Messages in this thread Patch in this message | | | Date | Fri, 02 Sep 2022 15:07:01 +0200 | From | Peter Zijlstra <> | Subject | [PATCH v2 36/59] ftrace: Add HAVE_DYNAMIC_FTRACE_NO_PATCHABLE |
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From: Peter Zijlstra (Intel) <peterz@infradead.org>
x86 will shortly start using -fpatchable-function-entry for purposes other than ftrace, make sure the __patchable_function_entry section isn't merged in the mcount_loc section.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- include/asm-generic/vmlinux.lds.h | 11 ++++++++++- kernel/trace/Kconfig | 6 ++++++ tools/objtool/check.c | 3 ++- 3 files changed, 18 insertions(+), 2 deletions(-)
--- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -159,6 +159,14 @@ #define MEM_DISCARD(sec) *(.mem##sec) #endif +#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_NO_PATCHABLE +#define KEEP_PATCHABLE KEEP(*(__patchable_function_entries)) +#define PATCHABLE_DISCARDS +#else +#define KEEP_PATCHABLE +#define PATCHABLE_DISCARDS *(__patchable_function_entries) +#endif + #ifdef CONFIG_FTRACE_MCOUNT_RECORD /* * The ftrace call sites are logged to a section whose name depends on the @@ -177,7 +185,7 @@ #define MCOUNT_REC() . = ALIGN(8); \ __start_mcount_loc = .; \ KEEP(*(__mcount_loc)) \ - KEEP(*(__patchable_function_entries)) \ + KEEP_PATCHABLE \ __stop_mcount_loc = .; \ ftrace_stub_graph = ftrace_stub; \ ftrace_ops_list_func = arch_ftrace_ops_list_func; @@ -1029,6 +1037,7 @@ #define COMMON_DISCARDS \ SANITIZER_DISCARDS \ + PATCHABLE_DISCARDS \ *(.discard) \ *(.discard.*) \ *(.modinfo) \ --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -51,6 +51,12 @@ config HAVE_DYNAMIC_FTRACE_WITH_ARGS This allows for use of regs_get_kernel_argument() and kernel_stack_pointer(). +config HAVE_DYNAMIC_FTRACE_NO_PATCHABLE + bool + help + If the architecture generates __patchable_function_entries sections + but does not want them included in the ftrace locations. + config HAVE_FTRACE_MCOUNT_RECORD bool help --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -4196,7 +4196,8 @@ static int validate_ibt(struct objtool_f !strcmp(sec->name, "__bug_table") || !strcmp(sec->name, "__ex_table") || !strcmp(sec->name, "__jump_table") || - !strcmp(sec->name, "__mcount_loc")) + !strcmp(sec->name, "__mcount_loc") || + strstr(sec->name, "__patchable_function_entries")) continue; list_for_each_entry(reloc, &sec->reloc->reloc_list, list)
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