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authorLinus Torvalds <torvalds@linux-foundation.org>2024-11-19 13:27:52 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2024-11-19 13:27:52 -0800
commit9d7d4ad222aea8ab482e78858d03b10221c7fe78 (patch)
treeb2e29edb5e4cdda157f629295cae0aaf1efab94f /tools
parent364eeb79a213fcf9164208b53764223ad522d6b3 (diff)
parentd5173f7537505315557d8580e3a648f07f17deda (diff)
Merge tag 'objtool-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar: - Detect non-relocated text references for more robust IBT sealing (Josh Poimboeuf) - Fix build error when building stripped down UAPI headers (HONG Yifan) - Exclude __tracepoints data from ENDBR checks to fix false positives on clang builds (Peter Zijlstra) - Fix ORC unwind for newly forked tasks (Zheng Yejian) - Fix readelf related faddr2line regression (Carlos Llamas) * tag 'objtool-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Exclude __tracepoints data from ENDBR checks Revert "scripts/faddr2line: Check only two symbols when calculating symbol size" x86/unwind/orc: Fix unwind for newly forked tasks objtool: Also include tools/include/uapi objtool: Detect non-relocated text references
Diffstat (limited to 'tools')
-rw-r--r--tools/objtool/Makefile1
-rw-r--r--tools/objtool/arch/x86/decode.c15
-rw-r--r--tools/objtool/check.c113
-rw-r--r--tools/objtool/include/objtool/arch.h1
4 files changed, 77 insertions, 53 deletions
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index bf7f7f84ac62..f56e27727534 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -24,6 +24,7 @@ LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lel
all: $(OBJTOOL)
INCLUDES := -I$(srctree)/tools/include \
+ -I$(srctree)/tools/include/uapi \
-I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
-I$(srctree)/tools/arch/$(SRCARCH)/include \
-I$(srctree)/tools/objtool/include \
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index ed6bff0e01dc..fe1362c34564 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -456,10 +456,6 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
if (!rex_w)
break;
- /* skip RIP relative displacement */
- if (is_RIP())
- break;
-
/* skip nontrivial SIB */
if (have_SIB()) {
modrm_rm = sib_base;
@@ -467,6 +463,12 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
break;
}
+ /* lea disp(%rip), %dst */
+ if (is_RIP()) {
+ insn->type = INSN_LEA_RIP;
+ break;
+ }
+
/* lea disp(%src), %dst */
ADD_OP(op) {
op->src.offset = ins.displacement.value;
@@ -737,7 +739,10 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
break;
}
- insn->immediate = ins.immediate.nbytes ? ins.immediate.value : 0;
+ if (ins.immediate.nbytes)
+ insn->immediate = ins.immediate.value;
+ else if (ins.displacement.nbytes)
+ insn->immediate = ins.displacement.value;
return 0;
}
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 6604f5d038aa..f7586f82b967 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4392,6 +4392,51 @@ 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;
@@ -4404,6 +4449,7 @@ 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:
@@ -4413,6 +4459,23 @@ 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;
}
@@ -4423,13 +4486,6 @@ 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)
@@ -4441,47 +4497,7 @@ 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;
@@ -4557,6 +4573,7 @@ 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, "__tracepoints") ||
strstr(sec->name, "__patchable_function_entries"))
continue;
diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h
index 0b303eba660e..d63b46a19f39 100644
--- a/tools/objtool/include/objtool/arch.h
+++ b/tools/objtool/include/objtool/arch.h
@@ -28,6 +28,7 @@ enum insn_type {
INSN_CLD,
INSN_TRAP,
INSN_ENDBR,
+ INSN_LEA_RIP,
INSN_OTHER,
};