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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.c53
-rw-r--r--tools/objtool/elf.c53
-rw-r--r--tools/objtool/elf.h12
-rw-r--r--tools/objtool/orc_gen.c2
7 files changed, 136 insertions, 10 deletions
diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h
index eda15a5a285e..3c5967748abb 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_rela_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 4b504fc90bbb..9872195f998b 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 5fbb90a80d23..5e0d70a89fb8 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 = rela->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 (rela) {
+ rela->type = R_NONE;
+ elf_write_rela(file->elf, rela);
+ }
+
+ 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.
*
@@ -2190,10 +2209,36 @@ static inline const char *call_dest_name(struct instruction *insn)
return "{dynamic}";
}
+static inline bool noinstr_call_dest(struct symbol *func)
+{
+ /*
+ * We can't deal with indirect function calls at present;
+ * assume they're instrumented.
+ */
+ if (!func)
+ return false;
+
+ /*
+ * If the symbol is from a noinstr section; we good.
+ */
+ if (func->sec->noinstr)
+ return true;
+
+ /*
+ * The __ubsan_handle_*() calls are like WARN(), they only happen when
+ * something 'BAD' happened. At the risk of taking the machine down,
+ * let them proceed to get the message out.
+ */
+ if (!strncmp(func->name, "__ubsan_handle_", 15))
+ return true;
+
+ return false;
+}
+
static int validate_call(struct instruction *insn, struct insn_state *state)
{
if (state->noinstr && state->instr <= 0 &&
- (!insn->call_dest || !insn->call_dest->sec->noinstr)) {
+ !noinstr_call_dest(insn->call_dest)) {
WARN_FUNC("call to %s() leaves .noinstr.text section",
insn->sec, insn->offset, call_dest_name(insn));
return 1;
@@ -2740,13 +2785,13 @@ 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;
INIT_LIST_HEAD(&file.insn_list);
hash_init(file.insn_hash);
- file.c_file = find_section_by_name(file.elf, ".comment");
+ file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment");
file.ignore_unreachables = no_unreachable;
file.hints = false;
@@ -2801,7 +2846,9 @@ 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 84225679f96d..26d11d821941 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -529,8 +529,9 @@ static int read_relas(struct elf *elf)
rela->addend = rela->rela.r_addend;
rela->offset = rela->rela.r_offset;
symndx = GELF_R_SYM(rela->rela.r_info);
- rela->sym = find_symbol_by_index(elf, symndx);
rela->sec = sec;
+ rela->idx = i;
+ rela->sym = find_symbol_by_index(elf, symndx);
if (!rela->sym) {
WARN("can't find rela entry symbol %d for %s",
symndx, sec->name);
@@ -713,6 +714,8 @@ 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;
}
@@ -746,7 +749,7 @@ struct section *elf_create_rela_section(struct elf *elf, struct section *base)
return sec;
}
-int elf_rebuild_rela_section(struct section *sec)
+int elf_rebuild_rela_section(struct elf *elf, struct section *sec)
{
struct rela *rela;
int nr, idx = 0, size;
@@ -763,6 +766,9 @@ int elf_rebuild_rela_section(struct section *sec)
return -1;
}
+ sec->changed = true;
+ elf->changed = true;
+
sec->data->d_buf = relas;
sec->data->d_size = size;
@@ -779,7 +785,44 @@ int elf_rebuild_rela_section(struct section *sec)
return 0;
}
-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_rela(struct elf *elf, struct rela *rela)
+{
+ struct section *sec = rela->sec;
+
+ rela->rela.r_info = GELF_R_INFO(rela->sym->idx, rela->type);
+ rela->rela.r_addend = rela->addend;
+ rela->rela.r_offset = rela->offset;
+
+ if (!gelf_update_rela(sec->data, rela->idx, &rela->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;
@@ -796,6 +839,8 @@ int elf_write(const struct elf *elf)
WARN_ELF("gelf_update_shdr");
return -1;
}
+
+ sec->changed = false;
}
}
@@ -808,6 +853,8 @@ 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 f4fe1d6ea392..7324e772583e 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -64,9 +64,10 @@ struct rela {
GElf_Rela rela;
struct section *sec;
struct symbol *sym;
- unsigned int type;
unsigned long offset;
+ unsigned int type;
int addend;
+ int idx;
bool jump_table_start;
};
@@ -76,6 +77,7 @@ struct elf {
Elf *elf;
GElf_Ehdr ehdr;
int fd;
+ bool changed;
char *name;
struct list_head sections;
DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
@@ -118,7 +120,11 @@ 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_rela_section(struct elf *elf, struct section *base);
void elf_add_rela(struct elf *elf, struct rela *rela);
-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_rela(struct elf *elf, struct rela *rela);
+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);
@@ -130,7 +136,7 @@ struct rela *find_rela_by_dest(const struct elf *elf, struct section *sec, unsig
struct rela *find_rela_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_rela_section(struct section *sec);
+int elf_rebuild_rela_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 c9549988121a..4c37f80eb987 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_rela_section(ip_relasec))
+ if (elf_rebuild_rela_section(file->elf, ip_relasec))
return -1;
return 0;
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-29 13:34:35 +0300