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2018-12-17objtool: Fix segfault in .cold detection with -ffunction-sectionsArtem Savkov
[ Upstream commit 22566c1603030f0a036ad564634b064ad1a55db2 ] Because find_symbol_by_name() traverses the same lists as read_symbols(), changing sym->name in place without copying it affects the result of find_symbol_by_name(). In the case where a ".cold" function precedes its parent in sec->symbol_list, it can result in a function being considered a parent of itself. This leads to function length being set to 0 and other consequent side-effects including a segfault in add_switch_table(). The effects of this bug are only visible when building with -ffunction-sections in KCFLAGS. Fix by copying the search string instead of modifying it in place. Signed-off-by: Artem Savkov <asavkov@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 13810435b9a7 ("objtool: Support GCC 8's cold subfunctions") Link: http://lkml.kernel.org/r/910abd6b5a4945130fd44f787c24e07b9e07c8da.1542736240.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-17objtool: Fix double-free in .cold detection error pathArtem Savkov
[ Upstream commit 0b9301fb632f7111a3293a30cc5b20f1b82ed08d ] If read_symbols() fails during second list traversal (the one dealing with ".cold" subfunctions) it frees the symbol, but never deletes it from the list/hash_table resulting in symbol being freed again in elf_close(). Fix it by just returning an error, leaving cleanup to elf_close(). Signed-off-by: Artem Savkov <asavkov@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 13810435b9a7 ("objtool: Support GCC 8's cold subfunctions") Link: http://lkml.kernel.org/r/beac5a9b7da9e8be90223459dcbe07766ae437dd.1542736240.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-08-24objtool: Support GCC 8 '-fnoreorder-functions'Josh Poimboeuf
[ Upstream commit 08b393d01c88aff27347ed2b1b354eb4db2f1532 ] Since the following commit: cd77849a69cf ("objtool: Fix GCC 8 cold subfunction detection for aliased functions") ... if the kernel is built with EXTRA_CFLAGS='-fno-reorder-functions', objtool can get stuck in an infinite loop. That flag causes the new GCC 8 cold subfunctions to be placed in .text instead of .text.unlikely. But it also has an unfortunate quirk: in the symbol table, the subfunction (e.g., nmi_panic.cold.7) is nested inside the parent (nmi_panic). That function overlap confuses objtool, and causes it to get into an infinite loop in next_insn_same_func(). Here's Allan's description of the loop: "Objtool iterates through the instructions in nmi_panic using next_insn_same_func. Once it reaches the end of nmi_panic at 0x534 it jumps to 0x528 as that's the start of nmi_panic.cold.7. However, since the instructions starting at 0x528 are still associated with nmi_panic objtool will get stuck in a loop, continually jumping back to 0x528 after reaching 0x534." Fix it by shortening the length of the parent function so that the functions no longer overlap. Reported-and-analyzed-by: Allan Xavier <allan.x.xavier@oracle.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Allan Xavier <allan.x.xavier@oracle.com> Cc: Andy Lutomirski <luto@kernel.org> 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: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/9e704c52bee651129b036be14feda317ae5606ae.1530136978.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-11Kbuild: fix # escaping in .cmd files for future MakeRasmus Villemoes
commit 9564a8cf422d7b58f6e857e3546d346fa970191e upstream. I tried building using a freshly built Make (4.2.1-69-g8a731d1), but already the objtool build broke with orc_dump.c: In function ‘orc_dump’: orc_dump.c:106:2: error: ‘elf_getshnum’ is deprecated [-Werror=deprecated-declarations] if (elf_getshdrnum(elf, &nr_sections)) { Turns out that with that new Make, the backslash was not removed, so cpp didn't see a #include directive, grep found nothing, and -DLIBELF_USE_DEPRECATED was wrongly put in CFLAGS. Now, that new Make behaviour is documented in their NEWS file: * WARNING: Backward-incompatibility! Number signs (#) appearing inside a macro reference or function invocation no longer introduce comments and should not be escaped with backslashes: thus a call such as: foo := $(shell echo '#') is legal. Previously the number sign needed to be escaped, for example: foo := $(shell echo '\#') Now this latter will resolve to "\#". If you want to write makefiles portable to both versions, assign the number sign to a variable: C := \# foo := $(shell echo '$C') This was claimed to be fixed in 3.81, but wasn't, for some reason. To detect this change search for 'nocomment' in the .FEATURES variable. This also fixes up the two make-cmd instances to replace # with $(pound) rather than with \#. There might very well be other places that need similar fixup in preparation for whatever future Make release contains the above change, but at least this builds an x86_64 defconfig with the new make. Link: https://bugzilla.kernel.org/show_bug.cgi?id=197847 Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-26objtool: update .gitignore fileGreg Kroah-Hartman
With the recent sync with objtool from 4.14.y, the objtool .gitignore file was forgotten. Fix that up now to properly handle the change in where the autogenerated files live. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05objtool: header file sync-upGreg Kroah-Hartman
When building tools/objtool/ it rightly complains about a number of files being out of sync. Fix this up by syncing them properly with the relevant in-kernel versions. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05objtool: Fix "noreturn" detection for recursive sibling callsJosh Poimboeuf
