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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-20 10:45:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-20 10:45:15 -0700
commite6023adc5c6af79ac8ac5b17939f58091fa0d870 (patch)
treea6092129571a51fca4e06b7278ff5d6cfb009b7e /tools
parent4b01f5a4c9c4f0c502875c1fb31dcd5d0df86475 (diff)
parentb68b9907069a8d3a65bc16a35360bf8f8603c8fa (diff)
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core fixes from Thomas Gleixner: - A collection of objtool fixes which address recent fallout partially exposed by newer toolchains, clang, BPF and general code changes. - Force USER_DS for user stack traces [ Note: the "objtool fixes" are not all to objtool itself, but for kernel code that triggers objtool warnings. Things like missing function size annotations, or code that confuses the unwinder etc. - Linus] * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) objtool: Support conditional retpolines objtool: Convert insn type to enum objtool: Fix seg fault on bad switch table entry objtool: Support repeated uses of the same C jump table objtool: Refactor jump table code objtool: Refactor sibling call detection logic objtool: Do frame pointer check before dead end check objtool: Change dead_end_function() to return boolean objtool: Warn on zero-length functions objtool: Refactor function alias logic objtool: Track original function across branches objtool: Add mcsafe_handle_tail() to the uaccess safe list bpf: Disable GCC -fgcse optimization for ___bpf_prog_run() x86/uaccess: Remove redundant CLACs in getuser/putuser error paths x86/uaccess: Don't leak AC flag into fentry from mcsafe_handle_tail() x86/uaccess: Remove ELF function annotation from copy_user_handle_tail() x86/head/64: Annotate start_cpu0() as non-callable x86/entry: Fix thunk function ELF sizes x86/kvm: Don't call kvm_spurious_fault() from .fixup x86/kvm: Replace vmx_vmenter()'s call to kvm_spurious_fault() with UD2 ...
Diffstat (limited to 'tools')
-rw-r--r--tools/objtool/arch.h36
-rw-r--r--tools/objtool/arch/x86/decode.c2
-rw-r--r--tools/objtool/check.c333
-rw-r--r--tools/objtool/check.h3
-rw-r--r--tools/objtool/elf.c8
-rw-r--r--tools/objtool/elf.h5
6 files changed, 206 insertions, 181 deletions
diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h
index 580e344db3dd..ced3765c4f44 100644
--- a/tools/objtool/arch.h
+++ b/tools/objtool/arch.h
@@ -11,22 +11,24 @@
#include "elf.h"
#include "cfi.h"
-#define INSN_JUMP_CONDITIONAL 1
-#define INSN_JUMP_UNCONDITIONAL 2
-#define INSN_JUMP_DYNAMIC 3
-#define INSN_CALL 4
-#define INSN_CALL_DYNAMIC 5
-#define INSN_RETURN 6
-#define INSN_CONTEXT_SWITCH 7
-#define INSN_STACK 8
-#define INSN_BUG 9
-#define INSN_NOP 10
-#define INSN_STAC 11
-#define INSN_CLAC 12
-#define INSN_STD 13
-#define INSN_CLD 14
-#define INSN_OTHER 15
-#define INSN_LAST INSN_OTHER
+enum insn_type {
+ INSN_JUMP_CONDITIONAL,
+ INSN_JUMP_UNCONDITIONAL,
+ INSN_JUMP_DYNAMIC,
+ INSN_JUMP_DYNAMIC_CONDITIONAL,
+ INSN_CALL,
+ INSN_CALL_DYNAMIC,
+ INSN_RETURN,
+ INSN_CONTEXT_SWITCH,
+ INSN_STACK,
+ INSN_BUG,
+ INSN_NOP,
+ INSN_STAC,
+ INSN_CLAC,
+ INSN_STD,
+ INSN_CLD,
+ INSN_OTHER,
+};
enum op_dest_type {
OP_DEST_REG,
@@ -68,7 +70,7 @@ void arch_initial_func_cfi_state(struct cfi_state *state);
int arch_decode_instruction(struct elf *elf, struct section *sec,
unsigned long offset, unsigned int maxlen,
- unsigned int *len, unsigned char *type,
+ unsigned int *len, enum insn_type *type,
unsigned long *immediate, struct stack_op *op);
bool arch_callee_saved_reg(unsigned char reg);
