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2024-03-27objtool: Fix UNWIND_HINT_{SAVE,RESTORE} across basic blocksJosh Poimboeuf1-0/+12
[ Upstream commit 10b4c4bce3f5541f54bcc2039720b11d2bc96d79 ] If SAVE and RESTORE unwind hints are in different basic blocks, and objtool sees the RESTORE before the SAVE, it errors out with: vmlinux.o: warning: objtool: vmw_port_hb_in+0x242: objtool isn't smart enough to handle this CFI save/restore combo In such a case, defer following the RESTORE block until the straight-line path gets followed later. Fixes: 8faea26e6111 ("objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402240702.zJFNmahW-lkp@intel.com/ Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lore.kernel.org/r/20240227073527.avcm5naavbv3cj5s@treble Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-20cred: get rid of CONFIG_DEBUG_CREDENTIALSJens Axboe1-1/+0
commit ae1914174a63a558113e80d24ccac2773f9f7b2b upstream. This code is rarely (never?) enabled by distros, and it hasn't caught anything in decades. Let's kill off this legacy debug code. Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-20objtool: Propagate early errorsAaron Plattner1-3/+1
[ Upstream commit e959c279d391c10b35ce300fb4b0fe3b98e86bd2 ] If objtool runs into a problem that causes it to exit early, the overall tool still returns a status code of 0, which causes the build to continue as if nothing went wrong. Note this only affects early errors, as later errors are still ignored by check(). Fixes: b51277eb9775 ("objtool: Ditch subcommands") Signed-off-by: Aaron Plattner <aplattner@nvidia.com> Link: https://lore.kernel.org/r/cb6a28832d24b2ebfafd26da9abb95f874c83045.1696355111.git.aplattner@nvidia.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-12objtool: Fix _THIS_IP_ detection for cold functionsJosh Poimboeuf1-1/+2
Cold functions and their non-cold counterparts can use _THIS_IP_ to reference each other. Don't warn about !ENDBR in that case. Note that for GCC this is currently irrelevant in light of the following commit c27cd083cfb9 ("Compiler attributes: GCC cold function alignment workarounds") which disabled cold functions in the kernel. However this may still be possible with Clang. Fixes several warnings like the following: drivers/scsi/bnx2i/bnx2i.prelink.o: warning: objtool: bnx2i_hw_ep_disconnect+0x19d: relocation to !ENDBR: bnx2i_hw_ep_disconnect.cold+0x0 drivers/net/ipvlan/ipvlan.prelink.o: warning: objtool: ipvlan_addr4_event.cold+0x28: relocation to !ENDBR: ipvlan_addr4_event+0xda drivers/net/ipvlan/ipvlan.prelink.o: warning: objtool: ipvlan_addr6_event.cold+0x26: relocation to !ENDBR: ipvlan_addr6_event+0xb7 drivers/net/ethernet/broadcom/tg3.prelink.o: warning: objtool: tg3_set_ringparam.cold+0x17: relocation to !ENDBR: tg3_set_ringparam+0x115 drivers/net/ethernet/broadcom/tg3.prelink.o: warning: objtool: tg3_self_test.cold+0x17: relocation to !ENDBR: tg3_self_test+0x2e1 drivers/target/iscsi/cxgbit/cxgbit.prelink.o: warning: objtool: __cxgbit_free_conn.cold+0x24: relocation to !ENDBR: __cxgbit_free_conn+0xfb net/can/can.prelink.o: warning: objtool: can_rx_unregister.cold+0x2c: relocation to !ENDBR: can_rx_unregister+0x11b drivers/net/ethernet/qlogic/qed/qed.prelink.o: warning: objtool: qed_spq_post+0xc0: relocation to !ENDBR: qed_spq_post.cold+0x9a drivers/net/ethernet/qlogic/qed/qed.prelink.o: warning: objtool: qed_iwarp_ll2_comp_syn_pkt.cold+0x12f: relocation to !ENDBR: qed_iwarp_ll2_comp_syn_pkt+0x34b net/tipc/tipc.prelink.o: warning: objtool: tipc_nametbl_publish.cold+0x21: relocation to !ENDBR: tipc_nametbl_publish+0xa6 Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/d8f1ab6a23a6105bc023c132b105f245c7976be6.1694476559.git.jpoimboe@kernel.org
2023-08-17objtool/x86: Fixup frame-pointer vs rethunkPeter Zijlstra1-6/+11
For stack-validation of a frame-pointer build, objtool validates that every CALL instruction is preceded by a frame-setup. The new SRSO return thunks violate this with their RSB stuffing trickery. Extend the __fentry__ exception to also cover the embedded_insn case used for this. This cures: vmlinux.o: warning: objtool: srso_untrain_ret+0xd: call without frame pointer save/setup Fixes: 4ae68b26c3ab ("objtool/x86: Fix SRSO mess") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lore.kernel.org/r/20230816115921.GH980931@hirez.programming.kicks-ass.net
2023-08-16x86/cpu: Rename original retbleed methodsPeter Zijlstra2-2/+2
