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-rw-r--r--tools/objtool/check.c674
1 files changed, 310 insertions, 364 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 548ec3cd7c00..ce973d9d8e6d 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -20,6 +20,7 @@
#include <linux/hashtable.h>
#include <linux/kernel.h>
#include <linux/static_call_types.h>
+#include <linux/string.h>
struct alternative {
struct alternative *next;
@@ -149,6 +150,15 @@ static inline struct reloc *insn_jump_table(struct instruction *insn)
return NULL;
}
+static inline unsigned long insn_jump_table_size(struct instruction *insn)
+{
+ if (insn->type == INSN_JUMP_DYNAMIC ||
+ insn->type == INSN_CALL_DYNAMIC)
+ return insn->_jump_table_size;
+
+ return 0;
+}
+
static bool is_jump_table_jump(struct instruction *insn)
{
struct alt_group *alt_group = insn->alt_group;
@@ -177,6 +187,53 @@ static bool is_sibling_call(struct instruction *insn)
}
/*
+ * Checks if a string ends with another.
+ */
+static bool str_ends_with(const char *s, const char *sub)
+{
+ const int slen = strlen(s);
+ const int sublen = strlen(sub);
+
+ if (sublen > slen)
+ return 0;
+
+ return !memcmp(s + slen - sublen, sub, sublen);
+}
+
+/*
+ * Checks if a function is a Rust "noreturn" one.
+ */
+static bool is_rust_noreturn(const struct symbol *func)
+{
+ /*
+ * If it does not start with "_R", then it is not a Rust symbol.
+ */
+ if (strncmp(func->name, "_R", 2))
+ return false;
+
+ /*
+ * These are just heuristics -- we do not control the precise symbol
+ * name, due to the crate disambiguators (which depend on the compiler)
+ * as well as changes to the source code itself between versions (since
+ * these come from the Rust standard library).
+ */
+ return str_ends_with(func->name, "_4core5sliceSp15copy_from_slice17len_mismatch_fail") ||
+ str_ends_with(func->name, "_4core6option13unwrap_failed") ||
+ str_ends_with(func->name, "_4core6result13unwrap_failed") ||
+ str_ends_with(func->name, "_4core9panicking5panic") ||
+ str_ends_with(func->name, "_4core9panicking9panic_fmt") ||
+ str_ends_with(func->name, "_4core9panicking14panic_explicit") ||
+ str_ends_with(func->name, "_4core9panicking14panic_nounwind") ||
+ str_ends_with(func->name, "_4core9panicking18panic_bounds_check") ||
+ str_ends_with(func->name, "_4core9panicking19assert_failed_inner") ||
+ str_ends_with(func->name, "_4core9panicking36panic_misaligned_pointer_dereference") ||
+ strstr(func->name, "_4core9panicking13assert_failed") ||
+ strstr(func->name, "_4core9panicking11panic_const24panic_const_") ||
+ (strstr(func->name, "_4core5slice5index24slice_") &&
+ str_ends_with(func->name, "_fail"));
+}
+
+/*
* This checks to see if the given function is a "noreturn" function.
*
* For global functions which are outside the scope of this object file, we
@@ -201,10 +258,14 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
if (!func)
return false;
- if (func->bind == STB_GLOBAL || func->bind == STB_WEAK)
+ if (func->bind == STB_GLOBAL || func->bind == STB_WEAK) {
+ if (is_rust_noreturn(func))
+ return true;
+
for (i = 0; i < ARRAY_SIZE(global_noreturns); i++)
if (!strcmp(func->name, global_noreturns[i]))
return true;
+ }
if (func->bind == STB_WEAK)
return false;
@@ -563,106 +624,6 @@ static int init_pv_ops(struct objtool_file *file)
return 0;
}
-static struct instruction *find_last_insn(struct objtool_file *file,
- struct section *sec)
-{
- struct instruction *insn = NULL;
- unsigned int offset;
- unsigned int end = (sec->sh.sh_size > 10) ? sec->sh.sh_size - 10 : 0;
-
- for (offset = sec->sh.sh_size - 1; offset >= end && !insn; offset--)
- insn = find_insn(file, sec, offset);
-
- return insn;
-}
-
-/*
- * Mark "ud2" instructions and manually annotated dead ends.