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 584568f27a83..0567c47a91b1 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -68,7 +68,7 @@ bool arch_callee_saved_reg(unsigned char reg)
int arch_decode_instruction(struct elf *elf, struct section *sec,
unsigned long offset, unsigned int maxlen,
- unsigned int *len, unsigned char *type,
+ unsigned int *len, enum insn_type *type,
unsigned long *immediate, struct stack_op *op)
{
struct insn insn;
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 172f99195726..5f26620f13f5 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -18,6 +18,8 @@
#define FAKE_JUMP_OFFSET -1
+#define C_JUMP_TABLE_SECTION ".rodata..c_jump_table"
+
struct alternative {
struct list_head list;
struct instruction *insn;
@@ -95,6 +97,20 @@ static struct instruction *next_insn_same_func(struct objtool_file *file,
for (insn = next_insn_same_sec(file, insn); insn; \
insn = next_insn_same_sec(file, insn))
+static bool is_sibling_call(struct instruction *insn)
+{
+ /* An indirect jump is either a sibling call or a jump to a table. */
+ if (insn->type == INSN_JUMP_DYNAMIC)
+ return list_empty(&insn->alts);
+
+ if (insn->type != INSN_JUMP_CONDITIONAL &&
+ insn->type != INSN_JUMP_UNCONDITIONAL)
+ return false;
+
+ /* add_jump_destinations() sets insn->call_dest for sibling calls. */
+ return !!insn->call_dest;
+}
+
/*
* This checks to see if the given function is a "noreturn" function.
*
@@ -103,14 +119,9 @@ static struct instruction *next_insn_same_func(struct objtool_file *file,
*
* For local functions, we have to detect them manually by simply looking for
* the lack of a return instruction.
- *
- * Returns:
- * -1: error
- * 0: no dead end
- * 1: dead end
*/
-static int __dead_end_function(struct objtool_file *file, struct symbol *func,
- int recursion)
+static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
+ int recursion)
{
int i;
struct instruction *insn;
@@ -136,30 +147,33 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
"rewind_stack_do_exit",
};
+ if (!func)
+ return false;
+
if (func->bind == STB_WEAK)
- return 0;
+ return false;
if (func->bind == STB_GLOBAL)
for (i = 0; i < ARRAY_SIZE(global_noreturns); i++)
if (!strcmp(func->name, global_noreturns[i]))
- return 1;
+ return true;
if (!func->len)
- return 0;
+ return false;
insn = find_insn(file, func->sec, func->offset);
if (!insn->func)
- return 0;
+ return false;
func_for_each_insn_all(file, func, insn) {
empty = false;
if (insn->type == INSN_RETURN)
- return 0;
+ return false;
}
if (empty)
- return 0;
+ return false;
/*
* A function can have a sibling call instead of a return. In that
@@ -167,40 +181,31 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
* of the sibling call returns.
*/
func_for_each_insn_all(file, func, insn) {
- if (insn->type == INSN_JUMP_UNCONDITIONAL) {
+ if (is_sibling_call(insn)) {
struct instruction *dest = insn->jump_dest;
if (!dest)
/* sibling call to another file */
- return 0;
-
- if (dest->func && dest->func->pfunc != insn->func->pfunc) {
+ return false;
- /* local sibling call */
- if (recursion == 5) {
- /*
- * Infinite recursion: two functions
- * have sibling calls to each other.
- * This is a very rare case. It means
- * they aren't dead ends.
- */
- return 0;
- }
-
- return __dead_end_function(file, dest->func,
- recursion + 1);
+ /* local sibling call */
+ if (recursion == 5) {
+ /*
+ * Infinite recursion: two functions have
+ * sibling calls to each other. This is a very
+ * rare case. It means they aren't dead ends.