commit 0afd0d9e0e7879d666c1df2fa1bea4d8716909fe upstream. Objtool has some crude logic for detecting static "noreturn" functions (aka "dead ends"). This is necessary for being able to correctly follow GCC code flow when such functions are called. It's remotely possible for two functions to call each other via sibling calls. If they don't have RET instructions, objtool's noreturn detection logic goes into a recursive loop: drivers/char/ipmi/ipmi_ssif.o: warning: objtool: return_hosed_msg()+0x0: infinite recursion (objtool bug!) drivers/char/ipmi/ipmi_ssif.o: warning: objtool: deliver_recv_msg()+0x0: infinite recursion (objtool bug!) Instead of reporting an error in this case, consider the functions to be non-dead-ends. Reported-and-tested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: damian <damian.tometzki@icloud.com> Link: http://lkml.kernel.org/r/7cc156408c5781a1f62085d352ced1fe39fe2f91.1525923412.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05objtool: Detect RIP-relative switch table references, part 2Josh Poimboeuf
commit 7dec80ccbe310fb7e225bf21c48c672bb780ce7b upstream. With the following commit: fd35c88b7417 ("objtool: Support GCC 8 switch tables") I added a "can't find switch jump table" warning, to stop covering up silent failures if add_switch_table() can't find anything. That warning found yet another bug in the objtool switch table detection logic. For cases 1 and 2 (as described in the comments of find_switch_table()), the find_symbol_containing() check doesn't adjust the offset for RIP-relative switch jumps. Incidentally, this bug was already fixed for case 3 with: 6f5ec2993b1f ("objtool: Detect RIP-relative switch table references") However, that commit missed the fix for cases 1 and 2. The different cases are now starting to look more and more alike. So fix the bug by consolidating them into a single case, by checking the original dynamic jump instruction in the case 3 loop. This also simplifies the code and makes it more robust against future switch table detection issues -- of which I'm sure there will be many... Switch table detection has been the most fragile area of objtool, by far. I long for the day when we'll have a GCC plugin for annotating switch tables. Linus asked me to delay such a plugin due to the flakiness of the plugin infrastructure in older versions of GCC, so this rickety code is what we're stuck with for now. At least the code is now a little simpler than it was. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.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/f400541613d45689086329432f3095119ffbc328.1526674218.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05objtool: Detect RIP-relative switch table referencesJosh Poimboeuf
commit 6f5ec2993b1f39aed12fa6fd56e8dc2272ee8a33 upstream. Typically a switch table can be found by detecting a .rodata access followed an indirect jump: 1969: 4a 8b 0c e5 00 00 00 mov 0x0(,%r12,8),%rcx 1970: 00 196d: R_X86_64_32S .rodata+0x438 1971: e9 00 00 00 00 jmpq 1976 <dispc_runtime_suspend+0xb6a> 1972: R_X86_64_PC32 __x86_indirect_thunk_rcx-0x4 Randy Dunlap reported a case (seen with GCC 4.8) where the .rodata access uses RIP-relative addressing: 19bd: 48 8b 3d 00 00 00 00 mov 0x0(%rip),%rdi # 19c4 <dispc_runtime_suspend+0xbb8> 19c0: R_X86_64_PC32 .rodata+0x45c 19c4: e9 00 00 00 00 jmpq 19c9 <dispc_runtime_suspend+0xbbd> 19c5: R_X86_64_PC32 __x86_indirect_thunk_rdi-0x4 In this case the relocation addend needs to be adjusted accordingly in order to find the location of the switch table. The fix is for case 3 (as described in the comments), but also make the existing case 1 & 2 checks more precise by only adjusting the addend for R_X86_64_PC32 relocations. This fixes the following warnings: drivers/video/fbdev/omap2/omapfb/dss/dispc.o: warning: objtool: dispc_runtime_suspend()+0xbb8: sibling call from callable instruction with modified stack frame drivers/video/fbdev/omap2/omapfb/dss/dispc.o: warning: objtool: dispc_runtime_resume()+0xcc5: sibling call from callable instruction with modified stack frame Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.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/b6098294fd67afb69af8c47c9883d7a68bf0f8ea.1526305958.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05objtool: Support GCC 8 switch tablesJosh Poimboeuf
commit fd35c88b74170d9335530d9abf271d5d73eb5401 upstream. With GCC 8, some issues were found with the objtool switch table detection. 1) In the .rodata section, immediately after the switch table, there can be another object which contains a pointer to the function which had the switch statement. In this case objtool wrongly considers the function pointer to be part of the switch table. Fix it by: a) making sure there are no pointers to the beginning of the function; and b) making sure there are no gaps in the switch table. Only the former was needed, the latter adds additional protection for future optimizations. 2) In find_switch_table(), case 1 and case 2 are missing the check to ensure that the .rodata switch table data is anonymous, i.e. that it isn't already associated with an ELF symbol. Fix it by adding the same find_symbol_containing() check which is used for case 3. This fixes the following warnings with GCC 8: drivers/block/virtio_blk.o: warning: objtool: virtio_queue_rq()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+72 net/ipv6/icmp.o: warning: objtool: icmpv6_rcv()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+64 drivers/usb/core/quirks.o: warning: objtool: quirks_param_set()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+48 drivers/mtd/nand/raw/nand_hynix.o: warning: objtool: hynix_nand_decode_id()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+24 drivers/mtd/nand/raw/nand_samsung.o: warning: objtool: samsung_nand_decode_id()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+32 drivers/gpu/drm/nouveau/nvkm/subdev/top/gk104.o: warning: objtool: gk104_top_oneinit()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+64 Reported-by: Arnd Bergmann <arnd@arndb.de> Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: damian <damian.tometzki@icloud.com> Link: http://lkml.kernel.org/r/20180510224849.xwi34d6tzheb5wgw@treble Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05objtool: Support GCC 8's cold subfunctionsJosh Poimboeuf
