_STRICT_RESTORE_SS flags. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Brian Gerst <brgerst@gmail.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Stas Sergeev <stsp@list.ru> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/f3d08f98541d0bd3030ceb35e05e21f59e30232c.1455664054.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/signal/64: Re-add support for SS in the 64-bit signal contextAndy Lutomirski2016-02-171-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a second attempt to make the improvements from c6f2062935c8 ("x86/signal/64: Fix SS handling for signals delivered to 64-bit programs"), which was reverted by 51adbfbba5c6 ("x86/signal/64: Add support for SS in the 64-bit signal context"). This adds two new uc_flags flags. UC_SIGCONTEXT_SS will be set for all 64-bit signals (including x32). It indicates that the saved SS field is valid and that the kernel supports the new behavior. The goal is to fix a problems with signal handling in 64-bit tasks: SS wasn't saved in the 64-bit signal context, making it awkward to determine what SS was at the time of signal delivery and making it impossible to return to a non-flat SS (as calling sigreturn clobbers SS). This also made it extremely difficult for 64-bit tasks to return to fully-defined 16-bit contexts, because only the kernel can easily do espfix64, but sigreturn was unable to set a non-flag SS:ESP. (DOSEMU has a monstrous hack to partially work around this limitation.) If we could go back in time, the correct fix would be to make 64-bit signals work just like 32-bit signals with respect to SS: save it in signal context, reset it when delivering a signal, and restore it in sigreturn. Unfortunately, doing that (as I tried originally) breaks DOSEMU: DOSEMU wouldn't reset the signal context's SS when clearing the LDT and changing the saved CS to 64-bit mode, since it predates the SS context field existing in the first place. This patch is a bit more complicated, and it tries to balance a bunch of goals. It makes most cases of changing ucontext->ss during signal handling work as expected. I do this by special-casing the interesting case. On sigreturn, ucontext->ss will be honored by default, unless the ucontext was created from scratch by an old program and had a 64-bit CS (unfortunately, CRIU can do this) or was the result of changing a 32-bit signal context to 64-bit without resetting SS (as DOSEMU does). For the benefit of new 64-bit software that uses segmentation (new versions of DOSEMU might), the new behavior can be detected with a new ucontext flag UC_SIGCONTEXT_SS. To avoid compilation issues, __pad0 is left as an alias for ss in ucontext. The nitty-gritty details are documented in the header file. This patch also re-enables the sigreturn_64 and ldt_gdt_64 selftests, as the kernel change allows both of them to pass. Tested-by: Stas Sergeev <stsp@list.ru> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Brian Gerst <brgerst@gmail.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/749149cbfc3e75cd7fcdad69a854b399d792cc6f.1455664054.git.luto@kernel.org [ Small readability edit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | selftests/x86: Add check_initial_reg_state()Andy Lutomirski2016-01-292-1/+117
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This checks that ELF binaries are started with an appropriately blank register state. ( There's currently a nasty special case in the entry asm to arrange for this. I'm planning on removing the special case, and this will help make sure I don't break it. ) Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/ef54f8d066b30a3eb36bbf26300eebb242185700.1454022279.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | selftests/x86: Extend Makefile to allow 64-bit-only testsAndy Lutomirski2016-01-291-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously the Makefile supported 32-bit-only tests and tests that were 32-bit and 64-bit. This adds the support for tests that are only built as 64-bit binaries. There aren't any yet, but there might be a few some day. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shuah Khan <shuahkhan@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-api@vger.kernel.org Link: http://lkml.kernel.org/r/99789bfe65706e6df32cc7e13f656e8c9fa92031.1454022279.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge tag 'trace-fixes-v4.5-rc5' of ↵Linus Torvalds2016-02-221-10/+5