+ */
+ return false;
}
- }
- if (insn->type == INSN_JUMP_DYNAMIC && list_empty(&insn->alts))
- /* sibling call */
- return 0;
+ return __dead_end_function(file, dest->func, recursion+1);
+ }
}
- return 1;
+ return true;
}
-static int dead_end_function(struct objtool_file *file, struct symbol *func)
+static bool dead_end_function(struct objtool_file *file, struct symbol *func)
{
return __dead_end_function(file, func, 0);
}
@@ -262,19 +267,12 @@ static int decode_instructions(struct objtool_file *file)
if (ret)
goto err;
- if (!insn->type || insn->type > INSN_LAST) {
- WARN_FUNC("invalid instruction type %d",
- insn->sec, insn->offset, insn->type);
- ret = -1;
- goto err;
- }
-
hash_add(file->insn_hash, &insn->hash, insn->offset);
list_add_tail(&insn->list, &file->insn_list);
}
list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->type != STT_FUNC)
+ if (func->type != STT_FUNC || func->alias != func)
continue;
if (!find_insn(file, sec, func->offset)) {
@@ -284,8 +282,7 @@ static int decode_instructions(struct objtool_file *file)
}
func_for_each_insn(file, func, insn)
- if (!insn->func)
- insn->func = func;
+ insn->func = func;
}
}
@@ -488,6 +485,7 @@ static const char *uaccess_safe_builtin[] = {
/* misc */
"csum_partial_copy_generic",
"__memcpy_mcsafe",
+ "mcsafe_handle_tail",
"ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
NULL
};
@@ -505,7 +503,7 @@ static void add_uaccess_safe(struct objtool_file *file)
if (!func)
continue;
- func->alias->uaccess_safe = true;
+ func->uaccess_safe = true;
}
}
@@ -577,13 +575,16 @@ static int add_jump_destinations(struct objtool_file *file)
* Retpoline jumps are really dynamic jumps in
* disguise, so convert them accordingly.
*/
- insn->type = INSN_JUMP_DYNAMIC;
+ if (insn->type == INSN_JUMP_UNCONDITIONAL)
+ insn->type = INSN_JUMP_DYNAMIC;
+ else
+ insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL;
+
insn->retpoline_safe = true;
continue;
} else {
- /* sibling call */
+ /* external sibling call */
insn->call_dest = rela->sym;
- insn->jump_dest = NULL;
continue;
}
@@ -623,7 +624,7 @@ static int add_jump_destinations(struct objtool_file *file)
* However this code can't completely replace the
* read_symbols() code because this doesn't detect the
* case where the parent function's only reference to a
- * subfunction is through a switch table.
+ * subfunction is through a jump table.
*/
if (!strstr(insn->func->name, ".cold.") &&
strstr(insn->jump_dest->func->name, ".cold.")) {
@@ -633,9 +634,8 @@ static int add_jump_destinations(struct objtool_file *file)
} else if (insn->jump_dest->func->pfunc != insn->func->pfunc &&
insn->jump_dest->offset == insn->jump_dest->func->offset) {
- /* sibling class */
+ /* internal sibling call */
insn->call_dest = insn->jump_dest->func;
- insn->jump_dest = NULL;
}
}
}
@@ -896,20 +896,26 @@ out:
return ret;
}
-static int add_switch_table(struct objtool_file *file, struct instruction *insn,
- struct rela *table, struct rela *next_table)
+static int add_jump_table(struct objtool_file *file, struct instruction *insn,
+ struct rela *table)
{
struct rela *rela = table;
- struct instruction *alt_insn;
+ struct instruction *dest_insn;
struct alternative *alt;
struct symbol *pfunc = insn->func->pfunc;
unsigned int prev_offset = 0;
- list_for_each_entry_from(rela, &table->rela_sec->rela_list, list) {
- if (rela == next_table)
+ /*
+ * Each @rela is a switch table relocation which points to the target
+ * instruction.