- */
-static int add_dead_ends(struct objtool_file *file)
-{
- struct section *rsec;
- struct reloc *reloc;
- struct instruction *insn;
- s64 addend;
-
- /*
- * Check for manually annotated dead ends.
- */
- rsec = find_section_by_name(file->elf, ".rela.discard.unreachable");
- if (!rsec)
- goto reachable;
-
- for_each_reloc(rsec, reloc) {
-
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
-
- addend = reloc_addend(reloc);
-
- insn = find_insn(file, reloc->sym->sec, addend);
- if (insn)
- insn = prev_insn_same_sec(file, insn);
- else if (addend == reloc->sym->sec->sh.sh_size) {
- insn = find_last_insn(file, reloc->sym->sec);
- if (!insn) {
- WARN("can't find unreachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, addend);
- return -1;
- }
- } else {
- WARN("can't find unreachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, addend);
- return -1;
- }
-
- insn->dead_end = true;
- }
-
-reachable:
- /*
- * These manually annotated reachable checks are needed for GCC 4.4,
- * where the Linux unreachable() macro isn't supported. In that case
- * GCC doesn't know the "ud2" is fatal, so it generates code as if it's
- * not a dead end.
- */
- rsec = find_section_by_name(file->elf, ".rela.discard.reachable");
- if (!rsec)
- return 0;
-
- for_each_reloc(rsec, reloc) {
-
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
-
- addend = reloc_addend(reloc);
-
- insn = find_insn(file, reloc->sym->sec, addend);
- if (insn)
- insn = prev_insn_same_sec(file, insn);
- else if (addend == reloc->sym->sec->sh.sh_size) {
- insn = find_last_insn(file, reloc->sym->sec);
- if (!insn) {
- WARN("can't find reachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, addend);
- return -1;
- }
- } else {
- WARN("can't find reachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, addend);
- return -1;
- }
-
- insn->dead_end = false;
- }
-
- return 0;
-}
-
static int create_static_call_sections(struct objtool_file *file)
{
struct static_call_site *site;
@@ -1199,6 +1160,8 @@ static const char *uaccess_safe_builtin[] = {
"__sanitizer_cov_trace_switch",
/* KMSAN */
"kmsan_copy_to_user",
+ "kmsan_disable_current",
+ "kmsan_enable_current",
"kmsan_report",
"kmsan_unpoison_entry_regs",
"kmsan_unpoison_memory",
@@ -1255,40 +1218,6 @@ static void add_uaccess_safe(struct objtool_file *file)
}
/*
- * FIXME: For now, just ignore any alternatives which add retpolines. This is
- * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline.
- * But it at least allows objtool to understand the control flow *around* the
- * retpoline.
- */
-static int add_ignore_alternatives(struct objtool_file *file)
-{
- struct section *rsec;
- struct reloc *reloc;
- struct instruction *insn;
-
- rsec = find_section_by_name(file->elf, ".rela.discard.ignore_alts");
- if (!rsec)
- return 0;
-
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
-
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.ignore_alts entry");
- return -1;
- }
-
- insn->ignore_alts = true;
- }
-
- return 0;
-}
-
-/*
* Symbols that replace INSN_CALL_DYNAMIC, every (tail) call to such a symbol
* will be added to the .retpoline_sites section.
*/
@@ -2018,6 +1947,7 @@ out:
static int add_jump_table(struct objtool_file *file, struct instruction *insn,
struct reloc *next_table)
{
+ unsigned long table_size = insn_jump_table_size(insn);
struct symbol *pfunc = insn_func(insn)->pfunc;
struct reloc *table = insn_jump_table(insn);
struct instruction *dest_insn;
@@ -2032,6 +1962,8 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
for_each_reloc_from(table->sec, reloc) {
/* Check for the end of the table: */
+ if (table_size && reloc_offset(reloc) - reloc_offset(table) >= table_size)
+ break;
if (reloc != table && reloc == next_table)
break;
@@ -2044,6 +1976,14 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
reloc_addend(reloc) == pfunc->offset)
break;
+ /*
+ * Clang sometimes leaves dangling unused jump table entries
+ * which point to the end of the function. Ignore them.
