diff mbox series

[bpf-next,02/17] objtool: Classify symbols

Message ID 20211027085520.169316183@infradead.org (mailing list archive)
State Not Applicable
Delegated to: BPF
Headers show
Series x86: Rewrite the retpoline rewrite logic | expand

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Context Check Description
netdev/cover_letter success Series has a cover letter
netdev/fixes_present success Fixes tag not required for -next series
netdev/patch_count fail Series longer than 15 patches (and no cover letter)
netdev/tree_selection success Clearly marked for bpf-next
netdev/subject_prefix success Link
netdev/cc_maintainers warning 13 maintainers not CCed: john.fastabend@gmail.com mbenes@suse.cz daniel@iogearbox.net yhs@fb.com netdev@vger.kernel.org songliubraving@fb.com mingo@kernel.org bp@suse.de kafai@fb.com kpsingh@kernel.org jpoimboe@redhat.com ast@kernel.org andrii@kernel.org
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success No Fixes tag
netdev/checkpatch warning CHECK: From:/Signed-off-by: email comments mismatch: 'From: Peter Zijlstra <peterz@infradead.org>' != 'Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>'
netdev/build_allmodconfig_warn success Errors and warnings before: 17693 this patch: 17693
netdev/header_inline success No static functions without inline keyword in header files
bpf/vmtest-bpf-next-PR fail PR summary
bpf/vmtest-bpf-next fail VM_Test

Commit Message

Peter Zijlstra Oct. 27, 2021, 8:52 a.m. UTC
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(-)
diff mbox series

Patch

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -857,8 +857,7 @@  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);
@@ -872,7 +871,7 @@  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);
 
@@ -922,7 +921,7 @@  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.
@@ -1063,7 +1062,7 @@  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.
@@ -1747,17 +1746,28 @@  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;
 		}
 	}
 
@@ -1819,7 +1829,7 @@  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;
 
@@ -1877,9 +1887,9 @@  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
@@ -56,7 +56,10 @@  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 reloc {