+ */
+ list_for_each_entry_from(rela, &table->sec->rela_list, list) {
+
+ /* Check for the end of the table: */
+ if (rela != table && rela->jump_table_start)
break;
- /* Make sure the switch table entries are consecutive: */
+ /* Make sure the table entries are consecutive: */
if (prev_offset && rela->offset != prev_offset + 8)
break;
@@ -918,12 +924,12 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,
rela->addend == pfunc->offset)
break;
- alt_insn = find_insn(file, rela->sym->sec, rela->addend);
- if (!alt_insn)
+ dest_insn = find_insn(file, rela->sym->sec, rela->addend);
+ if (!dest_insn)
break;
- /* Make sure the jmp dest is in the function or subfunction: */
- if (alt_insn->func->pfunc != pfunc)
+ /* Make sure the destination is in the same function: */
+ if (!dest_insn->func || dest_insn->func->pfunc != pfunc)
break;
alt = malloc(sizeof(*alt));
@@ -932,7 +938,7 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,
return -1;
}
- alt->insn = alt_insn;
+ alt->insn = dest_insn;
list_add_tail(&alt->list, &insn->alts);
prev_offset = rela->offset;
}
@@ -947,7 +953,7 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,
}
/*
- * find_switch_table() - Given a dynamic jump, find the switch jump table in
+ * find_jump_table() - Given a dynamic jump, find the switch jump table in
* .rodata associated with it.
*
* There are 3 basic patterns:
@@ -989,13 +995,13 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,
*
* NOTE: RETPOLINE made it harder still to decode dynamic jumps.
*/
-static struct rela *find_switch_table(struct objtool_file *file,
+static struct rela *find_jump_table(struct objtool_file *file,
struct symbol *func,
struct instruction *insn)
{
- struct rela *text_rela, *rodata_rela;
+ struct rela *text_rela, *table_rela;
struct instruction *orig_insn = insn;
- struct section *rodata_sec;
+ struct section *table_sec;
unsigned long table_offset;
/*
@@ -1028,42 +1034,52 @@ static struct rela *find_switch_table(struct objtool_file *file,
continue;
table_offset = text_rela->addend;
- rodata_sec = text_rela->sym->sec;
+ table_sec = text_rela->sym->sec;
if (text_rela->type == R_X86_64_PC32)
table_offset += 4;
/*
* Make sure the .rodata address isn't associated with a
- * symbol. gcc jump tables are anonymous data.
+ * symbol. GCC jump tables are anonymous data.
+ *
+ * Also support C jump tables which are in the same format as
+ * switch jump tables. For objtool to recognize them, they
+ * need to be placed in the C_JUMP_TABLE_SECTION section. They
+ * have symbols associated with them.
*/
- if (find_symbol_containing(rodata_sec, table_offset))
+ if (find_symbol_containing(table_sec, table_offset) &&
+ strcmp(table_sec->name, C_JUMP_TABLE_SECTION))
continue;
- rodata_rela = find_rela_by_dest(rodata_sec, table_offset);
- if (rodata_rela) {
- /*
- * Use of RIP-relative switch jumps is quite rare, and
- * indicates a rare GCC quirk/bug which can leave dead
- * code behind.
- */
- if (text_rela->type == R_X86_64_PC32)
- file->ignore_unreachables = true;
+ /* Each table entry has a rela associated with it. */
+ table_rela = find_rela_by_dest(table_sec, table_offset);
+ if (!table_rela)
+ continue;
- return rodata_rela;
- }
+ /*
+ * Use of RIP-relative switch jumps is quite rare, and
+ * indicates a rare GCC quirk/bug which can leave dead code
+ * behind.
+ */
+ if (text_rela->type == R_X86_64_PC32)
+ file->ignore_unreachables = true;
+
+ return table_rela;
}
return NULL;
}
-
-static int add_func_switch_tables(struct objtool_file *file,
- struct symbol *func)
+/*
+ * First pass: Mark the head of each jump table so that in the next pass,
+ * we know when a given jump table ends and the next one starts.
+ */
+static void mark_func_jump_tables(struct objtool_file *file,
+ struct symbol *func)
{
- struct instruction *insn, *last = NULL, *prev_jump = NULL;
- struct rela *rela, *prev_rela = NULL;
- int ret;
+ struct instruction *insn, *last = NULL;
+ struct rela *rela;
func_for_each_insn_all(file, func, insn) {
if (!last)
@@ -1071,7 +1087,7 @@ static int add_func_switch_tables(struct objtool_file *file,
/*
* Store back-pointers for unconditional forward jumps such
- * that find_switch_table() can back-track using those and
+ * that find_jump_table() can back-track using those and
* avoid some potentially confusing code.
