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* objtool: Introduce CFI hashPeter Zijlstra2022-07-251-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8b946cc38e063f0f7bb67789478c38f6d7d457c9 upstream. Andi reported that objtool on vmlinux.o consumes more memory than his system has, leading to horrific performance. This is in part because we keep a struct instruction for every instruction in the file in-memory. Shrink struct instruction by removing the CFI state (which includes full register state) from it and demand allocating it. Given most instructions don't actually change CFI state, there's lots of repetition there, so add a hash table to find previous CFI instances. Reduces memory consumption (and runtime) for processing an x86_64-allyesconfig: pre: 4:40.84 real, 143.99 user, 44.18 sys, 30624988 mem post: 2:14.61 real, 108.58 user, 25.04 sys, 16396184 mem Suggested-by: Andi Kleen <andi@firstfloor.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210624095147.756759107@infradead.org Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> [bwh: Backported to 5.10: - Don't use bswap_if_needed() since we don't have any of the other fixes for mixed-endian cross-compilation - Since we don't have "objtool: Rewrite hashtable sizing", make cfi_hash_alloc() set the number of bits similarly to elf_hash_bits() - objtool doesn't have any mcount handling - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* objtool: Create reloc sections implicitlyPeter Zijlstra2022-07-251-2/+0
| | | | | | | | | | | | | | | | commit d0c5c4cc73da0b05b0d9e5f833f2d859e1b45f8e upstream. Have elf_add_reloc() create the relocation section implicitly. Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/20210326151259.880174448@infradead.org [bwh: Backported to 5.10: drop changes in create_mcount_loc_sections()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* objtool: Add elf_create_reloc() helperPeter Zijlstra2022-07-251-24/+6
| | | | | | | | | | | | | | | | commit ef47cc01cb4abcd760d8ac66b9361d6ade4d0846 upstream. We have 4 instances of adding a relocation. Create a common helper to avoid growing even more. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/20210326151259.817438847@infradead.org [bwh: Backported to 5.10: drop changes in create_mcount_loc_sections()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* objtool: Rework the elf_rebuild_reloc_section() logicPeter Zijlstra2022-07-251-3/+0
| | | | | | | | | | | | | | | | | | | commit 3a647607b57ad8346e659ddd3b951ac292c83690 upstream. Instead of manually calling elf_rebuild_reloc_section() on sections we've called elf_add_reloc() on, have elf_write() DTRT. This makes it easier to add random relocations in places without carefully tracking when we're done and need to flush what section. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/20210326151259.754213408@infradead.org [bwh: Backported to 5.10: drop changes in create_mcount_loc_sections()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* objtool: Support stack layout changes in alternativesJosh Poimboeuf2022-07-251-8/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c9c324dc22aab1687da37001b321b6dfa93a0699 upstream. The ORC unwinder showed a warning [1] which revealed the stack layout didn't match what was expected. The problem was that paravirt patching had replaced "CALL *pv_ops.irq.save_fl" with "PUSHF;POP". That changed the stack layout between the PUSHF and the POP, so unwinding from an interrupt which occurred between those two instructions would fail. Part of the agreed upon solution was to rework the custom paravirt patching code to use alternatives instead, since objtool already knows how to read alternatives (and converging runtime patching infrastructure is always a good thing anyway). But the main problem still remains, which is that runtime patching can change the stack layout. Making stack layout changes in alternatives was disallowed with commit 7117f16bf460 ("objtool: Fix ORC vs alternatives"), but now that paravirt is going to be doing it, it needs to be supported. One way to do so would be to modify the ORC table when the code gets patched. But ORC is simple -- a good thing! -- and it's best to leave it alone. Instead, support stack layout changes by "flattening" all possible stack states (CFI) from parallel alternative code streams into a single set of linear states. The only necessary limitation is that CFI conflicts are disallowed at all possible instruction boundaries. For example, this scenario is allowed: Alt1 Alt2 Alt3 0x00 CALL *pv_ops.save_fl CALL xen_save_fl PUSHF 0x01 POP %RAX 0x02 NOP ... 0x05 NOP ... 