+ */
+ if (reloc->sym->sec == pfunc->sec &&
+ reloc_addend(reloc) == pfunc->offset + pfunc->len)
+ goto next;
+
dest_insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!dest_insn)
break;
@@ -2061,6 +2001,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
alt->insn = dest_insn;
alt->next = insn->alts;
insn->alts = alt;
+next:
prev_offset = reloc_offset(reloc);
}
@@ -2076,12 +2017,12 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
* find_jump_table() - Given a dynamic jump, find the switch jump table
* associated with it.
*/
-static struct reloc *find_jump_table(struct objtool_file *file,
- struct symbol *func,
- struct instruction *insn)
+static void find_jump_table(struct objtool_file *file, struct symbol *func,
+ struct instruction *insn)
{
struct reloc *table_reloc;
struct instruction *dest_insn, *orig_insn = insn;
+ unsigned long table_size;
/*
* Backward search using the @first_jump_src links, these help avoid
@@ -2102,17 +2043,17 @@ static struct reloc *find_jump_table(struct objtool_file *file,
insn->jump_dest->offset > orig_insn->offset))
break;
- table_reloc = arch_find_switch_table(file, insn);
+ table_reloc = arch_find_switch_table(file, insn, &table_size);
if (!table_reloc)
continue;
dest_insn = find_insn(file, table_reloc->sym->sec, reloc_addend(table_reloc));
if (!dest_insn || !insn_func(dest_insn) || insn_func(dest_insn)->pfunc != func)
continue;
- return table_reloc;
+ orig_insn->_jump_table = table_reloc;
+ orig_insn->_jump_table_size = table_size;
+ break;
}
-
- return NULL;
}
/*
@@ -2123,7 +2064,6 @@ static void mark_func_jump_tables(struct objtool_file *file,
struct symbol *func)
{
struct instruction *insn, *last = NULL;
- struct reloc *reloc;
func_for_each_insn(file, func, insn) {
if (!last)
@@ -2146,9 +2086,7 @@ static void mark_func_jump_tables(struct objtool_file *file,
if (insn->type != INSN_JUMP_DYNAMIC)
continue;
- reloc = find_jump_table(file, func, insn);
- if (reloc)
- insn->_jump_table = reloc;
+ find_jump_table(file, func, insn);
}
}
@@ -2224,6 +2162,7 @@ static int read_unwind_hints(struct objtool_file *file)
struct unwind_hint *hint;
struct instruction *insn;
struct reloc *reloc;
+ unsigned long offset;
int i;
sec = find_section_by_name(file->elf, ".discard.unwind_hints");
@@ -2251,7 +2190,16 @@ static int read_unwind_hints(struct objtool_file *file)
return -1;
}
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
+ if (reloc->sym->type == STT_SECTION) {
+ offset = reloc_addend(reloc);
+ } else if (reloc->sym->local_label) {
+ offset = reloc->sym->offset;
+ } else {
+ WARN("unexpected relocation symbol type in %s", sec->rsec->name);
+ return -1;
+ }
+
+ insn = find_insn(file, reloc->sym->sec, offset);
if (!insn) {
WARN("can't find insn for unwind_hints[%d]", i);
return -1;
@@ -2308,185 +2256,147 @@ static int read_unwind_hints(struct objtool_file *file)
return 0;
}
-static int read_noendbr_hints(struct objtool_file *file)
+static int read_annotate(struct objtool_file *file,
+ int (*func)(struct objtool_file *file, int type, struct instruction *insn))
{
+ struct section *sec;
struct instruction *insn;
- struct section *rsec;