*/
if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest &&
@@ -1086,27 +1102,25 @@ static int add_func_switch_tables(struct objtool_file *file,
if (insn->type != INSN_JUMP_DYNAMIC)
continue;
- rela = find_switch_table(file, func, insn);
- if (!rela)
- continue;
-
- /*
- * We found a switch table, but we don't know yet how big it
- * is. Don't add it until we reach the end of the function or
- * the beginning of another switch table in the same function.
- */
- if (prev_jump) {
- ret = add_switch_table(file, prev_jump, prev_rela, rela);
- if (ret)
- return ret;
+ rela = find_jump_table(file, func, insn);
+ if (rela) {
+ rela->jump_table_start = true;
+ insn->jump_table = rela;
}
-
- prev_jump = insn;
- prev_rela = rela;
}
+}
+
+static int add_func_jump_tables(struct objtool_file *file,
+ struct symbol *func)
+{
+ struct instruction *insn;
+ int ret;
- if (prev_jump) {
- ret = add_switch_table(file, prev_jump, prev_rela, NULL);
+ func_for_each_insn_all(file, func, insn) {
+ if (!insn->jump_table)
+ continue;
+
+ ret = add_jump_table(file, insn, insn->jump_table);
if (ret)
return ret;
}
@@ -1119,7 +1133,7 @@ static int add_func_switch_tables(struct objtool_file *file,
* section which contains a list of addresses within the function to jump to.
* This finds these jump tables and adds them to the insn->alts lists.
*/
-static int add_switch_table_alts(struct objtool_file *file)
+static int add_jump_table_alts(struct objtool_file *file)
{
struct section *sec;
struct symbol *func;
@@ -1133,7 +1147,8 @@ static int add_switch_table_alts(struct objtool_file *file)
if (func->type != STT_FUNC)
continue;
- ret = add_func_switch_tables(file, func);
+ mark_func_jump_tables(file, func);
+ ret = add_func_jump_tables(file, func);
if (ret)
return ret;
}
@@ -1277,13 +1292,18 @@ static void mark_rodata(struct objtool_file *file)
bool found = false;
/*
- * This searches for the .rodata section or multiple .rodata.func_name
- * sections if -fdata-sections is being used. The .str.1.1 and .str.1.8
- * rodata sections are ignored as they don't contain jump tables.
+ * Search for the following rodata sections, each of which can
+ * potentially contain jump tables:
+ *
+ * - .rodata: can contain GCC switch tables
+ * - .rodata.<func>: same, if -fdata-sections is being used
+ * - .rodata..c_jump_table: contains C annotated jump tables
+ *
+ * .rodata.str1.* sections are ignored; they don't contain jump tables.
*/
for_each_sec(file, sec) {
- if (!strncmp(sec->name, ".rodata", 7) &&
- !strstr(sec->name, ".str1.")) {
+ if ((!strncmp(sec->name, ".rodata", 7) && !strstr(sec->name, ".str1.")) ||
+ !strcmp(sec->name, C_JUMP_TABLE_SECTION)) {
sec->rodata = true;
found = true;
}
@@ -1325,7 +1345,7 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
- ret = add_switch_table_alts(file);
+ ret = add_jump_table_alts(file);
if (ret)
return ret;
@@ -1873,12 +1893,12 @@ static bool insn_state_match(struct instruction *insn, struct insn_state *state)
static inline bool func_uaccess_safe(struct symbol *func)
{
if (func)
- return func->alias->uaccess_safe;
+ return func->uaccess_safe;
return false;
}
-static inline const char *insn_dest_name(struct instruction *insn)
+static inline const char *call_dest_name(struct instruction *insn)
{
if (insn->call_dest)
return insn->call_dest->name;
@@ -1890,13 +1910,13 @@ static int validate_call(struct instruction *insn, struct insn_state *state)
{
if (state->uaccess && !func_uaccess_safe(insn->call_dest)) {
WARN_FUNC("call to %s() with UACCESS enabled",
- insn->sec, insn->offset, insn_dest_name(insn));
+ insn->sec, insn->offset, call_dest_name(insn));
return 1;
}
if (state->df) {
WARN_FUNC("call to %s() with DF set",
- insn->sec, insn->offset, insn_dest_name(insn));
+ insn->sec, insn->offset, call_dest_name(insn));
return 1;
}
@@ -1920,13 +1940,12 @@ static int validate_sibling_call(struct instruction *insn, struct insn_state *st
* each instruction and validate all the rules described in
* tools/objtool/Documentation/stack-validation.txt.