0x07 <insn> The unwind information for offset-0x00 is identical for all 3 alternatives. Similarly offset-0x05 and higher also are identical (and the same as 0x00). However offset-0x01 has deviating CFI, but that is only relevant for Alt3, neither of the other alternative instruction streams will ever hit that offset. This scenario is NOT allowed: Alt1 Alt2 0x00 CALL *pv_ops.save_fl PUSHF 0x01 NOP6 ... 0x07 NOP POP %RAX The problem here is that offset-0x7, which is an instruction boundary in both possible instruction patch streams, has two conflicting stack layouts. [ The above examples were stolen from Peter Zijlstra. ] The new flattened CFI array is used both for the detection of conflicts (like the second example above) and the generation of linear ORC entries. BTW, another benefit of these changes is that, thanks to some related cleanups (new fake nops and alt_group struct) objtool can finally be rid of fake jumps, which were a constant source of headaches. [1] https://lkml.kernel.org/r/20201111170536.arx2zbn4ngvjoov7@treble Cc: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* objtool: Refactor ORC section generationJosh Poimboeuf2022-07-251-135/+137
| | | | | | | | | | | | commit ab4e0744e99b87e1a223e89fc3c9ae44f727c9a6 upstream. Decouple ORC entries from instructions. This simplifies the control/data flow, and is going to make it easier to support alternative instructions which change the stack layout. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* objtool: Fix seg fault with Clang non-section symbolsJosh Poimboeuf2021-02-171-24/+5
| | | | | | | | | | | | | | | | | | | | | | | | commit 44f6a7c0755d8dd453c70557e11687bb080a6f21 upstream. The Clang assembler likes to strip section symbols, which means objtool can't reference some text code by its section. This confuses objtool greatly, causing it to seg fault. The fix is similar to what was done before, for ORC reloc generation: e81e07244325 ("objtool: Support Clang non-section symbols in ORC generation") Factor out that code into a common helper and use it for static call reloc generation as well. Reported-by: Arnd Bergmann <arnd@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://github.com/ClangBuiltLinux/linux/issues/1207 Link: https://lkml.kernel.org/r/ba6b6c0f0dd5acbba66e403955a967d9fdd1726a.1607983452.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* objtool: Make unwind hint definitions available to other architecturesJulien Thierry2020-09-101-1/+4
| | | | | | | | | | | | | | | | | Unwind hints are useful to provide objtool with information about stack states in non-standard functions/code. While the type of information being provided might be very arch specific, the mechanism to provide the information can be useful for other architectures. Move the relevant unwint hint definitions for all architectures to see. [ jpoimboe: REGS_IRET -> REGS_PARTIAL ] Signed-off-by: Julien Thierry <jthierry@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
* objtool: Skip ORC entry creation for non-text sectionsJulien Thierry2020-09-011-0/+3
| | | | | | | | | | | | Orc generation is only done for text sections, but some instructions can be found in non-text sections (e.g. .discard.text sections). Skip setting their orc sections since their whole sections will be skipped for orc generation. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Julien Thierry <jthierry@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
* x86/static_call: Add inline static call implementation for x86-64Josh Poimboeuf2020-09-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | Add the inline static call implementation for x86-64. The generated code is identical to the out-of-line case, except we move the trampoline into it's own section. Objtool uses the trampoline naming convention to detect all the call sites. It then annotates those call sites in the .static_call_sites section. During boot (and module init), the call sites are patched to call directly into the destination function. The temporary trampoline is then no longer used. [peterz: merged trampolines, put trampoline in section] Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20200818135804.864271425@infradead.org
* Merge branch 'objtool/urgent' into objtool/corePeter Zijlstra2020-06-181-1/+1
|\ | | | | | | | | | | | | | | | | | | Conflicts: tools/objtool/elf.c tools/objtool/elf.h tools/objtool/orc_gen.c tools/objtool/check.c Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * objtool: Clean up elf_write() conditionPeter Zijlstra2020-06-181-1/+1
| | | | | | | | | | | | | | With there being multiple ways to change the ELF data, let's more concisely track modification. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
