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ftrace: Add HAVE_DYNAMIC_FTRACE_NO_PATCHABLE

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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: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220903131154.420467-2-jolsa@kernel.org
This commit is contained in:
Peter Zijlstra (Intel) 2022-09-03 15:11:53 +02:00 committed by Daniel Borkmann
parent bfeb7e399b
commit 9440155ccb
3 changed files with 18 additions and 2 deletions
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11
include/asm-generic/vmlinux.lds.h
View File

@ -154,6 +154,14 @@
#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
@ -172,7 +180,7 @@
#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;
@ -1024,6 +1032,7 @@
#define COMMON_DISCARDS \
SANITIZER_DISCARDS \
PATCHABLE_DISCARDS \
*(.discard) \
*(.discard.*) \
*(.modinfo) \

6
kernel/trace/Kconfig
View File

@ -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

3
tools/objtool/check.c
View File

@ -4113,7 +4113,8 @@ static int validate_ibt(struct objtool_file *file)
!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)