*/
-static int validate_branch(struct objtool_file *file, struct instruction *first,
- struct insn_state state)
+static int validate_branch(struct objtool_file *file, struct symbol *func,
+ struct instruction *first, struct insn_state state)
{
struct alternative *alt;
struct instruction *insn, *next_insn;
struct section *sec;
- struct symbol *func = NULL;
int ret;
insn = first;
@@ -1947,9 +1966,6 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
return 1;
}
- if (insn->func)
- func = insn->func->pfunc;
-
if (func && insn->ignore) {
WARN_FUNC("BUG: why am I validating an ignored function?",
sec, insn->offset);
@@ -1971,7 +1987,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
i = insn;
save_insn = NULL;
- func_for_each_insn_continue_reverse(file, insn->func, i) {
+ func_for_each_insn_continue_reverse(file, func, i) {
if (i->save) {
save_insn = i;
break;
@@ -2017,7 +2033,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
if (alt->skip_orig)
skip_orig = true;
- ret = validate_branch(file, alt->insn, state);
+ ret = validate_branch(file, func, alt->insn, state);
if (ret) {
if (backtrace)
BT_FUNC("(alt)", insn);
@@ -2055,7 +2071,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
if (state.bp_scratch) {
WARN("%s uses BP as a scratch register",
- insn->func->name);
+ func->name);
return 1;
}
@@ -2067,36 +2083,28 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
if (ret)
return ret;
- if (insn->type == INSN_CALL) {
- if (is_fentry_call(insn))
- break;
-
- ret = dead_end_function(file, insn->call_dest);
- if (ret == 1)
- return 0;
- if (ret == -1)
- return 1;
- }
-
- if (!no_fp && func && !has_valid_stack_frame(&state)) {
+ if (!no_fp && func && !is_fentry_call(insn) &&
+ !has_valid_stack_frame(&state)) {
WARN_FUNC("call without frame pointer save/setup",
sec, insn->offset);
return 1;
}
+
+ if (dead_end_function(file, insn->call_dest))
+ return 0;
+
break;
case INSN_JUMP_CONDITIONAL:
case INSN_JUMP_UNCONDITIONAL:
- if (func && !insn->jump_dest) {
+ if (func && is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
if (ret)
return ret;
- } else if (insn->jump_dest &&
- (!func || !insn->jump_dest->func ||
- insn->jump_dest->func->pfunc == func)) {
- ret = validate_branch(file, insn->jump_dest,
- state);
+ } else if (insn->jump_dest) {
+ ret = validate_branch(file, func,
+ insn->jump_dest, state);
if (ret) {
if (backtrace)
BT_FUNC("(branch)", insn);
@@ -2110,13 +2118,17 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
break;
case INSN_JUMP_DYNAMIC:
- if (func && list_empty(&insn->alts)) {
+ case INSN_JUMP_DYNAMIC_CONDITIONAL:
+ if (func && is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
if (ret)
return ret;
}
- return 0;
+ if (insn->type == INSN_JUMP_DYNAMIC)
+ return 0;
+
+ break;
case INSN_CONTEXT_SWITCH:
if (func && (!next_insn || !next_insn->hint)) {
@@ -2162,7 +2174,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
break;
case INSN_CLAC:
- if (!state.uaccess && insn->func) {
+ if (!state.uaccess && func) {
WARN_FUNC("redundant UACCESS disable", sec, insn->offset);
return 1;
}
@@ -2183,7 +2195,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
break;
case INSN_CLD:
- if (!state.df && insn->func)
+ if (!state.df && func)
WARN_FUNC("redundant CLD", sec, insn->offset);
state.df = false;
@@ -2222,7 +2234,7 @@ static int validate_unwind_hints(struct objtool_file *file)
for_each_insn(file, insn) {
if (insn->hint && !insn->visited) {
- ret = validate_branch(file, insn, state);
+ ret = validate_branch(file, insn->func, insn, state);