* | objtool: Add support for relocations without addendsMatt Helsley2020-06-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | Currently objtool only collects information about relocations with addends. In recordmcount, which we are about to merge into objtool, some supported architectures do not use rela relocations. Signed-off-by: Matt Helsley <mhelsley@vmware.com> Reviewed-by: Julien Thierry <jthierry@redhat.com> Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
* | objtool: Rename rela to relocMatt Helsley2020-06-011-23/+23
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before supporting additional relocation types rename the relevant types and functions from "rela" to "reloc". This work be done with the following regex: sed -e 's/struct rela/struct reloc/g' \ -e 's/\([_\*]\)rela\(s\{0,1\}\)/\1reloc\2/g' \ -e 's/tmprela\(s\{0,1\}\)/tmpreloc\1/g' \ -e 's/relasec/relocsec/g' \ -e 's/rela_list/reloc_list/g' \ -e 's/rela_hash/reloc_hash/g' \ -e 's/add_rela/add_reloc/g' \ -e 's/rela->/reloc->/g' \ -e '/rela[,\.]/{ s/\([^\.>]\)rela\([\.,]\)/\1reloc\2/g ; }' \ -e 's/rela =/reloc =/g' \ -e 's/relas =/relocs =/g' \ -e 's/relas\[/relocs[/g' \ -e 's/relaname =/relocname =/g' \ -e 's/= rela\;/= reloc\;/g' \ -e 's/= relas\;/= relocs\;/g' \ -e 's/= relaname\;/= relocname\;/g' \ -e 's/, rela)/, reloc)/g' \ -e 's/\([ @]\)rela\([ "]\)/\1reloc\2/g' \ -e 's/ rela$/ reloc/g' \ -e 's/, relaname/, relocname/g' \ -e 's/sec->rela/sec->reloc/g' \ -e 's/(\(!\{0,1\}\)rela/(\1reloc/g' \ -i \ arch.h \ arch/x86/decode.c \ check.c \ check.h \ elf.c \ elf.h \ orc_gen.c \ special.c Notable exceptions which complicate the regex include gelf_* library calls and standard/expected section names which still use "rela" because they encode the type of relocation expected. Also, keep "rela" in the struct because it encodes a specific type of relocation we currently expect. It will eventually turn into a member of an anonymous union when a susequent patch adds implicit addend, or "rel", relocation support. Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
* objtool: Enable compilation of objtool for all architecturesMatt Helsley2020-05-201-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Objtool currently only compiles for x86 architectures. This is fine as it presently does not support tooling for other architectures. However, we would like to be able to convert other kernel tools to run as objtool sub commands because they too process ELF object files. This will allow us to convert tools such as recordmcount to use objtool's ELF code. Since much of recordmcount's ELF code is copy-paste code to/from a variety of other kernel tools (look at modpost for example) this means that if we can convert recordmcount we can convert more. We define weak definitions for subcommand entry functions and other weak definitions for shared functions critical to building existing subcommands. These return 127 when the command is missing which signify tools that do not exist on all architectures. In this case the "check" and "orc" tools do not exist on all architectures so we only add them for x86. Future changes adding support for "check", to arm64 for example, can then modify the SUBCMD_CHECK variable when building for arm64. Objtool is not currently wired in to KConfig to be built for other architectures because it's not needed for those architectures and there are no commands it supports other than those for x86. As more command support is enabled on various architectures the necessary KConfig changes can be made (e.g. adding "STACK_VALIDATION") to trigger building objtool. [ jpoimboe: remove aliases, add __weak macro, add error messages ] Cc: Julien Thierry <jthierry@redhat.com> Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
* objtool: Optimize !vmlinux.o againPeter Zijlstra2020-04-221-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | When doing kbuild tests to see if the objtool changes affected those I found that there was a measurable regression: pre post real 1m13.594 1m16.488s user 34m58.246s 35m23.947s sys 4m0.393s 4m27.312s Perf showed that for small files the increased hash-table sizes were a measurable difference. Since we already have -l "vmlinux" to distinguish between the modes, make it also use a smaller portion of the hash-tables. This flips it into a small win: real 1m14.143s user 34m49.292s sys 3m44.746s Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200416115119.167588731@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix !CFI insn_state propagationPeter Zijlstra2020-04-221-4/+4