commit 13810435b9a7014fb92eb715f77da488f3b65b99 upstream. GCC 8 moves a lot of unlikely code out of line to "cold" subfunctions in .text.unlikely. Properly detect the new subfunctions and treat them as extensions of the original functions. This fixes a bunch of warnings like: kernel/cgroup/cgroup.o: warning: objtool: parse_cgroup_root_flags()+0x33: sibling call from callable instruction with modified stack frame kernel/cgroup/cgroup.o: warning: objtool: cgroup_addrm_files()+0x290: sibling call from callable instruction with modified stack frame kernel/cgroup/cgroup.o: warning: objtool: cgroup_apply_control_enable()+0x25b: sibling call from callable instruction with modified stack frame kernel/cgroup/cgroup.o: warning: objtool: rebind_subsystems()+0x325: sibling call from callable instruction with modified stack frame Reported-and-tested-by: damian <damian.tometzki@icloud.com> Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/0965e7fcfc5f31a276f0c7f298ff770c19b68706.1525923412.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05objtool: sync up with the 4.14.47 version of objtoolGreg Kroah-Hartman
There are pros and cons of dealing with tools in the kernel directory. The pros are the fact that development happens fast, and new features can be added to the kernel and the tools at the same times. The cons are when dealing with backported kernel patches, it can be necessary to backport parts of the tool changes as well. For 4.9.y so far, we have backported individual patches. That quickly breaks down when there are minor differences between how backports were handled, so grabbing 40+ patch long series can be difficult, not impossible, but really frustrating to attempt. To help mitigate this mess, here's a single big patch to sync up the objtool logic to the 4.14.47 version of the tool. From this point forward (after some other minor header file patches are applied), the tool should be in sync and much easier to maintain over time. This has survivied my limited testing, and as the codebase is identical to 4.14.47, I'm pretty comfortable dropping this big change in here in 4.9.y. Hopefully all goes well... Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05objtool: Move checking code to check.cJosh Poimboeuf
commit dcc914f44f065ef73685b37e59877a5bb3cb7358 upstream. In preparation for the new 'objtool undwarf generate' command, which will rely on 'objtool check', move the checking code from builtin-check.c to check.c where it can be used by other commands. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Jiri Slaby <jslaby@suse.cz> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/294c5c695fd73c1a5000bbe5960a7c9bec4ee6b4.1498659915.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> [backported by hand to 4.9, this was a pain... - gregkh] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-05objtool: Improve detection of BUG() and other dead endsJosh Poimboeuf
commit d1091c7fa3d52ebce4dd3f15d04155b3469b2f90 upstream. The BUG() macro's use of __builtin_unreachable() via the unreachable() macro tells gcc that the instruction is a dead end, and that it's safe to assume the current code path will not execute past the previous instruction. On x86, the BUG() macro is implemented with the 'ud2' instruction. When objtool's branch analysis sees that instruction, it knows the current code path has come to a dead end. Peter Zijlstra has been working on a patch to change the WARN macros to use 'ud2'. That patch will break objtool's assumption that 'ud2' is always a dead end. Generally it's best for objtool to avoid making those kinds of assumptions anyway. The more ignorant it is of kernel code internals, the better. So create a more generic way for objtool to detect dead ends by adding an annotation to the unreachable() macro. The annotation stores a pointer to the end of the unreachable code path in an '__unreachable' section. Objtool can read that section to find the dead ends. Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.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/41a6d33971462ebd944a1c60ad4bf5be86c17b77.1487712920.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-23objtool: Improve error message for bad file argumentJosh Poimboeuf
commit 385d11b152c4eb638eeb769edcb3249533bb9a00 upstream. If a nonexistent file is supplied to objtool, it complains with a non-helpful error: open: No such file or directory Improve it to: objtool: Can't open 'foo': No such file or directory Reported-by: Markus <M4rkusXXL@web.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.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/406a3d00a21225eee2819844048e17f68523ccf6.1516025651.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17objtool: Fix retpoline support for pre-ORC objtoolJosh Poimboeuf
Objtool 1.0 (pre-ORC) produces the following warning when it encounters a retpoline: arch/x86/crypto/camellia-aesni-avx2-asm_64.o: warning: objtool: .altinstr_replacement+0xf: return instruction outside of a callable function That warning is meant to catch GCC bugs and missing ENTRY/ENDPROC annotations, neither of which are applicable to alternatives. Silence the warning for alternative instructions, just like objtool 2.0 already does. Reported-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17objtool: Allow alternatives to be ignoredJosh Poimboeuf
commit 258c76059cece01bebae098e81bacb1af2edad17 upstream. Getting objtool to understand retpolines is going to be a bit of a challenge. For now, take advantage of the fact that retpolines are patched in with alternatives. Just read the original (sane) non-alternative instruction, and ignore the patched-in retpoline. This allows objtool to understand the control flow *around* the retpoline, even if it can't yet follow what's inside. This means the ORC unwinder will fail to unwind from inside a retpoline, but will work fine otherwise. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: thomas.lendacky@amd.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1515707194-20531-3-git-send-email-dwmw@amazon.co.uk [dwmw2: Applies to tools/objtool/builtin-check.c not check.[ch]] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17objtool: Detect jumps to retpoline thunksJosh Poimboeuf