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Two more small fixes. One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the stack made by the stack tracer. As the stack tracer scans the entire kernel stack, KASAN triggers seeing it as a "stack out of bounds" error. As the scan is looking at the contents of the stack from parent functions. The NOCHECK() tells KASAN that this is done on purpose, and is not some kind of stack overflow. The second fix is to the ftrace selftests, to retrieve the PID of executed commands from the shell with '$!' and not by parsing 'jobs'" * tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing, kasan: Silence Kasan warning in check_stack of stack_tracer ftracetest: Fix instance test to use proper shell command for pids
| * | ftracetest: Fix instance test to use proper shell command for pidsSteven Rostedt2016-02-191-10/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ftracetest instance test used parsing of the "jobs" output to find the pid of the subshell that is executed previously. But this is not portable to all major shells that may run these tests. The proper way to get the pid of the subshell is the shell command "$!". This will return the pid of the previously executed command. Use that instead, otherwise the test does not work in all environments. Link: http://lkml.kernel.org/r/20151211143617.65f4d7a1@gandalf.local.home Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | Merge tag 'efi-urgent' of ↵Ingo Molnar2016-02-162-4/+87
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent Pull EFI fixes from Matt Fleming: * Prevent accidental deletion of EFI variables through efivarfs that may brick machines. We use a whitelist of known-safe variables to allow things like installing distributions to work out of the box, and instead restrict vendor-specific variable deletion by making non-whitelist variables immutable (Peter Jones) Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | efi: Make efivarfs entries immutable by defaultPeter Jones2016-02-102-4/+87
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "rm -rf" is bricking some peoples' laptops because of variables being used to store non-reinitializable firmware driver data that's required to POST the hardware. These are 100% bugs, and they need to be fixed, but in the mean time it shouldn't be easy to *accidentally* brick machines. We have to have delete working, and picking which variables do and don't work for deletion is quite intractable, so instead make everything immutable by default (except for a whitelist), and make tools that aren't quite so broad-spectrum unset the immutable flag. Signed-off-by: Peter Jones <pjones@redhat.com> Tested-by: Lee, Chun-Yi <jlee@suse.com> Acked-by: Matthew Garrett <mjg59@coreos.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
* | | Merge tag 'perf-urgent-for-mingo-2' of ↵Ingo Molnar2016-02-041-0/+10
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fix from Arnaldo Carvalho de Melo: - Fix 'perf stat' interval output values (Jiri Olsa) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | perf stat: Fix interval output valuesJiri Olsa2016-02-031-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We broke interval data displays with commit: 3f416f22d1e2 ("perf stat: Do not clean event's private stats") This commit removed stats cleaning, which is important for '-r' option to carry counters data over the whole run. But it's necessary to clean it for interval mode, otherwise the displayed value is avg of all previous values. Before: $ perf stat -e cycles -a -I 1000 record # time counts unit events 1.000240796 75,216,287 cycles 2.000512791 107,823,524 cycles $ perf stat report # time counts unit events 1.000240796 75,216,287 cycles 2.000512791 91,519,906 cycles Now: $ perf stat report # time counts unit events 1.000240796 75,216,287 cycles 2.000512791 107,823,524 cycles Notice the second value being bigger (91,.. < 107,..). This could be easily verified by using perf script which displays raw stat data: $ perf script CPU THREAD VAL ENA RUN TIME EVENT 0 -1 23855779 1000209530 1000209530 1000240796 cycles 1 -1 33340397 1000224964 1000224964 1000240796 cycles 2 -1 15835415 1000226695 1000226695 1000240796 cycles 3 -1 2184696 1000228245 1000228245 1000240796 cycles 0 -1 97014312 2000514533 2000514533 2000512791 cycles 1 -1 46121497 2000543795 2000543795 2000512791 cycles 2 -1 32269530 2000543566 2000543566 2000512791 cycles 3 -1 7634472 2000544108 2000544108 2000512791 cycles The sum of the first 4 values is the first interval aggregated value: 23855779 + 33340397 + 15835415 + 2184696 = 75,216,287 The sum of the second 4 values minus first value is the second interval aggregated value: 97014312 + 46121497 + 32269530 + 7634472 - 75216287 = 107,823,524 Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1454485436-20639-1-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | | | Merge tag 'perf-urgent-for-mingo' of ↵Ingo Molnar2016-02-044-26/+53
