diff options
Diffstat (limited to '0089-x86-ftrace-Remove-OBJECT_FILES_NON_STANDARD-usage.patch')
| -rw-r--r-- | 0089-x86-ftrace-Remove-OBJECT_FILES_NON_STANDARD-usage.patch | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/0089-x86-ftrace-Remove-OBJECT_FILES_NON_STANDARD-usage.patch b/0089-x86-ftrace-Remove-OBJECT_FILES_NON_STANDARD-usage.patch new file mode 100644 index 000000000000..dc788b81ff6b --- /dev/null +++ b/0089-x86-ftrace-Remove-OBJECT_FILES_NON_STANDARD-usage.patch @@ -0,0 +1,136 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Josh Poimboeuf <jpoimboe@kernel.org> +Date: Fri, 3 Jun 2022 08:04:44 -0700 +Subject: [PATCH] x86/ftrace: Remove OBJECT_FILES_NON_STANDARD usage + +[ Upstream commit 7b6c7a877cc616bc7dc9cd39646fe454acbed48b ] + +The file-wide OBJECT_FILES_NON_STANDARD annotation is used with +CONFIG_FRAME_POINTER to tell objtool to skip the entire file when frame +pointers are enabled. However that annotation is now deprecated because +it doesn't work with IBT, where objtool runs on vmlinux.o instead of +individual translation units. + +Instead, use more fine-grained function-specific annotations: + +- The 'save_mcount_regs' macro does funny things with the frame pointer. + Use STACK_FRAME_NON_STANDARD_FP to tell objtool to ignore the + functions using it. + +- The return_to_handler() "function" isn't actually a callable function. + Instead of being called, it's returned to. The real return address + isn't on the stack, so unwinding is already doomed no matter which + unwinder is used. So just remove the STT_FUNC annotation, telling + objtool to ignore it. That also removes the implicit + ANNOTATE_NOENDBR, which now needs to be made explicit. + +Fixes the following warning: + + vmlinux.o: warning: objtool: __fentry__+0x16: return with modified stack frame + +Fixes: ed53a0d97192 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls") +Reported-by: kernel test robot <lkp@intel.com> +Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> +Link: https://lore.kernel.org/r/b7a7a42fe306aca37826043dac89e113a1acdbac.1654268610.git.jpoimboe@kernel.org +Signed-off-by: Sasha Levin <sashal@kernel.org> +--- + arch/x86/kernel/Makefile | 4 ---- + arch/x86/kernel/ftrace_64.S | 11 ++++++++--- + include/linux/objtool.h | 6 ++++++ + tools/include/linux/objtool.h | 6 ++++++ + 4 files changed, 20 insertions(+), 7 deletions(-) + +diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile +index c41ef42adbe8a3b13d10442b3d3b590b1ac40836..25828e4c62375007b3efd2fa392604b8c85636a4 100644 +--- a/arch/x86/kernel/Makefile ++++ b/arch/x86/kernel/Makefile +@@ -36,10 +36,6 @@ KCSAN_SANITIZE := n + + OBJECT_FILES_NON_STANDARD_test_nx.o := y + +-ifdef CONFIG_FRAME_POINTER +-OBJECT_FILES_NON_STANDARD_ftrace_$(BITS).o := y +-endif +- + # If instrumentation of this dir is enabled, boot hangs during first second. + # Probably could be more selective here, but note that files related to irqs, + # boot, dumpstack/stacktrace, etc are either non-interesting or can lead to +diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S +index 4ec13608d3c62bd8acae0d897b264cde3eb41e14..dfeb227de5617c6d55ad6ace1f321b7ac87b6a70 100644 +--- a/arch/x86/kernel/ftrace_64.S ++++ b/arch/x86/kernel/ftrace_64.S +@@ -175,6 +175,7 @@ SYM_INNER_LABEL(ftrace_caller_end, SYM_L_GLOBAL) + + jmp ftrace_epilogue + SYM_FUNC_END(ftrace_caller); ++STACK_FRAME_NON_STANDARD_FP(ftrace_caller) + + SYM_FUNC_START(ftrace_epilogue) + /* +@@ -282,6 +283,7 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL) + jmp ftrace_epilogue + + SYM_FUNC_END(ftrace_regs_caller) ++STACK_FRAME_NON_STANDARD_FP(ftrace_regs_caller) + + + #else /* ! CONFIG_DYNAMIC_FTRACE */ +@@ -311,10 +313,14 @@ trace: + jmp ftrace_stub + SYM_FUNC_END(__fentry__) + EXPORT_SYMBOL(__fentry__) ++STACK_FRAME_NON_STANDARD_FP(__fentry__) ++ + #endif /* CONFIG_DYNAMIC_FTRACE */ + + #ifdef CONFIG_FUNCTION_GRAPH_TRACER +-SYM_FUNC_START(return_to_handler) ++SYM_CODE_START(return_to_handler) ++ UNWIND_HINT_EMPTY ++ ANNOTATE_NOENDBR + subq $16, %rsp + + /* Save the return values */ +@@ -339,7 +345,6 @@ SYM_FUNC_START(return_to_handler) + int3 + .Ldo_rop: + mov %rdi, (%rsp) +- UNWIND_HINT_FUNC + RET +-SYM_FUNC_END(return_to_handler) ++SYM_CODE_END(return_to_handler) + #endif +diff --git a/include/linux/objtool.h b/include/linux/objtool.h +index 586d35720f135f62b9d7434beccacb2e22a5bd2d..c81ea2264ad8a74b765f5649f81ee1198d7704dd 100644 +--- a/include/linux/objtool.h ++++ b/include/linux/objtool.h +@@ -141,6 +141,12 @@ struct unwind_hint { + .popsection + .endm + ++.macro STACK_FRAME_NON_STANDARD_FP func:req ++#ifdef CONFIG_FRAME_POINTER ++ STACK_FRAME_NON_STANDARD \func ++#endif ++.endm ++ + .macro ANNOTATE_NOENDBR + .Lhere_\@: + .pushsection .discard.noendbr +diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h +index 586d35720f135f62b9d7434beccacb2e22a5bd2d..c81ea2264ad8a74b765f5649f81ee1198d7704dd 100644 +--- a/tools/include/linux/objtool.h ++++ b/tools/include/linux/objtool.h +@@ -141,6 +141,12 @@ struct unwind_hint { + .popsection + .endm + ++.macro STACK_FRAME_NON_STANDARD_FP func:req ++#ifdef CONFIG_FRAME_POINTER ++ STACK_FRAME_NON_STANDARD \func ++#endif ++.endm ++ + .macro ANNOTATE_NOENDBR + .Lhere_\@: + .pushsection .discard.noendbr |