Rename the original retbleed return thunk and untrain_ret to retbleed_return_thunk() and retbleed_untrain_ret(). No functional changes. Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230814121148.909378169@infradead.org
2023-08-16x86/cpu: Clean up SRSO return thunk messPeter Zijlstra1-1/+1
Use the existing configurable return thunk. There is absolute no justification for having created this __x86_return_thunk alternative. To clarify, the whole thing looks like: Zen3/4 does: srso_alias_untrain_ret: nop2 lfence jmp srso_alias_return_thunk int3 srso_alias_safe_ret: // aliasses srso_alias_untrain_ret just so add $8, %rsp ret int3 srso_alias_return_thunk: call srso_alias_safe_ret ud2 While Zen1/2 does: srso_untrain_ret: movabs $foo, %rax lfence call srso_safe_ret (jmp srso_return_thunk ?) int3 srso_safe_ret: // embedded in movabs instruction add $8,%rsp ret int3 srso_return_thunk: call srso_safe_ret ud2 While retbleed does: zen_untrain_ret: test $0xcc, %bl lfence jmp zen_return_thunk int3 zen_return_thunk: // embedded in the test instruction ret int3 Where Zen1/2 flush the BTB entry using the instruction decoder trick (test,movabs) Zen3/4 use BTB aliasing. SRSO adds a return sequence (srso_safe_ret()) which forces the function return instruction to speculate into a trap (UD2). This RET will then mispredict and execution will continue at the return site read from the top of the stack. Pick one of three options at boot (evey function can only ever return once). [ bp: Fixup commit message uarch details and add them in a comment in the code too. Add a comment about the srso_select_mitigation() dependency on retbleed_select_mitigation(). Add moar ifdeffery for 32-bit builds. Add a dummy srso_untrain_ret_alias() definition for 32-bit alternatives needing the symbol. ] Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230814121148.842775684@infradead.org
2023-08-16objtool/x86: Fix SRSO messPeter Zijlstra4-6/+31
Objtool --rethunk does two things: - it collects all (tail) call's of __x86_return_thunk and places them into .return_sites. These are typically compiler generated, but RET also emits this same. - it fudges the validation of the __x86_return_thunk symbol; because this symbol is inside another instruction, it can't actually find the instruction pointed to by the symbol offset and gets upset. Because these two things pertained to the same symbol, there was no pressing need to separate these two separate things. However, alas, along comes SRSO and more crazy things to deal with appeared. The SRSO patch itself added the following symbol names to identify as rethunk: 'srso_untrain_ret', 'srso_safe_ret' and '__ret' Where '__ret' is the old retbleed return thunk, 'srso_safe_ret' is a new similarly embedded return thunk, and 'srso_untrain_ret' is completely unrelated to anything the above does (and was only included because of that INT3 vs UD2 issue fixed previous). Clear things up by adding a second category for the embedded instruction thing. Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230814121148.704502245@infradead.org
2023-08-14x86/retpoline,kprobes: Fix position of thunk sections with CONFIG_LTO_CLANGPetr Pavlu1-1/+1
The linker script arch/x86/kernel/vmlinux.lds.S matches the thunk sections ".text.__x86.*" from arch/x86/lib/retpoline.S as follows: .text { [...] TEXT_TEXT [...] __indirect_thunk_start = .; *(.text.__x86.*) __indirect_thunk_end = .; [...] } Macro TEXT_TEXT references TEXT_MAIN which normally expands to only ".text". However, with CONFIG_LTO_CLANG, TEXT_MAIN becomes ".text .text.[0-9a-zA-Z_]*" which wrongly matches also the thunk sections. The output layout is then different than expected. For instance, the currently defined range [__indirect_thunk_start, __indirect_thunk_end] becomes empty. Prevent the problem by using ".." as the first separator, for example, ".text..__x86.indirect_thunk". This pattern is utilized by other explicit section names which start with one of the standard prefixes, such as ".text" or ".data", and that need to be individually selected in the linker script. [ nathan: Fix conflicts with SRSO and fold in fix issue brought up by Andrew Cooper in post-review: https://lore.kernel.org/20230803230323.1478869-1-andrew.cooper3@citrix.com ] Fixes: dc5723b02e52 ("kbuild: add support for Clang LTO") Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230711091952.27944-2-petr.pavlu@suse.com
2023-07-27x86/srso: Add a Speculative RAS Overflow mitigationBorislav Petkov (AMD)1-1/+4