|\| | | | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes from Arnaldo Carvalho de Melo: - tracepoint_error() can receive e=NULL, robustify it, fixes a problem noticed with a very specific combination: Machine with Intel PT (e.g. Broadwell), kernel with no perf_event_attr.context_switch feature (e.g. 4.2) and unreadable tracefs (for instance !root users), making the fallback from perf_event_attr.context_switch to the sched:sched_switch tracepoint to fail reading its info from tracefs, fix it. (Adrian Hunter) - Fix segfault in intel PT, by making it follow the 'struct thread' lifetime cycle checking expectations, noticed for instance, when processing perf.data files with Intel PT data using 'perf script' and when exiting 'perf report' (Adrian Hunter) - Fix CFI usage from .eh_frame and .debug_frame, which sometimes requires that we fallback from .eh_frame to .debug_frame in architectures such as PowerPC (Hemant Kumar) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | perf probe: Search both .eh_frame and .debug_frame sections for probe locationHemant Kumar2016-02-022-26/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'perf probe' through debuginfo__find_probes() in util/probe-finder.c checks for the functions' frame descriptions in either .eh_frame section of an ELF or the .debug_frame. The check is based on whether either one of these sections is present. Depending on distro, toolchain defaults, architetcutre, build flags, etc., CFI might be found in either .eh_frame and/or .debug_frame. Sometimes, it may happen that, .eh_frame, even if present, may not be complete and may miss some descriptions. Therefore, to be sure, to find the CFI covering an address we will always have to investigate both if available. For e.g., in powerpc, this may happen: $ gcc -g bin.c -o bin $ objdump --dwarf ./bin <1><145>: Abbrev Number: 7 (DW_TAG_subprogram) <146> DW_AT_external : 1 <146> DW_AT_name : (indirect string, offset: 0x9e): main <14a> DW_AT_decl_file : 1 <14b> DW_AT_decl_line : 39 <14c> DW_AT_prototyped : 1 <14c> DW_AT_type : <0x57> <150> DW_AT_low_pc : 0x100007b8 If the .eh_frame and .debug_frame are checked for the same binary, we will find that, .eh_frame (although present) doesn't contain a description for "main" function. But, .debug_frame has a description: 000000d8 00000024 00000000 FDE cie=00000000 pc=100007b8..10000838 DW_CFA_advance_loc: 16 to 100007c8 DW_CFA_def_cfa_offset: 144 DW_CFA_offset_extended_sf: r65 at cfa+16 ... Due to this (since, perf checks whether .eh_frame is present and goes on searching for that address inside that frame), perf is unable to process the probes: # perf probe -x ./bin main Failed to get call frame on 0x100007b8 Error: Failed to add events. To avoid this issue, we need to check both the sections (.eh_frame and .debug_frame), which is done in this patch. Note that, we can always force everything into both .eh_frame and .debug_frame by: $ gcc bin.c -fasynchronous-unwind-tables -fno-dwarf2-cfi-asm -g -o bin Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: Mark Wielaard <mjw@redhat.com> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1454426806-13974-1-git-send-email-hemant@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | perf tools: Fix thread lifetime related segfaut in intel_ptAdrian Hunter2016-02-021-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | intel_pt_process_auxtrace_info() creates a pt->unknown_thread thread that eventually needs to be freed by the last thread__put() on it, when its refcount hits zero, which may happen in intel_pt_process_auxtrace_info() error handling path and triggers the following segfault, which would happen as well at intel_pt_free, when tools using this intel_pt codebase frees up resources: # perf record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls 0 a anaconda-ks.cfg bin perf.data perf.data.old perf-f23-bringup.todo [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.217 MB perf.data ] # # perf script -F event,comm,pid,tid,time,addr,ip,sym,dso,iregs Samples for 'instructions:u' event do not have IREGS attribute set. Cannot print 'iregs' field. intel_pt_synth_events: failed to synthesize 'instructions' event type Segmentation fault (core dumped) # The problem is: there's a union in 'struct thread' combines a list_head and a rb_node. The standard life cycle of a thread is: init rb_node in the constructor, insert it into machine->threads rbtree using rb_node, move it to machine->dead_threads using list_head, clean in the last thread__put: