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Diffstat (limited to 'tools/objtool/arch/x86/special.c')
-rw-r--r--tools/objtool/arch/x86/special.c48
1 files changed, 15 insertions, 33 deletions
diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c
index 9c1c9df09aaa..e817a3fff449 100644
--- a/tools/objtool/arch/x86/special.c
+++ b/tools/objtool/arch/x86/special.c
@@ -3,11 +3,13 @@
#include <objtool/special.h>
#include <objtool/builtin.h>
+#include <objtool/warn.h>
+#include <asm/cpufeatures.h>
-#define X86_FEATURE_POPCNT (4 * 32 + 23)
-#define X86_FEATURE_SMAP (9 * 32 + 20)
+/* cpu feature name array generated from cpufeatures.h */
+#include "cpu-feature-names.c"
-void arch_handle_alternative(unsigned short feature, struct special_alt *alt)
+void arch_handle_alternative(struct special_alt *alt)
{
static struct special_alt *group, *prev;
@@ -31,34 +33,6 @@ void arch_handle_alternative(unsigned short feature, struct special_alt *alt)
} else group = alt;
prev = alt;
-
- switch (feature) {
- case X86_FEATURE_SMAP:
- /*
- * If UACCESS validation is enabled; force that alternative;
- * otherwise force it the other way.
- *
- * What we want to avoid is having both the original and the
- * alternative code flow at the same time, in that case we can
- * find paths that see the STAC but take the NOP instead of
- * CLAC and the other way around.
- */
- if (opts.uaccess)
- alt->skip_orig = true;
- else
- alt->skip_alt = true;
- break;
- case X86_FEATURE_POPCNT:
- /*
- * It has been requested that we don't validate the !POPCNT
- * feature path which is a "very very small percentage of
- * machines".
- */
- alt->skip_orig = true;
- break;
- default:
- break;
- }
}
bool arch_support_alt_relocation(struct special_alt *special_alt,
@@ -119,7 +93,7 @@ struct reloc *arch_find_switch_table(struct objtool_file *file,
/* look for a relocation which references .rodata */
text_reloc = find_reloc_by_dest_range(file->elf, insn->sec,
insn->offset, insn->len);
- if (!text_reloc || text_reloc->sym->type != STT_SECTION ||
+ if (!text_reloc || !is_sec_sym(text_reloc->sym) ||
!text_reloc->sym->sec->rodata)
return NULL;
@@ -156,9 +130,17 @@ struct reloc *arch_find_switch_table(struct objtool_file *file,
* indicates a rare GCC quirk/bug which can leave dead
* code behind.
*/
- if (reloc_type(text_reloc) == R_X86_64_PC32)
+ if (!file->ignore_unreachables && reloc_type(text_reloc) == R_X86_64_PC32) {
+ WARN_INSN(insn, "ignoring unreachables due to jump table quirk");
file->ignore_unreachables = true;
+ }
*table_size = 0;
return rodata_reloc;
}
+
+const char *arch_cpu_feature_name(int feature_number)
+{
+ return (feature_number < ARRAY_SIZE(cpu_feature_names)) ?
+ cpu_feature_names[feature_number] : NULL;
+}