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-rw-r--r--tools/objtool/arch.h2
-rw-r--r--tools/objtool/arch/x86/decode.c18
-rw-r--r--tools/objtool/arch/x86/include/arch_elf.h6
-rw-r--r--tools/objtool/check.c23
-rw-r--r--tools/objtool/elf.c64
-rw-r--r--tools/objtool/elf.h12
-rw-r--r--tools/objtool/orc_gen.c2
7 files changed, 119 insertions, 8 deletions
diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h
index d0969a9328c2..2e2ce089b0e9 100644
--- a/tools/objtool/arch.h
+++ b/tools/objtool/arch.h
@@ -84,4 +84,6 @@ unsigned long arch_jump_destination(struct instruction *insn);
unsigned long arch_dest_reloc_offset(int addend);
+const char *arch_nop_insn(int len);
+
#endif /* _ARCH_H */
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index fe83d4c92825..1967370440b3 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -565,3 +565,21 @@ void arch_initial_func_cfi_state(struct cfi_init_state *state)
state->regs[16].base = CFI_CFA;
state->regs[16].offset = -8;
}
+
+const char *arch_nop_insn(int len)
+{
+ static const char nops[5][5] = {
+ /* 1 */ { 0x90 },
+ /* 2 */ { 0x66, 0x90 },
+ /* 3 */ { 0x0f, 0x1f, 0x00 },
+ /* 4 */ { 0x0f, 0x1f, 0x40, 0x00 },
+ /* 5 */ { 0x0f, 0x1f, 0x44, 0x00, 0x00 },
+ };
+
+ if (len < 1 || len > 5) {
+ WARN("invalid NOP size: %d\n", len);
+ return NULL;
+ }
+
+ return nops[len-1];
+}
diff --git a/tools/objtool/arch/x86/include/arch_elf.h b/tools/objtool/arch/x86/include/arch_elf.h
new file mode 100644
index 000000000000..69cc4264b28a
--- /dev/null
+++ b/tools/objtool/arch/x86/include/arch_elf.h
@@ -0,0 +1,6 @@
+#ifndef _OBJTOOL_ARCH_ELF
+#define _OBJTOOL_ARCH_ELF
+
+#define R_NONE R_X86_64_NONE
+
+#endif /* _OBJTOOL_ARCH_ELF */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 559c1baf9fc5..a2313ecce6d1 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -12,6 +12,7 @@
#include "check.h"
#include "special.h"
#include "warn.h"
+#include "arch_elf.h"
#include <linux/hashtable.h>
#include <linux/kernel.h>
@@ -766,6 +767,24 @@ static int add_call_destinations(struct objtool_file *file)
insn->call_dest = reloc->sym;
/*
+ * Many compilers cannot disable KCOV with a function attribute
+ * 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 (reloc) {
+ reloc->type = R_NONE;
+ elf_write_reloc(file->elf, reloc);
+ }
+
+ elf_write_insn(file->elf, insn->sec,
+ insn->offset, insn->len,
+ arch_nop_insn(insn->len));
+ insn->type = INSN_NOP;
+ }
+
+ /*
* Whatever stack impact regular CALLs have, should be undone
* by the RETURN of the called function.