list_del_init(&thread->node). In the above command, it clean a thread before adding it into list, causes the above segfault. Since pt->unknown_thread will never live in an rbtree, initialize its list node so that when list_del_init() is done on it we don't segfault. After this patch: # perf script -F event,comm,pid,tid,time,addr,ip,sym,dso,iregs Samples for 'instructions:u' event do not have IREGS attribute set. Cannot print 'iregs' field. intel_pt_synth_events: failed to synthesize 'instructions' event type 0x248 [0x88]: failed to process type: 70 # Reported-by: Tong Zhang <ztong@vt.edu> Reported-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Link: http://lkml.kernel.org/r/1454296865-19749-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | perf tools: tracepoint_error() can receive e=NULL, robustify itAdrian Hunter2016-02-011-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes segmentation fault using, for instance: (gdb) run record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls Starting program: /home/acme/bin/perf record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls Missing separate debuginfos, use: dnf debuginfo-install glibc-2.22-7.fc23.x86_64 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". Program received signal SIGSEGV, Segmentation fault. 0 x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410 (gdb) bt #0 0x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410 #1 0x00000000004b9fc5 in add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:433 #2 0x00000000004ba334 in add_tracepoint_event (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:498 #3 0x00000000004bb699 in parse_events_add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys=0x19b1370 "sched", event=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:936 #4 0x00000000004f6eda in parse_events_parse (_data=0x7fffffffb8b0, scanner=0x19a49d0) at util/parse-events.y:391 #5 0x00000000004bc8e5 in parse_events__scanner (str=0x663ff2 "sched:sched_switch", data=0x7fffffffb8b0, start_token=258) at util/parse-events.c:1361 #6 0x00000000004bca57 in parse_events (evlist=0x19a5220, str=0x663ff2 "sched:sched_switch", err=0x0) at util/parse-events.c:1401 #7 0x0000000000518d5f in perf_evlist__can_select_event (evlist=0x19a3b90, str=0x663ff2 "sched:sched_switch") at util/record.c:253 #8 0x0000000000553c42 in intel_pt_track_switches (evlist=0x19a3b90) at arch/x86/util/intel-pt.c:364 #9 0x00000000005549d1 in intel_pt_recording_options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at arch/x86/util/intel-pt.c:664 #10 0x000000000051e076 in auxtrace_record__options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at util/auxtrace.c:539 #11 0x0000000000433368 in cmd_record (argc=1, argv=0x7fffffffde60, prefix=0x0) at builtin-record.c:1264 #12 0x000000000049bec2 in run_builtin (p=0x8fa2a8 <commands+168>, argc=5, argv=0x7fffffffde60) at perf.c:390 #13 0x000000000049c12a in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:451 #14 0x000000000049c278 in run_argv (argcp=0x7fffffffdcbc, argv=0x7fffffffdcb0) at perf.c:495 #15 0x000000000049c60a in main (argc=5, argv=0x7fffffffde60) at perf.c:618 (gdb) Intel PT attempts to find the sched:sched_switch tracepoint but that seg faults if tracefs is not readable, because the error reporting structure is null, as errors are not reported when automatically adding tracepoints. Fix by checking before using. Committer note: This doesn't take place in a kernel that supports perf_event_attr.context_switch, that is the default way that will be used for tracking context switches, only in older kernels, like 4.2, in a machine with Intel PT (e.g. Broadwell) for non-priviledged users. Further info from a similar patch by Wang: The error is in tracepoint_error: it assumes the 'e' parameter is valid. However, there are many situation a parse_event() can be called without parse_events_error. See result of $ grep 'parse_events(.*NULL)' ./tools/perf/ -r' Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Tong Zhang <ztong@vt.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: stable@vger.kernel.org # v4.4+ Fixes: 196581717d85 ("perf tools: Enhance parsing events tracepoint error output") Link: http://lkml.kernel.org/r/1453809921-24596-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | | Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds2016-02-011-1/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "1/ Fixes to the libnvdimm 'pfn' device that establishes a reserved area for storing a struct page array. 2/ Fixes for dax operations on a raw block device to prevent pagecache collisions with dax mappings. 3/ A fix for pfn_t usage in vm_insert_mixed that lead to a null pointer de-reference. These have received build success notification from the kbuild robot across 153 configs and pass the latest ndctl tests" * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: phys_to_pfn_t: use phys_addr_t mm: fix pfn_t to page conversion in vm_insert_mixed block: use DAX for partition table reads block: revert runtime dax control of the raw block device fs, block: force direct-I/O for dax-enabled block devices devm_memremap_pages: fix vmem_altmap lifetime + alignment handling libnvdimm, pfn: fix restoring memmap location libnvdimm: fix mode determination for e820 devices