| | | | | | | | | | | | | | | | | Objtool keeps per instruction CFI state in struct insn_state and will save/restore this where required. However, insn_state has grown some !CFI state, and this must not be saved/restored (that would loose/destroy state). Fix this by moving the CFI specific parts of insn_state into struct cfi_state. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200416115119.045821071@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Support Clang non-section symbols in ORC generationJosh Poimboeuf2020-04-141-7/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When compiling the kernel with AS=clang, objtool produces a lot of warnings: warning: objtool: missing symbol for section .text warning: objtool: missing symbol for section .init.text warning: objtool: missing symbol for section .ref.text It then fails to generate the ORC table. The problem is that objtool assumes text section symbols always exist. But the Clang assembler is aggressive about removing them. When generating relocations for the ORC table, objtool always tries to reference instructions by their section symbol offset. If the section symbol doesn't exist, it bails. Do a fallback: when a section symbol isn't available, reference a function symbol instead. Reported-by: Dmitry Golovin <dima@golovin.in> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://github.com/ClangBuiltLinux/linux/issues/669 Link: https://lkml.kernel.org/r/9a9cae7fcf628843aabe5a086b1a3c5bf50f42e8.1585761021.git.jpoimboe@redhat.com
* objtool: Optimize read_sections()Peter Zijlstra2020-03-251-4/+5
| | | | | | | | | | | | | | | | | Perf showed that __hash_init() is a significant portion of read_sections(), so instead of doing a per section rela_hash, use an elf-wide rela_hash. Statistics show us there are about 1.1 million relas, so size it accordingly. This reduces the objtool on vmlinux.o runtime to a third, from 15 to 5 seconds. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.739153726@infradead.org
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13Thomas Gleixner2019-05-211-13/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details [based] [from] [clk] [highbank] [c] you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 355 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190519154041.837383322@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/unwind/orc: Detect the end of the stackJosh Poimboeuf2018-06-211-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | The existing UNWIND_HINT_EMPTY annotations happen to be good indicators of where entry code calls into C code for the first time. So also use them to mark the end of the stack for the ORC unwinder. Use that information to set unwind->error if the ORC unwinder doesn't unwind all the way to the end. This will be needed for enabling HAVE_RELIABLE_STACKTRACE for the ORC unwinder so we can use it with the livepatch consistency model. Thanks to Jiri Slaby for teaching the ORCs about the unwind hints. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> 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: https://lkml.kernel.org/lkml/20180518064713.26440-5-jslaby@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Warn on stripped section symbolJosh Poimboeuf2018-01-301-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | With the following fix: 2a0098d70640 ("objtool: Fix seg fault with gold linker") ... a seg fault was avoided, but the original seg fault condition in objtool wasn't fixed. Replace the seg fault with an error message. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.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/dc4585a70d6b975c99fc51d1957ccdde7bd52f3a.1517284349.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix seg fault with clang-compiled objectsSimon Ser2017-12-301-0/+2
| | | | | | | | | | | | | | Fix a seg fault which happens when an input file provided to 'objtool orc generate' doesn't have a '.shstrtab' section (for instance, object files produced by clang don't have this section). Signed-off-by: Simon Ser <contact@emersion.fr> 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/c0f2231683e9bed40fac1f13ce2c33b8389854bc.1514666459.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Add ORC unwind table generationJosh Poimboeuf2017-07-181-0/+214
Now that objtool knows the states of all registers on the stack for each instruction, it's straightforward to generate debuginfo for an unwinder to use. Instead of generating DWARF, generate a new format called ORC, which is more suitable for an in-kernel unwinder. See Documentation/x86/orc-unwinder.txt for a more detailed description of this new debuginfo format and why it's preferable to DWARF. 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: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/c9b9f01ba6c5ed2bdc9bb0957b78167fdbf9632e.1499786555.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 04:32:05 +0000