Add a mitigation for the speculative return address stack overflow vulnerability found on AMD processors. The mitigation works by ensuring all RET instructions speculate to a controlled location, similar to how speculation is controlled in the retpoline sequence. To accomplish this, the __x86_return_thunk forces the CPU to mispredict every function return using a 'safe return' sequence. To ensure the safety of this mitigation, the kernel must ensure that the safe return sequence is itself free from attacker interference. In Zen3 and Zen4, this is accomplished by creating a BTB alias between the untraining function srso_untrain_ret_alias() and the safe return function srso_safe_ret_alias() which results in evicting a potentially poisoned BTB entry and using that safe one for all function returns. In older Zen1 and Zen2, this is accomplished using a reinterpretation technique similar to Retbleed one: srso_untrain_ret() and srso_safe_ret(). Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2023-07-10objtool: initialize all of struct elfMichal Kubecek1-1/+1
Function elf_open_read() only zero initializes the initial part of allocated struct elf; num_relocs member was recently added outside the zeroed part so that it was left uninitialized, resulting in build failures on some systems. The partial initialization is a relic of times when struct elf had large hash tables embedded. This is no longer the case so remove the trap and initialize the whole structure instead. Fixes: eb0481bbc4ce ("objtool: Fix reloc_hash size") Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lore.kernel.org/r/20230629102051.42E8360467@lion.mk-sys.cz
2023-06-30objtool: Remove btrfs_assertfail() from the noreturn exceptions listIngo Molnar1-1/+0
The objtool merge in commit 6f612579be9d ("Merge tag 'objtool-core ...") generated a semantic conflict that was not resolved. The btrfs_assertfail() entry was removed from the noreturn list in commit b831306b3b7d ("btrfs: print assertion failure report and stack trace from the same line") because btrfs_assertfail() was changed from a noreturn function into a macro. The noreturn list was then moved from check.c to noreturns.h in commit 6245ce4ab670 ("objtool: Move noreturn function list to separate file"), and should be removed from that post-merge as well. Do it explicitly. Cc: David Sterba <dsterba@suse.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-28Merge tag 'objtool-core-2023-06-27' of ↵Linus Torvalds15-695/+908
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molar: "Build footprint & performance improvements: - Reduce memory usage with CONFIG_DEBUG_INFO=y In the worst case of an allyesconfig+CONFIG_DEBUG_INFO=y kernel, DWARF creates almost 200 million relocations, ballooning objtool's peak heap usage to 53GB. These patches reduce that to 25GB. On a distro-type kernel with kernel IBT enabled, they reduce objtool's peak heap usage from 4.2GB to 2.8GB. These changes also improve the runtime significantly. Debuggability improvements: - Add the unwind_debug command-line option, for more extend unwinding debugging output - Limit unreachable warnings to once per function - Add verbose option for disassembling affected functions - Include backtrace in verbose mode - Detect missing __noreturn annotations - Ignore exc_double_fault() __noreturn warnings - Remove superfluous global_noreturns entries - Move noreturn function list to separate file - Add __kunit_abort() to noreturns Unwinder improvements: - Allow stack operations in UNWIND_HINT_UNDEFINED regions - drm/vmwgfx: Add unwind hints around RBP clobber Cleanups: - Move the x86 entry thunk restore code into thunk functions - x86/unwind/orc: Use swap() instead of open coding it - Remove unnecessary/unused variables Fixes for modern stack canary handling" * tag 'objtool-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits) x86/orc: Make the is_callthunk() definition depend on CONFIG_BPF_JIT=y objtool: Skip reading DWARF section data objtool: Free insns when done objtool: Get rid of reloc->rel[a] objtool: Shrink elf hash nodes objtool: Shrink reloc->sym_reloc_entry objtool: Get rid of reloc->jump_table_start objtool: Get rid of reloc->addend objtool: Get rid of reloc->type objtool: Get rid of reloc->offset objtool: Get rid of reloc->idx objtool: Get rid of reloc->list objtool: Allocate relocs in advance for new rela sections objtool: Add for_each_reloc() objtool: Don't free memory in elf_close() objtool: Keep GElf_Rel[a] structs synced objtool: Add elf_create_section_pair() objtool: Add mark_sec_changed() objtool: Fix reloc_hash size objtool: Consolidate rel/rela handling ...