struct reloc *reloc;
+ uint64_t offset;
+ int type, ret;
- rsec = find_section_by_name(file->elf, ".rela.discard.noendbr");
- if (!rsec)
+ sec = find_section_by_name(file->elf, ".discard.annotate_insn");
+ if (!sec)
return 0;
- for_each_reloc(rsec, reloc) {
- insn = find_insn(file, reloc->sym->sec,
- reloc->sym->offset + reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.noendbr entry");
- return -1;
- }
+ if (!sec->rsec)
+ return 0;
- insn->noendbr = 1;
+ if (sec->sh.sh_entsize != 8) {
+ static bool warned = false;
+ if (!warned && opts.verbose) {
+ WARN("%s: dodgy linker, sh_entsize != 8", sec->name);
+ warned = true;
+ }
+ sec->sh.sh_entsize = 8;
}
- return 0;
-}
-
-static int read_retpoline_hints(struct objtool_file *file)
-{
- struct section *rsec;
- struct instruction *insn;
- struct reloc *reloc;
-
- rsec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");
- if (!rsec)
- return 0;
+ for_each_reloc(sec->rsec, reloc) {
+ type = *(u32 *)(sec->data->d_buf + (reloc_idx(reloc) * sec->sh.sh_entsize) + 4);
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
+ offset = reloc->sym->offset + reloc_addend(reloc);
+ insn = find_insn(file, reloc->sym->sec, offset);
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!insn) {
- WARN("bad .discard.retpoline_safe entry");
- return -1;
- }
-
- if (insn->type != INSN_JUMP_DYNAMIC &&
- insn->type != INSN_CALL_DYNAMIC &&
- insn->type != INSN_RETURN &&
- insn->type != INSN_NOP) {
- WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
+ WARN("bad .discard.annotate_insn entry: %d of type %d", reloc_idx(reloc), type);
return -1;
}
- insn->retpoline_safe = true;
+ ret = func(file, type, insn);
+ if (ret < 0)
+ return ret;
}
return 0;
}
-static int read_instr_hints(struct objtool_file *file)
+static int __annotate_early(struct objtool_file *file, int type, struct instruction *insn)
{
- struct section *rsec;
- struct instruction *insn;
- struct reloc *reloc;
+ switch (type) {
+ case ANNOTYPE_IGNORE_ALTS:
+ insn->ignore_alts = true;
+ break;
- rsec = find_section_by_name(file->elf, ".rela.discard.instr_end");
- if (!rsec)
- return 0;
+ /*
+ * Must be before read_unwind_hints() since that needs insn->noendbr.
+ */
+ case ANNOTYPE_NOENDBR:
+ insn->noendbr = 1;
+ break;
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
+ default:
+ break;
+ }
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.instr_end entry");
- return -1;
- }
+ return 0;
+}
- insn->instr--;
- }
+static int __annotate_ifc(struct objtool_file *file, int type, struct instruction *insn)
+{
+ unsigned long dest_off;
- rsec = find_section_by_name(file->elf, ".rela.discard.instr_begin");
- if (!rsec)
+ if (type != ANNOTYPE_INTRA_FUNCTION_CALL)
return 0;
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
+ if (insn->type != INSN_CALL) {
+ WARN_INSN(insn, "intra_function_call not a direct call");
+ return -1;
+ }
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.instr_begin entry");
- return -1;
- }
+ /*
+ * Treat intra-function CALLs as JMPs, but with a stack_op.
+ * See add_call_destinations(), which strips stack_ops from
+ * normal CALLs.