| * | | phys_to_pfn_t: use phys_addr_tDan Williams2016-01-311-1/+1
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | A dma_addr_t is potentially smaller than a phys_addr_t on some archs. Don't truncate the address when doing the pfn conversion. Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by: Matthew Wilcox <willy@linux.intel.com> [willy: fix pfn_t_to_phys as well] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | | Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds2016-01-311-1/+138
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "The timer departement delivers: - a regression fix for the NTP code along with a proper selftest - prevent a spurious timer interrupt in the NOHZ lowres code - a fix for user space interfaces returning the remaining time on architectures with CONFIG_TIME_LOW_RES=y - a few patches to fix COMPILE_TEST fallout" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick/nohz: Set the correct expiry when switching to nohz/lowres mode clocksource: Fix dependencies for archs w/o HAS_IOMEM clocksource: Select CLKSRC_MMIO where needed tick/sched: Hide unused oneshot timer code kselftests: timers: Add adjtimex SETOFFSET validity tests ntp: Fix ADJ_SETOFFSET being used w/ ADJ_NANO itimers: Handle relative timers with CONFIG_TIME_LOW_RES proper posix-timers: Handle relative timers with CONFIG_TIME_LOW_RES proper timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper hrtimer: Handle remaining time proper for TIME_LOW_RES clockevents/tcb_clksrc: Prevent disabling an already disabled clock
| * | | kselftests: timers: Add adjtimex SETOFFSET validity testsJohn Stultz2016-01-261-1/+138
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add some simple tests to check both valid and invalid offsets when using adjtimex's ADJ_SETOFFSET method. Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Harald Hoyer <harald@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Cc: David Herrmann <dh.herrmann@gmail.com> Link: http://lkml.kernel.org/r/1453417415-19110-3-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | Merge branches 'clockevents/4.4-fixes' and 'clockevents/4.5-fixes' of ↵Thomas Gleixner2016-01-126-52/+42
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | http://git.linaro.org/people/daniel.lezcano/linux into timers/urgent Pull in fixes from Daniel Lezcano: - Fix the vt8500 timer leading to a system lock up when dealing with too small delta (Roman Volkov) - Select the CLKSRC_MMIO when the fsl_ftm_timer is enabled with COMPILE_TEST (Daniel Lezcano) - Prevent to compile timers using the 'iomem' API when the architecture has not HAS_IOMEM set (Richard Weinberger)
* | \ \ \ Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2016-01-319-22/+75
|\ \ \ \ \ | | |_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "This is much bigger than typical fixes, but Peter found a category of races that spurred more fixes and more debugging enhancements. Work started before the merge window, but got finished only now. Aside of that this contains the usual small fixes to perf and tools. Nothing particular exciting" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits) perf: Remove/simplify lockdep annotation perf: Synchronously clean up child events perf: Untangle 'owner' confusion perf: Add flags argument to perf_remove_from_context() perf: Clean up sync_child_event() perf: Robustify event->owner usage and SMP ordering perf: Fix STATE_EXIT usage perf: Update locking order perf: Remove __free_event() perf/bpf: Convert perf_event_array to use struct file perf: Fix NULL deref perf/x86: De-obfuscate code perf/x86: Fix uninitialized value usage perf: Fix race in perf_event_exit_task_context() perf: Fix orphan hole perf stat: Do not clean event's private stats perf hists: Fix HISTC_MEM_DCACHELINE width setting perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed perf tests: Remove wrong semicolon in while loop in CQM test perf: Synchronously free aux pages in case of allocation failure ...