2023-06-27Merge tag 'linux-kselftest-kunit-6.5-rc1' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull KUnit updates from Shuah Khan: - kunit_add_action() API to defer a call until test exit - Update document to add kunit_add_action() usage notes - Changes to always run cleanup from a test kthread - Documentation updates to clarify cleanup usage (assertions should not be used in cleanup) - Documentation update to clearly indicate that exit functions should run even if init fails - Several fixes and enhancements to existing tests * tag 'linux-kselftest-kunit-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: MAINTAINERS: Add source tree entry for kunit Documentation: kunit: Rename references to kunit_abort() kunit: Move kunit_abort() call out of kunit_do_failed_assertion() kunit: Fix obsolete name in documentation headers (func->action) Documentation: Kunit: add MODULE_LICENSE to sample code kunit: Update kunit_print_ok_not_ok function kunit: Fix reporting of the skipped parameterized tests kunit/test: Add example test showing parameterized testing Documentation: kunit: Add usage notes for kunit_add_action() kunit: kmalloc_array: Use kunit_add_action() kunit: executor_test: Use kunit_add_action() kunit: Add kunit_add_action() to defer a call until test exit kunit: example: Provide example exit functions Documentation: kunit: Warn that exit functions run even if init fails Documentation: kunit: Note that assertions should not be used in cleanup kunit: Always run cleanup from a test kthread Documentation: kunit: Modular tests should not depend on KUNIT=y kunit: tool: undo type subscripts for subprocess.Popen
2023-06-27Merge tag 'x86_alternatives_for_v6.5' of ↵Linus Torvalds1-7/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 instruction alternatives updates from Borislav Petkov: - Up until now the Fast Short Rep Mov optimizations implied the presence of the ERMS CPUID flag. AMD decoupled them with a BIOS setting so decouple that dependency in the kernel code too - Teach the alternatives machinery to handle relocations - Make debug_alternative accept flags in order to see only that set of patching done one is interested in - Other fixes, cleanups and optimizations to the patching code * tag 'x86_alternatives_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/alternative: PAUSE is not a NOP x86/alternatives: Add cond_resched() to text_poke_bp_batch() x86/nospec: Shorten RESET_CALL_DEPTH x86/alternatives: Add longer 64-bit NOPs x86/alternatives: Fix section mismatch warnings x86/alternative: Optimize returns patching x86/alternative: Complicate optimize_nops() some more x86/alternative: Rewrite optimize_nops() some x86/lib/memmove: Decouple ERMS from FSRM x86/alternative: Support relocations in alternatives x86/alternative: Make debug-alternative selective
2023-06-19btrfs: print assertion failure report and stack trace from the same lineDavid Sterba1-1/+0
Assertions reports are split into two parts, the exact file and location of the condition and then the stack trace printed from btrfs_assertfail(). This means all the stack traces report the same line and this is what's typically reported by various tools, making it harder to distinguish the reports. [403.2467] assertion failed: refcount_read(&block_group->refs) == 1, in fs/btrfs/block-group.c:4259 [403.2479] ------------[ cut here ]------------ [403.2484] kernel BUG at fs/btrfs/messages.c:259! [403.2488] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [403.2493] CPU: 2 PID: 23202 Comm: umount Not tainted 6.2.0-rc4-default+ #67 [403.2499] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552-rebuilt.opensuse.org 04/01/2014 [403.2509] RIP: 0010:btrfs_assertfail+0x19/0x1b [btrfs] ... [403.2595] Call Trace: [403.2598] <TASK> [403.2601] btrfs_free_block_groups.cold+0x52/0xae [btrfs] [403.2608] close_ctree+0x6c2/0x761 [btrfs] [403.2613] ? __wait_for_common+0x2b8/0x360 [403.2618] ? btrfs_cleanup_one_transaction.cold+0x7a/0x7a [btrfs] [403.2626] ? mark_held_locks+0x6b/0x90 [403.2630] ? lockdep_hardirqs_on_prepare+0x13d/0x200 [403.2636] ? __call_rcu_common.constprop.0+0x1ea/0x3d0 [403.2642] ? trace_hardirqs_on+0x2d/0x110 [403.2646] ? __call_rcu_common.constprop.0+0x1ea/0x3d0 [403.2652] generic_shutdown_super+0xb0/0x1c0 [403.2657] kill_anon_super+0x1e/0x40 [403.2662] btrfs_kill_super+0x25/0x30 [btrfs] [403.2668] deactivate_locked_super+0x4c/0xc0 By making btrfs_assertfail a macro we'll get the same line number for the BUG output: [63.5736] assertion failed: 0, in fs/btrfs/super.c:1572 [63.5758] ------------[ cut here ]------------ [63.5782] kernel BUG at fs/btrfs/super.c:1572! [63.5807] invalid opcode: 0000 [#2] PREEMPT SMP KASAN [63.5831] CPU: 0 PID: 859 Comm: mount Tainted: G D 6.3.0-rc7-default+ #2062 [63.5868] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014 [63.5905] RIP: 0010:btrfs_mount+0x24/0x30 [btrfs] [63.5964] RSP: 0018:ffff88800e69fcd8 EFLAGS: 00010246 [63.5982] RAX: 000000000000002d RBX: ffff888008fc1400 RCX: 0000000000000000 [63.6004] RDX: 0000000000000000 RSI: ffffffffb90fd868 RDI: ffffffffbcc3ff20 [63.6026] RBP: ffffffffc081b200 R08: 0000000000000001 R09: ffff88800e69fa27 [63.6046] R10: ffffed1001cd3f44 R11: 0000000000000001 R12: ffff888005a3c370 [63.6062] R13: ffffffffc058e830 R14: 0000000000000000 R15: 00000000ffffffff [63.6081] FS: 00007f7b3561f800(0000) GS:ffff88806c600000(0000) knlGS:0000000000000000 [63.6105] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [63.6120] CR2: 00007fff83726e10 CR3: 0000000002a9e000 CR4: 00000000000006b0 [63.6137] Call Trace: [63.6143] <TASK> [63.6148] legacy_get_tree+0x80/0xd0 [63.6158] vfs_get_tree+0x43/0x120 [63.6166] do_new_mount+0x1f3/0x3d0 [63.6176] ? do_add_mount+0x140/0x140 [63.6187] ? cap_capable+0xa4/0xe0 [63.6197] path_mount+0x223/0xc10 This comes at a cost of bloating the final btrfs.ko module due all the inlining, as long as assertions are compiled in. This is a must for debugging builds but this is often enabled on release builds too. Release build: text data bss dec hex filename 1251676 20317 16088 1288081 13a791 pre/btrfs.ko 1260612 29473 16088 1306173 13ee3d post/btrfs.ko DELTA: +8936 CC: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-07objtool: Skip reading DWARF section dataJosh Poimboeuf1-1/+6
Objtool doesn't use DWARF at all, and the DWARF sections' data take up a lot of memory. Skip reading them. Note this only skips the DWARF base sections, not the rela sections. The relas are needed because their symbol references may need to be reindexed if any local symbols get added by elf_create_symbol(). Also note the DWARF data will eventually be read by libelf anyway, when writing the object file. But that's fine, the goal here is to reduce *peak* memory usage, and the previous patch (which freed insn memory) gave some breathing room. So the allocation gets shifted to a later time, resulting in lower peak memory usage. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 29.93G - After: peak heap memory consumption: 25.47G Link: https://lore.kernel.org/r/52a9698835861dd35f2ec35c49f96d0bb39fb177.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Free insns when doneJosh Poimboeuf1-0/+30
Free the decoded instructions as they're no longer needed after this point. This frees up a big chunk of heap, which will come handy when skipping the reading of DWARF section data. Link: https://lore.kernel.org/r/4d4bca1a0f869de020dac80d91f9acbf6df77eab.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Get rid of reloc->rel[a]Josh Poimboeuf3-78/+96
Get the relocation entry info from the underlying rsec->data. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 35.12G - After: peak heap memory consumption: 29.93G Link: https://lore.kernel.org/r/2be32323de6d8cc73179ee0ff14b71f4e7cefaa0.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Shrink elf hash nodesJosh Poimboeuf2-18/+58
Instead of using hlist for the 'struct elf' hashes, use a custom single-linked list scheme. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 36.89G - After: peak heap memory consumption: 35.12G Link: https://lore.kernel.org/r/6e8cd305ed22e743c30d6e72cfdc1be20fb94cd4.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Shrink reloc->sym_reloc_entryJosh Poimboeuf2-6/+7
Convert it to a singly-linked list. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 38.64G - After: peak heap memory consumption: 36.89G Link: https://lore.kernel.org/r/a51f0a6f9bbf2494d5a3a449807307e78a940988.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Get rid of reloc->jump_table_startJosh Poimboeuf2-13/+23
