This is a note to let you know that I've just added the patch titled
objtool: Classify symbols
to the 5.15-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-classify-symbols.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Tue Jul 12 05:06:57 PM CEST 2022
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Tue, 26 Oct 2021 14:01:33 +0200
Subject: objtool: Classify symbols
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
commit 1739c66eb7bd5f27f1b69a5a26e10e8327d1e136 upstream.
In order to avoid calling str*cmp() on symbol names, over and over, do
them all once upfront and store the result.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Tested-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211026120309.658539311@xxxxxxxxxxxxx
[cascardo: no pv_target on struct symbol, because of missing
db2b0c5d7b6f19b3c2cab08c531b65342eb5252b]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/objtool/check.c | 34 ++++++++++++++++++++++------------
tools/objtool/include/objtool/elf.h | 7 +++++--
2 files changed, 27 insertions(+), 14 deletions(-)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -859,8 +859,7 @@ static void add_call_dest(struct objtool
* so they need a little help, NOP out any KCOV calls from noinstr
* text.
*/
- if (insn->sec->noinstr &&
- !strncmp(insn->call_dest->name, "__sanitizer_cov_", 16)) {
+ if (insn->sec->noinstr && insn->call_dest->kcov) {
if (reloc) {
reloc->type = R_NONE;
elf_write_reloc(file->elf, reloc);
@@ -884,7 +883,7 @@ static void add_call_dest(struct objtool
}
}
- if (mcount && !strcmp(insn->call_dest->name, "__fentry__")) {
+ if (mcount && insn->call_dest->fentry) {
if (sibling)
WARN_FUNC("Tail call to __fentry__ !?!?", insn->sec, insn->offset);
@@ -934,7 +933,7 @@ static int add_jump_destinations(struct
} else if (reloc->sym->type == STT_SECTION) {
dest_sec = reloc->sym->sec;
dest_off = arch_dest_reloc_offset(reloc->addend);
- } else if (arch_is_retpoline(reloc->sym)) {
+ } else if (reloc->sym->retpoline_thunk) {
/*
* Retpoline jumps are really dynamic jumps in
* disguise, so convert them accordingly.
@@ -1075,7 +1074,7 @@ static int add_call_destinations(struct
add_call_dest(file, insn, dest, false);
- } else if (arch_is_retpoline(reloc->sym)) {
+ } else if (reloc->sym->retpoline_thunk) {
/*
* Retpoline calls are really dynamic calls in
* disguise, so convert them accordingly.
@@ -1759,17 +1758,28 @@ static int read_intra_function_calls(str
return 0;
}
-static int read_static_call_tramps(struct objtool_file *file)
+static int classify_symbols(struct objtool_file *file)
{
struct section *sec;
struct symbol *func;
for_each_sec(file, sec) {
list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->bind == STB_GLOBAL &&
- !strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
+ if (func->bind != STB_GLOBAL)
+ continue;
+
+ if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
strlen(STATIC_CALL_TRAMP_PREFIX_STR)))
func->static_call_tramp = true;
+
+ if (arch_is_retpoline(func))
+ func->retpoline_thunk = true;
+
+ if (!strcmp(func->name, "__fentry__"))
+ func->fentry = true;
+
+ if (!strncmp(func->name, "__sanitizer_cov_", 16))
+ func->kcov = true;
}
}
@@ -1831,7 +1841,7 @@ static int decode_sections(struct objtoo
/*
* Must be before add_{jump_call}_destination.
*/
- ret = read_static_call_tramps(file);
+ ret = classify_symbols(file);
if (ret)
return ret;
@@ -1889,9 +1899,9 @@ static int decode_sections(struct objtoo
static bool is_fentry_call(struct instruction *insn)
{
- if (insn->type == INSN_CALL && insn->call_dest &&
- insn->call_dest->type == STT_NOTYPE &&
- !strcmp(insn->call_dest->name, "__fentry__"))
+ if (insn->type == INSN_CALL &&
+ insn->call_dest &&
+ insn->call_dest->fentry)
return true;
return false;
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -54,8 +54,11 @@ struct symbol {
unsigned long offset;
unsigned int len;
struct symbol *pfunc, *cfunc, *alias;
- bool uaccess_safe;
- bool static_call_tramp;
+ u8 uaccess_safe : 1;
+ u8 static_call_tramp : 1;