commit 39b735332cb8b33a27c28592d969e4016c86c3ea upstream. A direct jump to a retpoline thunk is really an indirect jump in disguise. Change the objtool instruction type accordingly. Objtool needs to know where indirect branches are so it can detect switch statement jump tables. This fixes a bunch of warnings with CONFIG_RETPOLINE like: arch/x86/events/intel/uncore_nhmex.o: warning: objtool: nhmex_rbox_msr_enable_event()+0x44: sibling call from callable instruction with modified stack frame kernel/signal.o: warning: objtool: copy_siginfo_to_user()+0x91: sibling call from callable instruction with modified stack frame ... Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: thomas.lendacky@amd.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1515707194-20531-2-git-send-email-dwmw@amazon.co.uk [dwmw2: Applies to tools/objtool/builtin-check.c not check.c] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17objtool, modules: Discard objtool annotation sections for modulesJosh Poimboeuf
commit e390f9a9689a42f477a6073e2e7df530a4c1b740 upstream. The '__unreachable' and '__func_stack_frame_non_standard' sections are only used at compile time. They're discarded for vmlinux but they should also be discarded for modules. Since this is a recurring pattern, prefix the section names with ".discard.". It's a nice convention and vmlinux.lds.h already discards such sections. Also remove the 'a' (allocatable) flag from the __unreachable section since it doesn't make sense for a discarded section. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jessica Yu <jeyu@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends") Link: http://lkml.kernel.org/r/20170301180444.lhd53c5tibc4ns77@treble Signed-off-by: Ingo Molnar <mingo@kernel.org> [dwmw2: Remove the unreachable part in backporting since it's not here yet] Signed-off-by: David Woodhouse <dwmw@amazon.co.ku> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02sync objtool's copy of x86-opcode-map.txtGreg Kroah-Hartman
When building objtool, we get the warning: warning: objtool: x86 instruction decoder differs from kernel That's due to commit 2816c0455cea088f07a210f8a00701a82a78aa9c which was commit 12a78d43de767eaf8fb272facb7a7b6f2dc6a9df upstream that modified arch/x86/lib/x86-opcode-map.txt without also updating the objtool copy. The objtool copy was updated in a much larger patch upstream, but we don't need all of that here, so just update the single file. If this gets too annoying, I'll just end up doing what we did for 4.14 and backport the whole series to keep this from happening again, but as this seems to be rare in the 4.9-stable series, this single patch should be fine. Cc: Masami Hiramatsu <mhiramat@kernel.org> 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> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05objtool: Fix another GCC jump table detection issueJosh Poimboeuf
commit 5c51f4ae84df0f9df33ac08aa5be50061a8b4242 upstream. Arnd Bergmann reported a (false positive) objtool warning: drivers/infiniband/sw/rxe/rxe_resp.o: warning: objtool: rxe_responder()+0xfe: sibling call from callable instruction with changed frame pointer The issue is in find_switch_table(). It tries to find a switch statement's jump table by walking backwards from an indirect jump instruction, looking for a relocation to the .rodata section. In this case it stopped walking prematurely: the first .rodata relocation it encountered was for a variable (resp_state_name) instead of a jump table, so it just assumed there wasn't a jump table. The fix is to ignore any .rodata relocation which refers to an ELF object symbol. This works because the jump tables are anonymous and have no symbols associated with them. Reported-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 3732710ff6f2 ("objtool: Improve rare switch jump table pattern detection") Link: http://lkml.kernel.org/r/20170302225723.3ndbsnl4hkqbne7a@treble Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05objtool: Fix IRET's opcodeJiri Slaby
[ Upstream commit b5b46c4740aed1538544f0fa849c5b76c7823469 ] The IRET opcode is 0xcf according to the Intel manual and also to objdump of my vmlinux: 1ea8: 48 cf iretq Fix the opcode in arch_decode_instruction(). The previous value (0xc5) seems to correspond to LDS. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170118132921.19319-1-jslaby@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-06objtool: Fix bytes check of lea's rex_prefixJiri Slaby
For the "lea %(rsp), %rbp" case, we check if there is a rex_prefix. But we check 'bytes' which is insn_byte_t[4] in rex_prefix (insn_field structure). Therefore, the check is always true. Instead, check 'nbytes' which is the right one. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161205105551.25917-1-jslaby@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-27objtool: Fix rare switch jump table pattern detectionJosh Poimboeuf
The following commit: 3732710ff6f2 ("objtool: Improve rare switch jump table pattern detection") ... improved objtool's ability to detect GCC switch statement jump tables for GCC 6. However the check to allow short jumps with the scanned range of instructions wasn't quite right. The pattern detection should allow jumps to the indirect jump instruction itself. This fixes the following warning: drivers/infiniband/sw/rxe/rxe_comp.o: warning: objtool: rxe_completer()+0x315: sibling call from callable instruction with changed frame pointer Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 3732710ff6f2 ("objtool: Improve rare switch jump table pattern detection") Link: http://lkml.kernel.org/r/20161026153408.2rifnw7bvoc5sex7@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-16objtool: Skip all "unreachable instruction" warnings for gcov kernelsJosh Poimboeuf