Rework the jump table logic slightly so 'jump_table_start' is no longer needed. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 40.37G - After: peak heap memory consumption: 38.64G Link: https://lore.kernel.org/r/e1602ed8a6171ada3cfac0bd8449892ec82bd188.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Get rid of reloc->addendJosh Poimboeuf6-42/+53
Get the addend from the embedded GElf_Rel[a] struct. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 42.10G - After: peak heap memory consumption: 40.37G Link: https://lore.kernel.org/r/ad2354f95d9ddd86094e3f7687acfa0750657784.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Get rid of reloc->typeJosh Poimboeuf5-13/+21
Get the type from the embedded GElf_Rel[a] struct. Link: https://lore.kernel.org/r/d1c1f8da31e4f052a2478aea585fcf355cacc53a.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Get rid of reloc->offsetJosh Poimboeuf3-14/+18
Get the offset from the embedded GElf_Rel[a] struct. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 43.83G - After: peak heap memory consumption: 42.10G Link: https://lore.kernel.org/r/2b9ec01178baa346a99522710bf2e82159412e3a.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Get rid of reloc->idxJosh Poimboeuf2-7/+9
Use the array offset to calculate the reloc index. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 45.56G - After: peak heap memory consumption: 43.83G Link: https://lore.kernel.org/r/7351d2ebad0519027db14a32f6204af84952574a.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Get rid of reloc->listJosh Poimboeuf2-24/+26
Now that all relocs are allocated in an array, the linked list is no longer needed. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 49.02G - After: peak heap memory consumption: 45.56G Link: https://lore.kernel.org/r/71e7a2c017dbc46bb497857ec97d67214f832d10.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Allocate relocs in advance for new rela sectionsJosh Poimboeuf1-5/+13
Similar to read_relocs(), allocate the reloc structs all together in an array rather than allocating them one at a time. Link: https://lore.kernel.org/r/5332d845c5a2d6c2d052075b381bfba8bcb67ed5.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Add for_each_reloc()Josh Poimboeuf2-12/+18
Link: https://lore.kernel.org/r/dbfcb1037d8b958e52d097b67829c4c6811c24bb.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Don't free memory in elf_close()Josh Poimboeuf1-20/+4
It's not necessary, objtool's about to exit anyway. Link: https://lore.kernel.org/r/74bdb3058b8f029db8d5b3b5175f2a200804196d.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Keep GElf_Rel[a] structs syncedJosh Poimboeuf1-41/+14
Keep the GElf_Rela structs synced with their 'struct reloc' counterparts instead of having to go back and "rebuild" them later. Link: https://lore.kernel.org/r/156d8a3e528a11e5c8577cf552890ed1f2b9567b.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Add elf_create_section_pair()Josh Poimboeuf6-157/+184
When creating an annotation section, allocate the reloc section data at the beginning. This simplifies the data model a bit and also saves memory due to the removal of malloc() in elf_rebuild_reloc_section(). With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 53.49G - After: peak heap memory consumption: 49.02G Link: https://lore.kernel.org/r/048e908f3ede9b66c15e44672b6dda992b1dae3e.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Add mark_sec_changed()Josh Poimboeuf2-16/+29
Ensure elf->changed always gets set when sec->changed gets set. Link: https://lore.kernel.org/r/9a810a8d2e28af6ba07325362d0eb4703bb09d3a.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Fix reloc_hash sizeJosh Poimboeuf2-10/+14
With CONFIG_DEBUG_INFO, DWARF creates a lot of relocations and reloc_hash is woefully undersized, which can affect performance significantly. Fix that. Link: https://lore.kernel.org/r/38ef60dc8043270bf3b9dfd139ae2a30ca3f75cc.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Consolidate rel/rela handlingJosh Poimboeuf3-159/+68