+ u8 retpoline_thunk : 1;
+ u8 fentry : 1;
+ u8 kcov : 1;
};
struct reloc {
Patches currently in stable-queue which might be from peterz@xxxxxxxxxxxxx are
queue-5.15/x86-sev-avoid-using-__x86_return_thunk.patch
queue-5.15/x86-ftrace-use-alternative-ret-encoding.patch
queue-5.15/objtool-re-add-unwind_hint_-save_restore.patch
queue-5.15/x86-bugs-add-retbleed-ibpb.patch
queue-5.15/x86-bugs-enable-stibp-for-jmp2ret.patch
queue-5.15/x86-retpoline-cleanup-some-ifdefery.patch
queue-5.15/kvm-vmx-flatten-__vmx_vcpu_run.patch
queue-5.15/x86-kvm-vmx-make-noinstr-clean.patch
queue-5.15/objtool-x86-replace-alternatives-with-.retpoline_sites.patch
queue-5.15/x86-retbleed-add-fine-grained-kconfig-knobs.patch
queue-5.15/x86-cpu-amd-add-spectral-chicken.patch
queue-5.15/kvm-vmx-fix-ibrs-handling-after-vmexit.patch
queue-5.15/kvm-vmx-prevent-guest-rsb-poisoning-attacks-with-eibrs.patch
queue-5.15/x86-vsyscall_emu-64-don-t-use-ret-in-vsyscall-emulation.patch
queue-5.15/x86-add-magic-amd-return-thunk.patch
queue-5.15/x86-bugs-keep-a-per-cpu-ia32_spec_ctrl-value.patch
queue-5.15/x86-objtool-create-.return_sites.patch
queue-5.15/x86-alternative-handle-jcc-__x86_indirect_thunk_-reg.patch
queue-5.15/x86-kvm-fix-setcc-emulation-for-return-thunks.patch
queue-5.15/x86-retpoline-swizzle-retpoline-thunk.patch
queue-5.15/x86-speculation-fix-firmware-entry-spec_ctrl-handling.patch
queue-5.15/x86-retpoline-remove-unused-replacement-symbols.patch
queue-5.15/x86-speculation-add-spectre_v2-ibrs-option-to-support-kernel-ibrs.patch
queue-5.15/x86-xen-add-untrain_ret.patch
queue-5.15/bpf-x86-respect-x86_feature_retpoline.patch
queue-5.15/x86-undo-return-thunk-damage.patch
queue-5.15/x86-entry-avoid-very-early-ret.patch
queue-5.15/x86-entry-move-push_and_clear_regs-back-into-error_entry.patch
queue-5.15/x86-retpoline-create-a-retpoline-thunk-array.patch
queue-5.15/x86-asm-fix-register-order.patch
queue-5.15/x86-speculation-fill-rsb-on-vmexit-for-ibrs.patch
queue-5.15/objtool-add-entry-unret-validation.patch
queue-5.15/objtool-shrink-struct-instruction.patch
queue-5.15/kvm-vmx-convert-launched-argument-to-flags.patch
queue-5.15/x86-bpf-use-alternative-ret-encoding.patch
queue-5.15/x86-common-stamp-out-the-stepping-madness.patch
queue-5.15/x86-bugs-split-spectre_v2_select_mitigation-and-spectre_v2_user_select_mitigation.patch
queue-5.15/x86-bugs-report-intel-retbleed-vulnerability.patch
queue-5.15/bpf-x86-simplify-computing-label-offsets.patch
queue-5.15/x86-cpufeatures-move-retpoline-flags-to-word-11.patch
queue-5.15/x86-speculation-fix-spec_ctrl-write-on-smt-state-change.patch
queue-5.15/x86-retpoline-use-mfunction-return.patch
queue-5.15/x86-xen-rename-sys-entry-points.patch
queue-5.15/x86-bugs-optimize-spec_ctrl-msr-writes.patch
queue-5.15/x86-bugs-report-amd-retbleed-vulnerability.patch
queue-5.15/x86-static_call-use-alternative-ret-encoding.patch
queue-5.15/x86-speculation-fix-rsb-filling-with-config_retpoline-n.patch
queue-5.15/x86-asm-fixup-odd-gen-for-each-reg.h-usage.patch
queue-5.15/x86-alternative-add-debug-prints-to-apply_retpolines.patch
queue-5.15/x86-use-return-thunk-in-asm-code.patch
queue-5.15/objtool-classify-symbols.patch
queue-5.15/intel_idle-disable-ibrs-during-long-idle.patch
queue-5.15/x86-retpoline-move-the-retpoline-thunk-declarations-to-nospec-branch.h.patch
queue-5.15/x86-alternative-implement-.retpoline_sites-support.patch
queue-5.15/x86-alternative-try-inline-spectre_v2-retpoline-amd.patch
queue-5.15/x86-entry-remove-skip_r11rcx.patch
queue-5.15/objtool-explicitly-avoid-self-modifying-code-in-.altinstr_replacement.patch
queue-5.15/x86-speculation-use-cached-host-spec_ctrl-value-for-guest-entry-exit.patch
queue-5.15/x86-bugs-add-amd-retbleed-boot-parameter.patch
queue-5.15/x86-entry-add-kernel-ibrs-implementation.patch
queue-5.15/objtool-treat-.text.__x86.-as-noinstr.patch
queue-5.15/objtool-introduce-cfi-hash.patch
queue-5.15/objtool-default-ignore-int3-for-unreachable.patch
queue-5.15/objtool-update-retpoline-validation.patch