Recently objtool has started reporting a few "unreachable instruction" warnings when CONFIG_GCOV is enabled for newer versions of GCC. Usually this warning means there's some new control flow that objtool doesn't understand. But in this case, objtool is correct and the instructions really are inaccessible. It's an annoying quirk of gcov, but it's harmless, so it's ok to just silence the warnings. With older versions of GCC, it was relatively easy to detect gcov-specific instructions and to skip any unreachable warnings produced by them. But GCC 6 has gotten craftier. Instead of continuing to play whack-a-mole with gcov, just use a bigger, more permanent hammer and disable unreachable warnings for the whole file when gcov is enabled. This is fine to do because a) unreachable warnings are usually of questionable value; and b) gcov isn't used for production kernels and we can relax the checks a bit there. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> 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: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/38d5c87d61d9cd46486dd2c86f46603dff0df86f.1476393584.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-16objtool: Improve rare switch jump table pattern detectionJosh Poimboeuf
GCC 6 added a new switch statement jump table optimization which makes objtool's life harder. It looks like: mov [rodata addr],%reg1 ... some instructions ... jmpq *(%reg1,%reg2,8) The optimization is quite rare, but objtool still needs to be able to identify the pattern so that it can follow all possible control flow paths related to the switch statement. In order to detect the pattern, objtool starts from the indirect jump and scans backwards through the function until it finds the first instruction in the pattern. If it encounters an unconditional jump along the way, it stops and considers the pattern to be not found. As it turns out, unconditional jumps can happen, as long as they are small forward jumps within the range being scanned. This fixes the following warnings: drivers/infiniband/sw/rxe/rxe_comp.o: warning: objtool: rxe_completer()+0x2f4: sibling call from callable instruction with changed frame pointer drivers/infiniband/sw/rxe/rxe_resp.o: warning: objtool: rxe_responder()+0x10f: sibling call from callable instruction with changed frame pointer Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8a9ed68ae1780e8d3963e4ee13f2f257fe3a3c33.1476393584.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-11objtool: Support '-mtune=atom' stack frame setup instructionJosh Poimboeuf
Arnd reported that enabling CONFIG_MATOM results in a bunch of objtool false positive frame pointer warnings: arch/x86/events/intel/ds.o: warning: objtool: intel_pmu_pebs_del()+0x43: call without frame pointer save/setup security/keys/keyring.o: warning: objtool: keyring_read()+0x59: call without frame pointer save/setup kernel/signal.o: warning: objtool: __dequeue_signal()+0xd8: call without frame pointer save/setup ... objtool gets confused by the fact that the '-mtune=atom' GCC option sometimes uses 'lea (%rsp),%rbp' instead of 'mov %rsp,%rbp'. The instructions are effectively the same, but objtool doesn't know about the 'lea' variant. Fix the false warnings by adding support for 'lea (%rsp),%rbp' in the objtool decoder. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-23objtool: Add do_task_dead() to global noreturn listJosh Poimboeuf
objtool reports the following new warning: kernel/exit.o: warning: objtool: do_exit() falls through to next function complete_and_exit() The warning is caused by do_exit()'s new call to do_task_dead(), which is a new "noreturn" function which objtool doesn't know about yet, introduced by: 9af6528ee9b6 ("sched/core: Optimize __schedule()") ( objtool has to know all the global noreturn functions so it can follow the control flow of any functions which call them. Unfortunately they need to be hard-coded because there's no automated way to detect them. ) Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kbuild-all@01.org Cc: tipbuild@zytor.com Link: http://lkml.kernel.org/r/20160922212125.zbuewckqll4yur25@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-30Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc fixes from Thomas Gleixner: "This update contains: - a fix for stomp-machine so the nmi_watchdog wont trigger on the cpu waiting for the others to execute the callback - various fixes and updates to objtool including an resync of the instruction decoder to match the kernel's decoder" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Un-capitalize "Warning" for out-of-sync instruction decoder objtool: Resync x86 instruction decoder with the kernel's objtool: Support new GCC 6 switch jump table pattern stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE objtool: Add 'fixdep' to objtool/.gitignore
2016-07-29objtool: Un-capitalize "Warning" for out-of-sync instruction decoderJosh Poimboeuf
Change "Warning" to "warning" to make it look more like a GCC warning. Hopefully that will be enough to help the 0-day bot or other automated tools catch this warning earlier before it ends up in Linus's tree. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/b1669f391a5db91040427fd9f8e1e79db18f9709.1469751119.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-29objtool: Resync x86 instruction decoder with the kernel'sJosh Poimboeuf