The GElf_Rel[a] structs have more similarities than differences. It's safe to hard-code the assumptions about their shared fields as they will never change. Consolidate their handling where possible, getting rid of duplicated code. Also, at least for now we only ever create rela sections, so simplify the relocation creation code to be rela-only. Link: https://lore.kernel.org/r/dcabf6df400ca500ea929f1e4284f5e5ec0b27c8.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Improve reloc namingJosh Poimboeuf3-149/+151
- The term "reloc" is overloaded to mean both "an instance of struct reloc" and "a reloc section". Change the latter to "rsec". - For variable names, use "sec" for regular sections and "rsec" for rela sections to prevent them getting mixed up. - For struct reloc variables, use "reloc" instead of "rel" everywhere for consistency. Link: https://lore.kernel.org/r/8b790e403df46f445c21003e7893b8f53b99a6f3.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Remove flags argument from elf_create_section()Josh Poimboeuf4-15/+18
Simplify the elf_create_section() interface a bit by removing the flags argument. Most callers don't care about changing the section header flags. If needed, they can be modified afterwards, just like any other section header field. Link: https://lore.kernel.org/r/515235d9cf62637a14bee37bfa9169ef20065471.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Tidy elf.hJosh Poimboeuf1-49/+47
Reorganize elf.h a bit: - Move the prototypes higher up so they can be used by the inline functions. - Move hash-related code to the bottom. - Remove the unused ELF_HASH_BITS macro. No functional changes. Link: https://lore.kernel.org/r/b1490ed85951868219a6ece177a7cd30a6454d66.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07objtool: Allow stack operations in UNWIND_HINT_UNDEFINED regionsJosh Poimboeuf2-0/+13
If the code specified UNWIND_HINT_UNDEFINED, skip the "undefined stack state" warning due to a stack operation. Just ignore the stack op and continue to propagate the undefined state. Link: https://lore.kernel.org/r/820c5b433f17c84e8761fb7465a8d319d706b1cf.1685981486.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07tools: Remove unnecessary variablesLu Hongfei1-4/+3
There are several places where warnings variables are not needed, remove them and directly return 0. Signed-off-by: Lu Hongfei <luhongfei@vivo.com> Link: https://lore.kernel.org/r/20230530075649.21661-1-luhongfei@vivo.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-02objtool: Add __kunit_abort() to noreturnsJosh Poimboeuf1-0/+1
Fixes a bunch of warnings like: drivers/input/tests/input_test.o: warning: objtool: input_test_init+0x1cb: stack state mismatch: cfa1=4+64 cfa2=4+56 lib/kunit/kunit-test.o: warning: objtool: kunit_log_newline_test+0xfb: return with modified stack frame ... Fixes: 260755184cbd ("kunit: Move kunit_abort() call out of kunit_do_failed_assertion()") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230602175453.swsn3ehyochtwkhy@treble
2023-05-16objtool: Move noreturn function list to separate fileJosh Poimboeuf3-44/+50
This makes it a little cleaner and easier to maintain. Suggested-by: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lore.kernel.org/r/cecacf07a69a244c74474c18b7652627de67a528.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-05-16objtool: Remove superfluous global_noreturns entriesJosh Poimboeuf1-2/+0
lbug_with_loc() no longer exists, and resume_play_dead() is static (objtool only checks globals and weaks). Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lore.kernel.org/r/2725d7f2ccc2361c6903de9ebaa2b5bb304f7ac2.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-05-16objtool: Ignore exc_double_fault() __noreturn warningsJosh Poimboeuf1-1/+30
This is a hack, but it works for now. Problem is, exc_double_fault() may or may not return, depending on whether CONFIG_X86_ESPFIX64 is set. But objtool has no visibility to the kernel config. "Fix" it by silencing the exc_double_fault() __noreturn warning. This removes the following warning: vmlinux.o: warning: objtool: xenpv_exc_double_fault+0xd: exc_double_fault() is missing a __noreturn annotation Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lore.kernel.org/r/a45b085071d3a7d049a20f9e78754452336ecbe8.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-05-16objtool: Detect missing __noreturn annotationsJosh Poimboeuf2-1/+19