+ */
+ insn->type = INSN_JUMP_UNCONDITIONAL;
- insn->instr++;
+ dest_off = arch_jump_destination(insn);
+ insn->jump_dest = find_insn(file, insn->sec, dest_off);
+ if (!insn->jump_dest) {
+ WARN_INSN(insn, "can't find call dest at %s+0x%lx",
+ insn->sec->name, dest_off);
+ return -1;
}
return 0;
}
-static int read_validate_unret_hints(struct objtool_file *file)
+static int __annotate_late(struct objtool_file *file, int type, struct instruction *insn)
{
- struct section *rsec;
- struct instruction *insn;
- struct reloc *reloc;
-
- rsec = find_section_by_name(file->elf, ".rela.discard.validate_unret");
- if (!rsec)
- return 0;
-
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
+ switch (type) {
+ case ANNOTYPE_NOENDBR:
+ /* early */
+ break;
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.instr_end entry");
+ case ANNOTYPE_RETPOLINE_SAFE:
+ if (insn->type != INSN_JUMP_DYNAMIC &&
+ insn->type != INSN_CALL_DYNAMIC &&
+ insn->type != INSN_RETURN &&
+ insn->type != INSN_NOP) {
+ WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
return -1;
}
- insn->unret = 1;
- }
-
- return 0;
-}
-
-static int read_intra_function_calls(struct objtool_file *file)
-{
- struct instruction *insn;
- struct section *rsec;
- struct reloc *reloc;
+ insn->retpoline_safe = true;
+ break;
- rsec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls");
- if (!rsec)
- return 0;
+ case ANNOTYPE_INSTR_BEGIN:
+ insn->instr++;
+ break;
- for_each_reloc(rsec, reloc) {
- unsigned long dest_off;
+ case ANNOTYPE_INSTR_END:
+ insn->instr--;
+ break;
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s",
- rsec->name);
- return -1;
- }
+ case ANNOTYPE_UNRET_BEGIN:
+ insn->unret = 1;
+ break;
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.intra_function_call entry");
- return -1;
- }
+ case ANNOTYPE_IGNORE_ALTS:
+ /* early */
+ break;
- if (insn->type != INSN_CALL) {
- WARN_INSN(insn, "intra_function_call not a direct call");
- return -1;
- }
+ case ANNOTYPE_INTRA_FUNCTION_CALL:
+ /* ifc */
+ break;
- /*
- * Treat intra-function CALLs as JMPs, but with a stack_op.
- * See add_call_destinations(), which strips stack_ops from
- * normal CALLs.
- */
- insn->type = INSN_JUMP_UNCONDITIONAL;
+ case ANNOTYPE_REACHABLE:
+ insn->dead_end = false;
+ break;
- dest_off = arch_jump_destination(insn);
- insn->jump_dest = find_insn(file, insn->sec, dest_off);
- if (!insn->jump_dest) {
- WARN_INSN(insn, "can't find call dest at %s+0x%lx",
- insn->sec->name, dest_off);
- return -1;
- }
+ default:
+ WARN_INSN(insn, "Unknown annotation type: %d", type);
+ break;
}
return 0;
@@ -2522,6 +2432,9 @@ static int classify_symbols(struct objtool_file *file)
struct symbol *func;
for_each_sym(file, func) {
+ if (func->type == STT_NOTYPE && strstarts(func->name, ".L"))
+ func->local_label = true;
+
if (func->bind != STB_GLOBAL)
continue;
@@ -2559,13 +2472,14 @@ static void mark_rodata(struct objtool_file *file)
*
* - .rodata: can contain GCC switch tables
* - .rodata.<func>: same, if -fdata-sections is being used
- * - .rodata..c_jump_table: contains C annotated jump tables
+ * - .data.rel.ro.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.")) ||
+ !strncmp(sec->name, ".data.rel.ro", 12)) {
sec->rodata = true;
found = true;
}
@@ -2598,14 +2512,7 @@ static int decode_sections(struct objtool_file *file)
add_ignores(file);
add_uaccess_safe(file);
- ret = add_ignore_alternatives(file);
- if (ret)
- return ret;
-
- /*
- * Must be before read_unwind_hints() since that needs insn->noendbr.
- */
- ret = read_noendbr_hints(file);
+ ret = read_annotate(file, __annotate_early);
if (ret)
return ret;
@@ -2627,7 +2534,7 @@ static int decode_sections(struct objtool_file *file)
* Must be before add_call_destination(); it changes INSN_CALL to
* INSN_JUMP.
*/
- ret = read_intra_function_calls(file);
+ ret = read_annotate(file, __annotate_ifc);
if (ret)
return ret;
@@ -2635,14 +2542,6 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
- /*
- * Must be after add_call_destinations() such that it can override
- * dead_end_function() marks.