*
@@ -2740,7 +2759,7 @@ int check(const char *_objname, bool orc)
objname = _objname;
- file.elf = elf_open_read(objname, orc ? O_RDWR : O_RDONLY);
+ file.elf = elf_open_read(objname, O_RDWR);
if (!file.elf)
return 1;
@@ -2801,7 +2820,9 @@ int check(const char *_objname, bool orc)
ret = create_orc_sections(&file);
if (ret < 0)
goto out;
+ }
+ if (file.elf->changed) {
ret = elf_write(file.elf);
if (ret < 0)
goto out;
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 95d86bcb9512..3ddbd66f1a37 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -563,8 +563,10 @@ static int read_relocs(struct elf *elf)
break;
default: return -1;
}
- reloc->sym = find_symbol_by_index(elf, symndx);
+
reloc->sec = sec;
+ reloc->idx = i;
+ reloc->sym = find_symbol_by_index(elf, symndx);
if (!reloc->sym) {
WARN("can't find reloc entry symbol %d for %s",
symndx, sec->name);
@@ -747,6 +749,8 @@ struct section *elf_create_section(struct elf *elf, const char *name,
elf_hash_add(elf->section_hash, &sec->hash, sec->idx);
elf_hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name));
+ elf->changed = true;
+
return sec;
}
@@ -880,11 +884,14 @@ static int elf_rebuild_rela_reloc_section(struct section *sec, int nr)
return 0;
}
-int elf_rebuild_reloc_section(struct section *sec)
+int elf_rebuild_reloc_section(struct elf *elf, struct section *sec)
{
struct reloc *reloc;
int nr;
+ sec->changed = true;
+ elf->changed = true;
+
nr = 0;
list_for_each_entry(reloc, &sec->reloc_list, list)
nr++;
@@ -896,7 +903,54 @@ int elf_rebuild_reloc_section(struct section *sec)
}
}
-int elf_write(const struct elf *elf)
+int elf_write_insn(struct elf *elf, struct section *sec,
+ unsigned long offset, unsigned int len,
+ const char *insn)
+{
+ Elf_Data *data = sec->data;
+
+ if (data->d_type != ELF_T_BYTE || data->d_off) {
+ WARN("write to unexpected data for section: %s", sec->name);
+ return -1;
+ }
+
+ memcpy(data->d_buf + offset, insn, len);
+ elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY);
+
+ elf->changed = true;
+
+ return 0;
+}
+
+int elf_write_reloc(struct elf *elf, struct reloc *reloc)
+{
+ struct section *sec = reloc->sec;
+
+ if (sec->sh.sh_type == SHT_REL) {
+ reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);
+ reloc->rel.r_offset = reloc->offset;
+
+ if (!gelf_update_rel(sec->data, reloc->idx, &reloc->rel)) {
+ WARN_ELF("gelf_update_rel");
+ return -1;
+ }
+ } else {
+ reloc->rela.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);
+ reloc->rela.r_addend = reloc->addend;
+ reloc->rela.r_offset = reloc->offset;
+
+ if (!gelf_update_rela(sec->data, reloc->idx, &reloc->rela)) {
+ WARN_ELF("gelf_update_rela");
+ return -1;
+ }
+ }
+
+ elf->changed = true;
+
+ return 0;
+}
+
+int elf_write(struct elf *elf)
{
struct section *sec;
Elf_Scn *s;
@@ -913,6 +967,8 @@ int elf_write(const struct elf *elf)
WARN_ELF("gelf_update_shdr");
return -1;
}
+
+ sec->changed = false;
}
}
@@ -925,6 +981,8 @@ int elf_write(const struct elf *elf)
return -1;
}
+ elf->changed = false;
+
return 0;
}
diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index 78a2db23b8b6..6cc80a075166 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -67,9 +67,10 @@ struct reloc {
};
struct section *sec;
struct symbol *sym;
- unsigned int type;
unsigned long offset;
+ unsigned int type;
int addend;
+ int idx;
bool jump_table_start;
};
@@ -79,6 +80,7 @@ struct elf {
Elf *elf;
GElf_Ehdr ehdr;
int fd;
+ bool changed;
char *name;
struct list_head sections;
DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
@@ -121,7 +123,11 @@ struct elf *elf_open_read(const char *name, int flags);
struct section *elf_create_section(struct elf *elf, const char *name, size_t entsize, int nr);
struct section *elf_create_reloc_section(struct elf *elf, struct section *base, int reltype);
void elf_add_reloc(struct elf *elf, struct reloc *reloc);
-int elf_write(const struct elf *elf);
+int elf_write_insn(struct elf *elf, struct section *sec,
+ unsigned long offset, unsigned int len,
+ const char *insn);
+int elf_write_reloc(struct elf *elf, struct reloc *reloc);
+int elf_write(struct elf *elf);
void elf_close(struct elf *elf);
struct section *find_section_by_name(const struct elf *elf, const char *name);
@@ -133,7 +139,7 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns
struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
unsigned long offset, unsigned int len);
struct symbol *find_func_containing(struct section *sec, unsigned long offset);
-int elf_rebuild_reloc_section(struct section *sec);
+int elf_rebuild_reloc_section(struct elf *elf, struct section *sec);
#define for_each_sec(file, sec) \
list_for_each_entry(sec, &file->elf->sections, list)
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index 75e08cf0709b..968f55e6dd94 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -222,7 +222,7 @@ int create_orc_sections(struct objtool_file *file)
}
}
- if (elf_rebuild_reloc_section(ip_relocsec))
+ if (elf_rebuild_reloc_section(file->elf, ip_relocsec))
return -1;
return 0;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 15:51:55 +0000