This fixes the following warning: Warning: objtool: x86 instruction decoder differs from kernel Unfortunately we have three identical copies of the x86 instruction decoder in the kernel tree that have to be manually kept in sync. It's on my TODO list to at least library-ize the ones in the tools subdir so we'd only have two of them instead of three. In the meantime, here's another manual sync. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: c61f4d5ebaf0 ("perf tools: Add AVX-512 support to the instruction decoder used by Intel PT") Link: http://lkml.kernel.org/r/d7f74b4d91fed25b0be33cd5c86f5131fa1a7529.1469751119.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-29objtool: Support new GCC 6 switch jump table patternJosh Poimboeuf
This fixes some false positive objtool warnings seen with gcc 6.1.1: kernel/trace/ring_buffer.o: warning: objtool: ring_buffer_read_page()+0x36c: sibling call from callable instruction with changed frame pointer arch/x86/kernel/reboot.o: warning: objtool: native_machine_emergency_restart()+0x139: sibling call from callable instruction with changed frame pointer lib/xz/xz_dec_stream.o: warning: objtool: xz_dec_run()+0xc2: sibling call from callable instruction with changed frame pointer With GCC 6, a new code pattern is sometimes used to access a switch statement jump table in .rodata, which objtool doesn't yet recognize: mov [rodata addr],%reg1 ... some instructions ... jmpq *(%reg1,%reg2,8) Add support for detecting that pattern. The detection code is rather crude, but it's still effective at weeding out false positives and catching real warnings. It can be refined later once objtool starts reading DWARF CFI. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/b8c9503b4ad8c8a827cc5400db4c1b40a3ea07bc.1469751119.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-28Merge tag 'libnvdimm-for-4.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: - Replace pcommit with ADR / directed-flushing. The pcommit instruction, which has not shipped on any product, is deprecated. Instead, the requirement is that platforms implement either ADR, or provide one or more flush addresses per nvdimm. ADR (Asynchronous DRAM Refresh) flushes data in posted write buffers to the memory controller on a power-fail event. Flush addresses are defined in ACPI 6.x as an NVDIMM Firmware Interface Table (NFIT) sub-structure: "Flush Hint Address Structure". A flush hint is an mmio address that when written and fenced assures that all previous posted writes targeting a given dimm have been flushed to media. - On-demand ARS (address range scrub). Linux uses the results of the ACPI ARS commands to track bad blocks in pmem devices. When latent errors are detected we re-scrub the media to refresh the bad block list, userspace can also request a re-scrub at any time. - Support for the Microsoft DSM (device specific method) command format. - Support for EDK2/OVMF virtual disk device memory ranges. - Various fixes and cleanups across the subsystem. * tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (41 commits) libnvdimm-btt: Delete an unnecessary check before the function call "__nd_device_register" nfit: do an ARS scrub on hitting a latent media error nfit: move to nfit/ sub-directory nfit, libnvdimm: allow an ARS scrub to be triggered on demand libnvdimm: register nvdimm_bus devices with an nd_bus driver pmem: clarify a debug print in pmem_clear_poison x86/insn: remove pcommit Revert "KVM: x86: add pcommit support" nfit, tools/testing/nvdimm/: unify shutdown paths libnvdimm: move ->module to struct nvdimm_bus_descriptor nfit: cleanup acpi_nfit_init calling convention nfit: fix _FIT evaluation memory leak + use after free tools/testing/nvdimm: add manufacturing_{date|location} dimm properties tools/testing/nvdimm: add virtual ramdisk range acpi, nfit: treat virtual ramdisk SPA as pmem region pmem: kill __pmem address space pmem: kill wmb_pmem() libnvdimm, pmem: use nvdimm_flush() for namespace I/O writes fs/dax: remove wmb_pmem() libnvdimm, pmem: flush posted-write queues on shutdown ...
2016-07-27objtool: Add 'fixdep' to objtool/.gitignorePaul Gortmaker
To fix: Untracked files: (use "git add <file>..." to include in what will be committed) tools/objtool/fixdep Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.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/a4571f6893caf737d05524cfa3829c2abc1fb240.1469452729.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-26Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This tree contains tooling fixes plus some additions: - fixes to the vdso2c build environment that Stephen Rothwell is using for the linux-next build (Arnaldo Carvalho de Melo) - AVX-512 instruction mappings (Adrian Hunter) - misc fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Revert "perf tools: event.h needs asm/perf_regs.h" x86: Make the vdso2c compiler use the host architecture headers tools build: Fix objtool build with ARCH=x86_64 objtool: Always use host headers objtool: Use tools/scripts/Makefile.arch to get ARCH and HOSTARCH tools build: Add HOSTARCH Makefile variable perf tests kmod-path: Fix build on ubuntu:16.04-x-armhf perf tools: Add AVX-512 instructions to the new instructions test perf tools: Add AVX-512 support to the instruction decoder used by Intel PT x86/insn: Add AVX-512 support to the instruction decoder x86/insn: perf tools: Fix vcvtph2ps instruction decoding
2016-07-25Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "With over 300 commits it's been a busy cycle - with most of the work concentrated on the tooling side (as it should). The main kernel side enhancements were: - Add per event callchain limit: Recently we introduced a sysctl to tune the max-stack for all events for which callchains were requested: $ sysctl kernel.perf_event_max_stack kernel.perf_event_max_stack = 127 Now this patch introduces a way to configure this per event, i.e. this becomes possible: $ perf record -e sched:*/max-stack=2/ -e block:*/max-stack=10/ -a allowing finer tuning of how much buffer space callchains use. This uses an u16 from the reserved space at the end, leaving another u16 for future use. There has been interest in even finer tuning, namely to control the max stack for kernel and userspace callchains separately. Further discussion is needed, we may for instance use the