if (ret && backtrace)
BT_FUNC("<=== (hint)", insn);
warnings += ret;
@@ -2345,16 +2357,25 @@ static int validate_functions(struct objtool_file *file)
for_each_sec(file, sec) {
list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->type != STT_FUNC || func->pfunc != func)
+ if (func->type != STT_FUNC)
+ continue;
+
+ if (!func->len) {
+ WARN("%s() is missing an ELF size annotation",
+ func->name);
+ warnings++;
+ }
+
+ if (func->pfunc != func || func->alias != func)
continue;
insn = find_insn(file, sec, func->offset);
- if (!insn || insn->ignore)
+ if (!insn || insn->ignore || insn->visited)
continue;
- state.uaccess = func->alias->uaccess_safe;
+ state.uaccess = func->uaccess_safe;
- ret = validate_branch(file, insn, state);
+ ret = validate_branch(file, func, insn, state);
if (ret && backtrace)
BT_FUNC("<=== (func)", insn);
warnings += ret;
@@ -2407,7 +2428,7 @@ int check(const char *_objname, bool orc)
objname = _objname;
- file.elf = elf_open(objname, orc ? O_RDWR : O_RDONLY);
+ file.elf = elf_read(objname, orc ? O_RDWR : O_RDONLY);
if (!file.elf)
return 1;
diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index cb60b9acf5cf..b881fafcf55d 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -31,13 +31,14 @@ struct instruction {
struct section *sec;
unsigned long offset;
unsigned int len;
- unsigned char type;
+ enum insn_type type;
unsigned long immediate;
bool alt_group, visited, dead_end, ignore, hint, save, restore, ignore_alts;
bool retpoline_safe;
struct symbol *call_dest;
struct instruction *jump_dest;
struct instruction *first_jump_src;
+ struct rela *jump_table;
struct list_head alts;
struct symbol *func;
struct stack_op stack_op;
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index e99e1be19ad9..edba4745f25a 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -278,7 +278,7 @@ static int read_symbols(struct elf *elf)
}
if (sym->offset == s->offset) {
- if (sym->len == s->len && alias == sym)
+ if (sym->len && sym->len == s->len && alias == sym)
alias = s;
if (sym->len >= s->len) {
@@ -385,7 +385,7 @@ static int read_relas(struct elf *elf)
rela->offset = rela->rela.r_offset;
symndx = GELF_R_SYM(rela->rela.r_info);
rela->sym = find_symbol_by_index(elf, symndx);
- rela->rela_sec = sec;
+ rela->sec = sec;
if (!rela->sym) {
WARN("can't find rela entry symbol %d for %s",
symndx, sec->name);
@@ -401,7 +401,7 @@ static int read_relas(struct elf *elf)
return 0;
}
-struct elf *elf_open(const char *name, int flags)
+struct elf *elf_read(const char *name, int flags)
{
struct elf *elf;
Elf_Cmd cmd;
@@ -463,7 +463,7 @@ struct section *elf_create_section(struct elf *elf, const char *name,
{
struct section *sec, *shstrtab;
size_t size = entsize * nr;
- struct Elf_Scn *s;
+ Elf_Scn *s;
Elf_Data *data;
sec = malloc(sizeof(*sec));
diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index e44ca5d51871..44150204db4d 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -57,11 +57,12 @@ struct rela {
struct list_head list;
struct hlist_node hash;
GElf_Rela rela;
- struct section *rela_sec;
+ struct section *sec;
struct symbol *sym;
unsigned int type;
unsigned long offset;
int addend;
+ bool jump_table_start;
};
struct elf {
@@ -74,7 +75,7 @@ struct elf {
};
-struct elf *elf_open(const char *name, int flags);
+struct elf *elf_read(const char *name, int flags);
struct section *find_section_by_name(struct elf *elf, const char *name);
struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
struct symbol *find_symbol_by_name(struct elf *elf, const char *name);