- */
- ret = add_dead_ends(file);
- if (ret)
- return ret;
-
ret = add_jump_table_alts(file);
if (ret)
return ret;
@@ -2651,15 +2550,11 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
- ret = read_retpoline_hints(file);
- if (ret)
- return ret;
-
- ret = read_instr_hints(file);
- if (ret)
- return ret;
-
- ret = read_validate_unret_hints(file);
+ /*
+ * Must be after add_call_destinations() such that it can override
+ * dead_end_function() marks.
+ */
+ ret = read_annotate(file, __annotate_late);
if (ret)
return ret;
@@ -2975,10 +2870,27 @@ static int update_cfi_state(struct instruction *insn,
break;
}
- if (op->dest.reg == CFI_SP && op->src.reg == CFI_BP) {
+ if (op->dest.reg == CFI_BP && op->src.reg == CFI_SP &&
+ insn->sym->frame_pointer) {
+ /* addi.d fp,sp,imm on LoongArch */
+ if (cfa->base == CFI_SP && cfa->offset == op->src.offset) {
+ cfa->base = CFI_BP;
+ cfa->offset = 0;
+ }
+ break;
+ }
- /* lea disp(%rbp), %rsp */
- cfi->stack_size = -(op->src.offset + regs[CFI_BP].offset);
+ if (op->dest.reg == CFI_SP && op->src.reg == CFI_BP) {
+ /* addi.d sp,fp,imm on LoongArch */
+ if (cfa->base == CFI_BP && cfa->offset == 0) {
+ if (insn->sym->frame_pointer) {
+ cfa->base = CFI_SP;
+ cfa->offset = -op->src.offset;
+ }
+ } else {
+ /* lea disp(%rbp), %rsp */
+ cfi->stack_size = -(op->src.offset + regs[CFI_BP].offset);
+ }
break;
}
@@ -3620,6 +3532,18 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
}
if (!save_insn->visited) {
+ /*
+ * If the restore hint insn is at the
+ * beginning of a basic block and was
+ * branched to from elsewhere, and the
+ * save insn hasn't been visited yet,
+ * defer following this branch for now.
+ * It will be seen later via the
+ * straight-line path.
+ */
+ if (!prev_insn)
+ return 0;
+
WARN_INSN(insn, "objtool isn't smart enough to handle this CFI save/restore combo");
return 1;
}
@@ -3723,9 +3647,12 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
break;
case INSN_CONTEXT_SWITCH:
- if (func && (!next_insn || !next_insn->hint)) {
- WARN_INSN(insn, "unsupported instruction in callable function");
- return 1;
+ if (func) {
+ if (!next_insn || !next_insn->hint) {
+ WARN_INSN(insn, "unsupported instruction in callable function");
+ return 1;
+ }
+ break;
}
return 0;
@@ -3980,11 +3907,11 @@ static int validate_retpoline(struct objtool_file *file)
if (insn->type == INSN_RETURN) {
if (opts.rethunk) {
- WARN_INSN(insn, "'naked' return found in RETHUNK build");
+ WARN_INSN(insn, "'naked' return found in MITIGATION_RETHUNK build");
} else
continue;
} else {
- WARN_INSN(insn, "indirect %s found in RETPOLINE build",
+ WARN_INSN(insn, "indirect %s found in MITIGATION_RETPOLINE build",
insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call");
}
@@ -4295,6 +4222,51 @@ static bool noendbr_range(struct objtool_file *file, struct instruction *insn)
return insn->offset == sym->offset + sym->len;
}
+static int __validate_ibt_insn(struct objtool_file *file, struct instruction *insn,
+ struct instruction *dest)
+{
+ if (dest->type == INSN_ENDBR) {
+ mark_endbr_used(dest);
+ return 0;
+ }
+
+ if (insn_func(dest) && insn_func(insn) &&
+ insn_func(dest)->pfunc == insn_func(insn)->pfunc) {
+ /*
+ * Anything from->to self is either _THIS_IP_ or
+ * IRET-to-self.
+ *
+ * There is no sane way to annotate _THIS_IP_ since the
+ * compiler treats the relocation as a constant and is
+ * happy to fold in offsets, skewing any annotation we
+ * do, leading to vast amounts of false-positives.