remaining u16 for that and when it is present, assume that the sample_max_stack introduced in this patch applies for the kernel, and the u16 left is used for limiting the userspace callchain (Arnaldo Carvalho de Melo) - Optimize AUX event (hardware assisted side-band event) delivery (Kan Liang) - Rework Intel family name macro usage (this is partially x86 arch work) (Dave Hansen) - Refine and fix Intel LBR support (David Carrillo-Cisneros) - Add support for Intel 'TopDown' events (Andi Kleen) - Intel uncore PMU driver fixes and enhancements (Kan Liang) - ... other misc changes. Here's an incomplete list of the tooling enhancements (but there's much more, see the shortlog and the git log for details): - Support cross unwinding, i.e. collecting '--call-graph dwarf' perf.data files in one machine and then doing analysis in another machine of a different hardware architecture. This enables, for instance, to do: $ perf record -a --call-graph dwarf on a x86-32 or aarch64 system and then do 'perf report' on it on a x86_64 workstation (He Kuang) - Allow reading from a backward ring buffer (one setup via sys_perf_event_open() with perf_event_attr.write_backward = 1) (Wang Nan) - Finish merging initial SDT (Statically Defined Traces) support, see cset comments for details about how it all works (Masami Hiramatsu) - Support attaching eBPF programs to tracepoints (Wang Nan) - Add demangling of symbols in programs written in the Rust language (David Tolnay) - Add support for tracepoints in the python binding, including an example, that sets up and parses sched:sched_switch events, tools/perf/python/tracepoint.py (Jiri Olsa) - Introduce --stdio-color to set up the color output mode selection in 'annotate' and 'report', allowing emit color escape sequences when redirecting the output of these tools (Arnaldo Carvalho de Melo) - Add 'callindent' option to 'perf script -F', to indent the Intel PT call stack, making this output more ftrace-like (Adrian Hunter, Andi Kleen) - Allow dumping the object files generated by llvm when processing eBPF scriptlet events (Wang Nan) - Add stackcollapse.py script to help generating flame graphs (Paolo Bonzini) - Add --ldlat option to 'perf mem' to specify load latency for loads event (e.g. cpu/mem-loads/ ) (Jiri Olsa) - Tooling support for Intel TopDown counters, recently added to the kernel (Andi Kleen)" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (303 commits) perf tests: Add is_printable_array test perf tools: Make is_printable_array global perf script python: Fix string vs byte array resolving perf probe: Warn unmatched function filter correctly perf cpu_map: Add more helpers perf stat: Balance opening and reading events tools: Copy linux/{hash,poison}.h and check for drift perf tools: Remove include/linux/list.h from perf's MANIFEST tools: Copy the bitops files accessed from the kernel and check for drift Remove: kernel unistd*h files from perf's MANIFEST, not used perf tools: Remove tools/perf/util/include/linux/const.h perf tools: Remove tools/perf/util/include/asm/byteorder.h perf tools: Add missing linux/compiler.h include to perf-sys.h perf jit: Remove some no-op error handling perf jit: Add missing curly braces objtool: Initialize variable to silence old compiler objtool: Add -I$(srctree)/tools/arch/$(ARCH)/include/uapi perf record: Add --tail-synthesize option perf session: Don't warn about out of order event if write_backward is used perf tools: Enable overwrite settings ...
2016-07-23x86/insn: remove pcommitDan Williams
The pcommit instruction is being deprecated in favor of either ADR (asynchronous DRAM refresh: flush-on-power-fail) at the platform level, or posted-write-queue flush addresses as defined by the ACPI 6.x NFIT (NVDIMM Firmware Interface Table). Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Ingo Molnar <mingo@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-07-22tools build: Fix objtool build with ARCH=x86_64Josh Poimboeuf
The objtool build fails in a cross-compiled environment on a non-x86 host with "ARCH=x86_64": tools/objtool/objtool-in.o: In function `decode_instructions': tools/objtool/builtin-check.c:276: undefined reference to `arch_decode_instruction' We could override the ARCH environment variable and change it back to x86, similar to what the objtool Makefile was doing before; but it's tricky to override environment variables consistently. Instead, take a similar approach used by the Linux top-level Makefile and introduce a SRCARCH Makefile variable which evaluates to "x86" when ARCH is either "x86_64" or "x86". Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160722191920.ej62fnspnqurbaa7@treble Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-22objtool: Always use host headersArnaldo Carvalho de Melo
From a conversation with Josh: From http://lkml.kernel.org/r/20160722034118.guckaniobf3f7czc@treble : It needs to be compiled with the host (powerpc) compiler, but then it needs to disassemble target (x86) files. ---- So use HOSTARCH instead of ARCH. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20160722034118.guckaniobf3f7czc@treble Link: http://lkml.kernel.org/n/tip-le1m1yzxnfpt3msbblu40nm8@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-22objtool: Use tools/scripts/Makefile.arch to get ARCH and HOSTARCHArnaldo Carvalho de Melo
objtool's Makefile was setting up ARCH but fixing up just the x86_64 -> x86, using Makefile.arch will do the necessary fixups for all arches. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-hbq0bbh03u2b722vozcyql31@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-15objtool: Initialize variable to silence old compilerArnaldo Carvalho de Melo