Most "unreachable instruction" warnings these days seem to actually be the result of a missing __noreturn annotation. Add an explicit check for that. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lore.kernel.org/r/6e2b93d8c65eaed6c4166a358269dc0ef01f890c.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-05-16objtool: Include backtrace in verbose modeJosh Poimboeuf3-24/+20
Include backtrace in verbose mode. This makes it easy to gather all the information needed for diagnosing objtool warnings. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lore.kernel.org/r/c255224fabcf7e64bac232fec1c77c9fc2d7d7ab.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-05-16objtool: Add verbose option for disassembling affected functionsJosh Poimboeuf4-0/+88
When a warning is associated with a function, add an option to disassemble that function. This makes it easier for reporters to submit the information needed to diagnose objtool warnings. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lore.kernel.org/r/dd0fe13428ede186f09c74059a8001f4adcea5fc.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-05-16objtool: Limit unreachable warnings to once per functionJosh Poimboeuf3-3/+10
Unreachable instruction warnings are limited to once per object file. That no longer makes sense for vmlinux validation, which might have more unreachable instructions lurking in other places. Change it to once per function. Note this affects some other (much rarer) non-fatal warnings as well. In general I think one-warning-per-function makes sense, as related warnings can accumulate quickly and we want to eventually get back to failing the build with -Werror anyway. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lore.kernel.org/r/9d38f881bfc34e031c74e4e90064ccb3e49f599a.1681853186.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-05-10x86/alternative: Support relocations in alternativesPeter Zijlstra1-7/+1
A little while ago someone (Kirill) ran into the whole 'alternatives don't do relocations nonsense' again and I got annoyed enough to actually look at the code. Since the whole alternative machinery already fully decodes the instructions it is simple enough to adjust immediates and displacement when needed. Specifically, the immediates for IP modifying instructions (JMP, CALL, Jcc) and the displacement for RIP-relative instructions. [ bp: Massage comment some more and get rid of third loop in apply_relocation(). ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230208171431.313857925@infradead.org
2023-04-29Merge tag 'objtool-core-2023-04-27' of ↵Linus Torvalds8-271/+290
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molnar: - Mark arch_cpu_idle_dead() __noreturn, make all architectures & drivers that did this inconsistently follow this new, common convention, and fix all the fallout that objtool can now detect statically - Fix/improve the ORC unwinder becoming unreliable due to UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK and UNWIND_HINT_UNDEFINED to resolve it - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code - Generate ORC data for __pfx code - Add more __noreturn annotations to various kernel startup/shutdown and panic functions - Misc improvements & fixes * tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) x86/hyperv: Mark hv_ghcb_terminate() as noreturn scsi: message: fusion: Mark mpt_halt_firmware() __noreturn x86/cpu: Mark {hlt,resume}_play_dead() __noreturn btrfs: Mark btrfs_assertfail() __noreturn objtool: Include weak functions in global_noreturns check cpu: Mark nmi_panic_self_stop() __noreturn cpu: Mark panic_smp_self_stop() __noreturn arm64/cpu: Mark cpu_park_loop() and friends __noreturn x86/head: Mark *_start_kernel() __noreturn init: Mark start_kernel() __noreturn init: Mark [arch_call_]rest_init() __noreturn objtool: Generate ORC data for __pfx code x86/linkage: Fix padding for typed functions objtool: Separate prefix code from stack validation code objtool: Remove superfluous dead_end_function() check objtool: Add symbol iteration helpers objtool: Add WARN_INSN() scripts/objdump-func: Support multiple functions context_tracking: Fix KCSAN noinstr violation objtool: Add stackleak instrumentation to uaccess safe list ...
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-07 19:51:17 +0300