+ *
+ * There's also compiler generated _THIS_IP_ through
+ * KCOV and such which we have no hope of annotating.
+ *
+ * As such, blanket accept self-references without
+ * issue.
+ */
+ return 0;
+ }
+
+ /*
+ * Accept anything ANNOTATE_NOENDBR.
+ */
+ if (dest->noendbr)
+ return 0;
+
+ /*
+ * Accept if this is the instruction after a symbol
+ * that is (no)endbr -- typical code-range usage.
+ */
+ if (noendbr_range(file, dest))
+ return 0;
+
+ WARN_INSN(insn, "relocation to !ENDBR: %s", offstr(dest->sec, dest->offset));
+ return 1;
+}
+
static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn)
{
struct instruction *dest;
@@ -4307,6 +4279,7 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn
* direct/indirect branches:
*/
switch (insn->type) {
+
case INSN_CALL:
case INSN_CALL_DYNAMIC:
case INSN_JUMP_CONDITIONAL:
@@ -4316,6 +4289,23 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn
case INSN_RETURN:
case INSN_NOP:
return 0;
+
+ case INSN_LEA_RIP:
+ if (!insn_reloc(file, insn)) {
+ /* local function pointer reference without reloc */
+
+ off = arch_jump_destination(insn);
+
+ dest = find_insn(file, insn->sec, off);
+ if (!dest) {
+ WARN_INSN(insn, "corrupt function pointer reference");
+ return 1;
+ }
+
+ return __validate_ibt_insn(file, insn, dest);
+ }
+ break;
+
default:
break;
}
@@ -4326,13 +4316,6 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn
reloc_offset(reloc) + 1,
(insn->offset + insn->len) - (reloc_offset(reloc) + 1))) {
- /*
- * static_call_update() references the trampoline, which
- * doesn't have (or need) ENDBR. Skip warning in that case.
- */
- if (reloc->sym->static_call_tramp)
- continue;
-
off = reloc->sym->offset;
if (reloc_type(reloc) == R_X86_64_PC32 ||
reloc_type(reloc) == R_X86_64_PLT32)
@@ -4344,47 +4327,7 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn
if (!dest)
continue;
- if (dest->type == INSN_ENDBR) {
- mark_endbr_used(dest);
- continue;
- }
-
- if (insn_func(dest) && insn_func(insn) &&
- insn_func(dest)->pfunc == insn_func(insn)->pfunc) {
- /*
- * Anything from->to self is either _THIS_IP_ or
- * IRET-to-self.
- *
- * There is no sane way to annotate _THIS_IP_ since the
- * compiler treats the relocation as a constant and is
- * happy to fold in offsets, skewing any annotation we
- * do, leading to vast amounts of false-positives.
- *
- * There's also compiler generated _THIS_IP_ through
- * KCOV and such which we have no hope of annotating.
- *
- * As such, blanket accept self-references without
- * issue.
- */
- continue;
- }
-
- /*
- * Accept anything ANNOTATE_NOENDBR.
- */
- if (dest->noendbr)
- continue;
-
- /*
- * Accept if this is the instruction after a symbol
- * that is (no)endbr -- typical code-range usage.
- */
- if (noendbr_range(file, dest))
- continue;
-
- WARN_INSN(insn, "relocation to !ENDBR: %s", offstr(dest->sec, dest->offset));
-
- warnings++;
+ warnings += __validate_ibt_insn(file, insn, dest);
}
return warnings;
@@ -4460,6 +4403,9 @@ static int validate_ibt(struct objtool_file *file)
!strcmp(sec->name, "__jump_table") ||
!strcmp(sec->name, "__mcount_loc") ||
!strcmp(sec->name, ".kcfi_traps") ||
+ !strcmp(sec->name, ".llvm.call-graph-profile") ||
+ !strcmp(sec->name, ".llvm_bb_addr_map") ||
+ !strcmp(sec->name, "__tracepoints") ||
strstr(sec->name, "__patchable_function_entries"))
continue;