gcc version 4.1.2 20080704 (Red Hat 4.1.2-55) barfs with: CC /tmp/build/objtool/builtin-check.o cc1: warnings being treated as errors builtin-check.c: In function 'cmd_check': builtin-check.c:667: warning: 'prev_rela' may be used uninitialized in this function mv: cannot stat `/tmp/build/objtool/.builtin-check.o.tmp': No such file or directory make[1]: *** [/tmp/build/objtool/builtin-check.o] Error 1 Init it to NULL to silence it. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-qolo31rl2ojlwj1lj9dhemyz@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-15objtool: Add -I$(srctree)/tools/arch/$(ARCH)/include/uapiArnaldo Carvalho de Melo
So that it can find asm/bitsperlong.h to get the __BITS_PER_LONG definition. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-pr3pvskh65pey4po7t122z4j@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-13objtool: Avoid checking code drift on busybox's diffArnaldo Carvalho de Melo
That doesn't have -I to match lines. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-1zqv1h6okt70e2huokkdtf1u@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-13objtool: Add fallback from ELF_C_READ_MMAP to ELF_C_READArnaldo Carvalho de Melo
Not all libelf implementations have this "Please, ELF_C_READ, but use mmap if possible" elf_begin() cmd, so provide a fallback to plain old ELF_C_READ. Case in point: Alpine Linux 3.4. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-1fctuknrawgoi5xqon4mu9dv@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-12tools lib subcmd: Use str_error_r()Arnaldo Carvalho de Melo
To make it portable to non-glibc systems, that follow the XSI variant instead of the GNU specific one that gets in place when _GNU_SOURCE is defined. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-bozcszy93tpgw9ad6qm3dhpx@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-12perf tools: Uninline scnprintf() and vscnprint()Arnaldo Carvalho de Melo
They were in tools/include/linux/kernel.h, requiring that it in turn included stdio.h, which is way too heavy. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-855h8olnkot9v0dajuee1lo3@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-10objtool: Fix STACK_FRAME_NON_STANDARD macro checking for function symbolsJosh Poimboeuf
Mathieu Desnoyers reported that the STACK_FRAME_NON_STANDARD macro wasn't working with the lttng_filter_interpret_bytecode() function in the lttng-modules code. Usually the relocation created by STACK_FRAME_NON_STANDARD creates a reference to a section symbol like this: Offset Type Value Addend Name 000000000000000000 X86_64_64 000000000000000000 +3136 .text But in this case it created a reference to a function symbol: Offset Type Value Addend Name 000000000000000000 X86_64_64 0x00000000000003a0 +0 lttng_filter_interpret_bytecode To be honest I have no idea what causes gcc to decide to do one over the other. But both are valid ELF, so add support for the function symbol. Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: lttng-dev@lists.lttng.org Link: http://lkml.kernel.org/r/9cee42843bc6d94e990a152e4e0319cfdf6756ef.1466023450.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-17objtool: Allow building with older libelfJan Beulich
The switch to elf_getshdr{num,strndx} post-dates the oldest tool chain the kernel is supposed to be able to build with, so try to cope with such an environment. Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: <stable@vger.kernel.org> # for v4.6 Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/732dae6872b7ff187d94f22bb699a12849d3fe04.1463430618.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-16objtool: Detect falling through to the next functionJosh Poimboeuf
There are several cases in compiled C code where a function may not return at the end, and may instead fall through to the next function. That may indicate a bug in the code, or a gcc bug, or even an objtool bug. But in each case, objtool reports an unhelpful warning, something like: drivers/scsi/qla2xxx/qla_attr.o: warning: objtool: qla2x00_get_fc_host_stats()+0x0: duplicate frame pointer save drivers/scsi/qla2xxx/qla_attr.o: warning: objtool: qla2x00_get_fc_host_stats()+0x0: frame pointer state mismatch Detect this situation and print a more useful error message: drivers/scsi/qla2xxx/qla_attr.o: warning: objtool: qla2x00_get_host_fabric_name() falls through to next function qla2x00_get_starget_node_name() Also add some information about this warning and its potential causes to the documentation. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> 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: Jiri Olsa <jolsa@redhat.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/caa4ec6c687931db805e692d4e4bf06cd87d33e6.1460729697.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-15objtool: Add workaround for GCC switch jump table bugJosh Poimboeuf
GCC has a rare quirk, currently only seen in three driver functions in the kernel, and only with certain obscure non-distro configs, which can cause objtool to produce "unreachable instruction" false positive warnings. As part of an optimization, GCC makes a copy of an existing switch jump table, modifies it, and then hard-codes the jump (albeit with an indirect jump) to use a single entry in the table. The rest of the jump table and some of its jump targets remain as dead code. In such a case we can just crudely ignore all unreachable instruction warnings for the entire object file. Ideally we would just ignore them for the function, but that would require redesigning the code quite a bit. And honestly that's just not worth doing: unreachable instruction warnings are of questionable value anyway, and this is a very rare issue. kbuild reports: https://lkml.kernel.org/r/201603231906.LWcVUpxm%25fengguang.wu@intel.com https://lkml.kernel.org/r/201603271114.K9i45biy%25fengguang.wu@intel.com https://lkml.kernel.org/r/201603291058.zuJ6ben1%25fengguang.wu@intel.com GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70604 Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.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/700fa029bbb0feff34f03ffc69d666a3c3b57a61.1460663532.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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