This is a note to let you know that I've just added the patch titled
objtool, modules: Discard objtool annotation sections for modules
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
objtool-modules-discard-objtool-annotation-sections-for-modules.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e390f9a9689a42f477a6073e2e7df530a4c1b740 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Date: Wed, 1 Mar 2017 12:04:44 -0600
Subject: objtool, modules: Discard objtool annotation sections for modules
From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
commit e390f9a9689a42f477a6073e2e7df530a4c1b740 upstream.
The '__unreachable' and '__func_stack_frame_non_standard' sections are
only used at compile time. They're discarded for vmlinux but they
should also be discarded for modules.
Since this is a recurring pattern, prefix the section names with
".discard.". It's a nice convention and vmlinux.lds.h already discards
such sections.
Also remove the 'a' (allocatable) flag from the __unreachable section
since it doesn't make sense for a discarded section.
Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Jessica Yu <jeyu@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends")
Link: http://lkml.kernel.org/r/20170301180444.lhd53c5tibc4ns77@treble
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
[dwmw2: Remove the unreachable part in backporting since it's not here yet]
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/frame.h | 2 +-
scripts/mod/modpost.c | 1 +
scripts/module-common.lds | 5 ++++-
tools/objtool/builtin-check.c | 2 +-
4 files changed, 7 insertions(+), 3 deletions(-)
--- a/include/linux/frame.h
+++ b/include/linux/frame.h
@@ -11,7 +11,7 @@
* For more information, see tools/objtool/Documentation/stack-validation.txt.
*/
#define STACK_FRAME_NON_STANDARD(func) \
- static void __used __section(__func_stack_frame_non_standard) \
+ static void __used __section(.discard.func_stack_frame_non_standard) \
*__func_stack_frame_non_standard_##func = func
#else /* !CONFIG_STACK_VALIDATION */
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -838,6 +838,7 @@ static const char *const section_white_l
".cmem*", /* EZchip */
".fmt_slot*", /* EZchip */
".gnu.lto*",
+ ".discard.*",
NULL
};
--- a/scripts/module-common.lds
+++ b/scripts/module-common.lds
@@ -4,7 +4,10 @@
* combine them automatically.
*/
SECTIONS {
- /DISCARD/ : { *(.discard) }
+ /DISCARD/ : {
+ *(.discard)
+ *(.discard.*)
+ }
__ksymtab 0 : { *(SORT(___ksymtab+*)) }
__ksymtab_gpl 0 : { *(SORT(___ksymtab_gpl+*)) }
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -1229,7 +1229,7 @@ int cmd_check(int argc, const char **arg
INIT_LIST_HEAD(&file.insn_list);
hash_init(file.insn_hash);
- file.whitelist = find_section_by_name(file.elf, "__func_stack_frame_non_standard");
+ file.whitelist = find_section_by_name(file.elf, ".discard.func_stack_frame_non_standard");
file.rodata = find_section_by_name(file.elf, ".rodata");
file.ignore_unreachables = false;
file.c_file = find_section_by_name(file.elf, ".comment");
Patches currently in stable-queue which might be from jpoimboe@xxxxxxxxxx are
queue-4.9/x86-spectre-add-boot-time-option-to-select-spectre-v2-mitigation.patch
queue-4.9/x86-retpoline-irq32-convert-assembler-indirect-jumps.patch
queue-4.9/objtool-detect-jumps-to-retpoline-thunks.patch
queue-4.9/x86-retpoline-hyperv-convert-assembler-indirect-jumps.patch
queue-4.9/x86-retpoline-entry-convert-entry-assembler-indirect-jumps.patch
queue-4.9/x86-asm-use-register-variable-to-get-stack-pointer-value.patch
queue-4.9/x86-cpufeatures-add-x86_bug_cpu_insecure.patch
queue-4.9/objtool-modules-discard-objtool-annotation-sections-for-modules.patch
queue-4.9/x86-cpufeatures-make-cpu-bugs-sticky.patch
queue-4.9/x86-retpoline-ftrace-convert-ftrace-assembler-indirect-jumps.patch
queue-4.9/objtool-allow-alternatives-to-be-ignored.patch
queue-4.9/x86-retpoline-crypto-convert-crypto-assembler-indirect-jumps.patch
queue-4.9/selftests-x86-add-test_vsyscall.patch
queue-4.9/x86-retpoline-xen-convert-xen-hypercall-indirect-jumps.patch
queue-4.9/x86-cpu-merge-bugs.c-and-bugs_64.c.patch
queue-4.9/x86-retpoline-checksum32-convert-assembler-indirect-jumps.patch
queue-4.9/x86-retpoline-fill-return-stack-buffer-on-vmexit.patch
queue-4.9/x86-retpoline-remove-compile-time-warning.patch
queue-4.9/x86-retpoline-add-initial-retpoline-support.patch