From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org, jpoimboe@redhat.com, andrew.cooper3@citrix.com
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
alexei.starovoitov@gmail.com, ndesaulniers@google.com,
bpf@vger.kernel.org
Subject: [PATCH v3 01/16] objtool: Classify symbols
Date: Tue, 26 Oct 2021 14:01:33 +0200 [thread overview]
Message-ID: <20211026120309.658539311@infradead.org> (raw)
In-Reply-To: 20211026120132.613201817@infradead.org
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@infradead.org>
---
tools/objtool/check.c | 34 ++++++++++++++++++++++------------
tools/objtool/include/objtool/elf.h | 5 ++++-
2 files changed, 26 insertions(+), 13 deletions(-)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1012,8 +1012,7 @@ 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);
@@ -1027,7 +1026,7 @@ static void add_call_dest(struct objtool
insn->type = sibling ? INSN_RETURN : INSN_NOP;
}
- 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);
@@ -1077,7 +1076,7 @@ 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.
@@ -1218,7 +1217,7 @@ 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.
@@ -1919,17 +1918,28 @@ 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;
}
}
@@ -1995,7 +2005,7 @@ 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;
@@ -2053,9 +2063,9 @@ 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
@@ -55,7 +55,10 @@ struct symbol {
unsigned int len;
struct symbol *pfunc, *cfunc, *alias;
bool uaccess_safe;
- bool static_call_tramp;
+ u8 static_call_tramp : 1;
+ u8 retpoline_thunk : 1;
+ u8 fentry : 1;
+ u8 kcov : 1;
struct list_head pv_target;
};
next prev parent reply other threads:[~2021-10-26 12:08 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-26 12:01 [PATCH v3 00/16] x86: Rewrite the retpoline rewrite logic Peter Zijlstra
2021-10-26 12:01 ` Peter Zijlstra [this message]
2021-10-28 3:58 ` [PATCH v3 01/16] objtool: Classify symbols Josh Poimboeuf
2021-10-29 8:03 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 02/16] objtool: Explicitly avoid self modifying code in .altinstr_replacement Peter Zijlstra
2021-10-28 4:01 ` Josh Poimboeuf
2021-10-29 8:03 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 03/16] objtool: Shrink struct instruction Peter Zijlstra
2021-10-29 8:03 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 04/16] objtool,x86: Replace alternatives with .retpoline_sites Peter Zijlstra
2021-10-29 8:03 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 05/16] x86/retpoline: Remove unused replacement symbols Peter Zijlstra
2021-10-29 8:03 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 06/16] x86/asm: Fix register order Peter Zijlstra
2021-10-29 8:03 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 07/16] x86/asm: Fixup odd GEN-for-each-reg.h usage Peter Zijlstra
2021-10-29 8:03 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 08/16] x86/retpoline: Move the retpoline thunk declarations to nospec-branch.h Peter Zijlstra
2021-10-29 8:03 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 09/16] x86/retpoline: Create a retpoline thunk array Peter Zijlstra
2021-10-29 8:03 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 10/16] x86/alternative: Implement .retpoline_sites support Peter Zijlstra
2021-10-27 17:38 ` Borislav Petkov
2021-10-27 19:10 ` Peter Zijlstra
2021-10-29 8:02 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 11/16] x86/alternative: Handle Jcc __x86_indirect_thunk_\reg Peter Zijlstra
2021-10-28 9:29 ` Borislav Petkov
2021-10-29 8:02 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 12/16] x86/alternative: Try inline spectre_v2=retpoline,amd Peter Zijlstra
2021-10-29 8:02 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 13/16] x86/alternative: Add debug prints to apply_retpolines() Peter Zijlstra
2021-10-29 8:02 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 14/16] x86,bugs: Unconditionally allow spectre_v2=retpoline,amd Peter Zijlstra
2021-10-29 8:02 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 15/16] bpf, x86: Simplify computing label offsets Peter Zijlstra
2021-10-29 8:02 ` [tip: objtool/core] bpf,x86: " tip-bot2 for Peter Zijlstra
2021-10-26 12:01 ` [PATCH v3 16/16] bpf,x86: Respect X86_FEATURE_RETPOLINE* Peter Zijlstra
2021-10-29 8:02 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-10-26 18:26 ` [PATCH v3 00/16] x86: Rewrite the retpoline rewrite logic Alexei Starovoitov
2021-10-26 18:45 ` Peter Zijlstra
2021-10-26 20:00 ` Alexei Starovoitov
2021-10-26 21:05 ` Peter Zijlstra
2021-10-26 21:05 ` Alexei Starovoitov
2021-10-27 9:00 ` Peter Zijlstra
2021-10-27 17:32 ` Alexei Starovoitov
2021-10-28 5:17 ` Josh Poimboeuf
2021-10-28 17:43 ` Borislav Petkov
2021-10-29 12:43 ` Miroslav Benes
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