| * | | | perf stat: Do not clean event's private statsJiri Olsa2016-01-261-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mel reported stddev reporting was broken due to following commit: 106a94a0f8c2 ("perf stat: Introduce read_counters function") This commit merged interval and overall counters reading into single read_counters function. The old interval code cleaned the stddev data for some reason (it's never displayed in interval mode) and the mentioned commit kept on cleaning the stddev data in merged function, which resulted in the stddev not being displayed. Removing the wrong stddev data cleanup init_stats call. Reported-and-Tested-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@vger.kernel.org # v4.2+ Fixes: 106a94a0f8c2 ("perf stat: Introduce read_counters function") Link: http://lkml.kernel.org/r/1453290995-18485-4-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | perf hists: Fix HISTC_MEM_DCACHELINE width settingJiri Olsa2016-01-261-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set correct width for unresolved mem_dcacheline addr. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Fixes: 9b32ba71ba90 ("perf tools: Add dcacheline sort") Link: http://lkml.kernel.org/r/1453290995-18485-3-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | perf annotate browser: Fix behaviour of Shift-Tab with nothing focussedMarkus Trippelsdorf2016-01-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The issue was pointed out by gcc-6's -Wmisleading-indentation. Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: c97cf42219b7 ("perf top: Live TUI Annotation") Link: http://lkml.kernel.org/r/20151214154403.GB1409@x4 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | perf tests: Remove wrong semicolon in while loop in CQM testMarkus Trippelsdorf2016-01-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The while loop was spinning. Fix by removing a semicolon. The issue was pointed out by gcc-6's -Wmisleading-indentation. Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: 035827e9f2bd ("perf tests: Add Intel CQM test") Link: http://lkml.kernel.org/r/20151214154335.GA1409@x4 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | Merge tag 'perf-core-for-mingo' of ↵Ingo Molnar2016-01-195-18/+70
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf tools improvements and fixes from Arnaldo Carvalho de Melo: User visible bug fixes: - Fix reading of build-id from vDSO (Ben Hutchings) - Fix processing samples for guests, noticed with 'perf kvm', but noticeable as well via other tools, such as 'perf top' (Ravi Bangoria) Build infrastructure: - Add feature-dump target and FEATURES_DUMP make variable, to allow reusing the feature detection results among multiple tools/ living codebases, such as perf and lib/bpf (Jiri Olsa) - 'make -C tools/perf build-test' improvements, making it more paralelizable and allowing building it outside of the source tree, using O= (Wang Nan) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | perf build: Introduce FEATURES_DUMP make variableJiri Olsa2016-01-152-1/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introducing FEATURES_DUMP make variable to provide features detection dump file and bypass the feature detection. The intention is to use this during build tests to skip repeated features detection, like: Get feature dump static build into /tmp/fd file: $ make feature-dump FEATURE_DUMP_COPY=/tmp/fd LDFLAGS=-static BUILD: Doing 'make -j4' parallel build Auto-detecting system features: ... dwarf: [ OFF ] SNIP FEATURE-DUMP file copied into /tmp/fd Use /tmp/fd to build perf: $ make FEATURES_DUMP=/tmp/fd LDFLAGS=-static $ file perf perf: ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically linked, for ... Suggested-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1452830421-77757-7-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | perf build: Add feature-dump targetJiri Olsa2016-01-151-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To provide FEATURE-DUMP into $(FEATURE_DUMP_COPY) if defined, with no further action. Get feature dump of the current build: $ make feature-dump BUILD: Doing 'make -j4' parallel build Auto-detecting system features: ... dwarf: [ on ] FEATURE-DUMP file available in FEATURE-DUMP Get feature dump static build into /tmp/fd file: $ make feature-dump FEATURE_DUMP_COPY=/tmp/fd LDFLAGS=-static BUILD: Doing 'make -j4' parallel build Auto-detecting system features: ... dwarf: [ OFF ] SNIP FEATURE-DUMP file copied into /tmp/fd Suggested-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1452830421-77757-6-git-send-email-wangnan0@huawei.com Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | perf build: Pass O option to kernel makefile in build-testWang Nan2016-01-151-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kernel makefile only follows an 'O' option passed from command line explicitely. In build-test with 'O' option set, kernel makefile contaminate kernel source directory. Build test also fail if we don't create output directory manually. K_O_OPT is added and passed to kernel makefile if 'O' is passed to build-test. Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1452830421-77757-5-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | perf build: Test correct path of perf in build-testWang Nan2016-01-151-7/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If an 'O' is passed to 'make build-test', many 'test -x' and 'test -f' will fail because perf resides in a different directory. Fix this by computing PERF_OUT according to 'O' and test correct output files. For make_kernelsrc and make_kernelsrc_tools, set KBUILD_OUTPUT_DIR instead because the path is different from others ($(O)/perf vs $(O)/tools/perf). Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1452830421-77757-4-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | perf build: Pass O option to Makefile.perf in build-testWang Nan2016-01-151-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unlike tools/perf/Makefile, tools/perf/Makefile.perf obey 'O' option when it is passed through cmdline only, due to code in tools/scripts/Makefile.include: ifneq ($(O),) ifeq ($(origin O), command line) ... ABSOLUTE_O := $(shell cd $(O) ; pwd) OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/) endif endif This patch passes 'O' to Makefile.perf through cmdline explicitly to make it follow O variable during build-test. 'make clean' should have identical 'O' option with 'make'. If not, config-clean may error. Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1452830421-77757-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | perf build: Set parallel making options build-testWang Nan2016-01-151-7/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'make build-test' is painful because of time consuming. In a full test, all test cases are built twice with tools/perf/Makefile and tools/perf/Makefile.perf. 'Makefile' automatically computes parallel options for make, but 'Makefile.perf' not, so all test cases is built with one job. It is very slow. This patch adds '-j' options to Makefile.perf testing. It computes parallel building options like what tools/perf/Makefile does, and pass '-j' option to Makefile.perf test. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1452687442-6186-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | perf symbols: Fix reading of build-id from vDSOBen Hutchings2016-01-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to use the long name (the filename) when reading the build-id from a DSO. Using the short name doesn't work for (at least) vDSOs. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20160113172301.GT28542@decadent.org.uk Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | perf kvm record/report: 'unprocessable sample' error while ↵Ravi Bangoria2016-01-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | recording/reporting guest data While recording guest samples in host using perf kvm record, it will populate unprocessable sample error, though samples will be recorded properly. While generating report using perf kvm report, no samples will be processed and same error will populate. We have seen this behaviour with upstream perf(4.4-rc3) on x86 and ppc64 hardware. Reason behind this failure is, when it tries to fetch machine from rb_tree of machines, it fails. As a part of tracing a bug, we figured out that this code was incorrectly refactored in commit 54245fdc3576 ("perf session: Remove wrappers to machines__find"). This patch will change the functionality such that if it can't fetch machine in first trial, it will create one node of machine and add that to rb_tree. So next time when it tries to fetch same machine from rb_tree, it won't fail. Actually it was the case before refactoring of code in aforementioned commit. This patch is generated from acme perf/core branch. Below I've mention an example that demonstrate the behaviour before and after applying patch. Before applying patch: [Note: One needs to run guest before recording data in host] ravi@ravi-bangoria:~$ ./perf kvm record -a Warning: 5903 unprocessable samples recorded. Do you have a KVM guest running and not using 'perf kvm'? [ perf record: Captured and wrote 1.409 MB perf.data.guest (285 samples) ] ravi@ravi-bangoria:~$ ./perf kvm report --stdio Warning: 5903 unprocessable samples recorded. Do you have a KVM guest running and not using 'perf kvm'? # To display the perf.data header info, please use --header/--header-only options. # # Total Lost Samples: 0 # # Samples: 285 of event 'cycles' # Event count (approx.): 88715406 # # Overhead Command Shared Object Symbol # ........ ....... ............. ...... # # (For a higher level overview, try: perf report --sort comm,dso) # After applying patch: ravi@ravi-bangoria:~$ ./perf kvm record -a [ perf record: Captured and wrote 1.188 MB perf.data.guest (17 samples) ] ravi@ravi-bangoria:~$ ./perf kvm report --stdio # To display the perf.data header info, please use --header/--header-only options. # # Total Lost Samples: 0 # # Samples: 17 of event 'cycles' # Event count (approx.): 700746 # # Overhead Command Shared Object Symbol # ........ ....... ................ ...................... # 34.19% :5758 [unknown] [g] 0xffffffff818682ab 22.79% :5758 [unknown] [g] 0xffffffff812dc7f8 22.79% :5758 [unknown] [g] 0xffffffff818650d0 14.83% :5758 [unknown] [g] 0xffffffff8161a1b6 2.49% :5758 [unknown] [g] 0xffffffff818692bf 0.48% :5758 [unknown] [g] 0xffffffff81869253 0.05% :5758 [unknown] [g] 0xffffffff81869250 Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # v3.19+ Fixes: 54245fdc3576 ("perf session: Remove wrappers to machines__find") Link: http://lkml.kernel.org/r/1449471302-11283-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
generated by cgit v1.2.3 (git 2.25.1) at 2025-02-05 05:28:45 +0000