This is a note to let you know that I've just added the patch titled
objtool: Refactor ORC section generation
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
objtool-refactor-orc-section-generation.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Tue Jul 12 05:07:35 PM CEST 2022
From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Date: Thu, 17 Dec 2020 15:02:42 -0600
Subject: objtool: Refactor ORC section generation
From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
commit ab4e0744e99b87e1a223e89fc3c9ae44f727c9a6 upstream.
Decouple ORC entries from instructions. This simplifies the
control/data flow, and is going to make it easier to support alternative
instructions which change the stack layout.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/objtool/Makefile | 4
tools/objtool/arch.h | 4
tools/objtool/builtin-orc.c | 6
tools/objtool/check.h | 3
tools/objtool/objtool.h | 3
tools/objtool/orc_gen.c | 274 ++++++++++++++++++++++----------------------
tools/objtool/weak.c | 7 -
7 files changed, 141 insertions(+), 160 deletions(-)
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -46,10 +46,6 @@ ifeq ($(SRCARCH),x86)
SUBCMD_ORC := y
endif
-ifeq ($(SUBCMD_ORC),y)
- CFLAGS += -DINSN_USE_ORC
-endif
-
export SUBCMD_CHECK SUBCMD_ORC
export srctree OUTPUT CFLAGS SRCARCH AWK
include $(srctree)/tools/build/Makefile.include
--- a/tools/objtool/arch.h
+++ b/tools/objtool/arch.h
@@ -11,10 +11,6 @@
#include "objtool.h"
#include "cfi.h"
-#ifdef INSN_USE_ORC
-#include <asm/orc_types.h>
-#endif
-
enum insn_type {
INSN_JUMP_CONDITIONAL,
INSN_JUMP_UNCONDITIONAL,
--- a/tools/objtool/builtin-orc.c
+++ b/tools/objtool/builtin-orc.c
@@ -51,11 +51,7 @@ int cmd_orc(int argc, const char **argv)
if (list_empty(&file->insn_list))
return 0;
- ret = create_orc(file);
- if (ret)
- return ret;
-
- ret = create_orc_sections(file);
+ ret = orc_create(file);
if (ret)
return ret;
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -43,9 +43,6 @@ struct instruction {
struct symbol *func;
struct list_head stack_ops;
struct cfi_state cfi;
-#ifdef INSN_USE_ORC
- struct orc_entry orc;
-#endif
};
static inline bool is_static_jump(struct instruction *insn)
--- a/tools/objtool/objtool.h
+++ b/tools/objtool/objtool.h
@@ -26,7 +26,6 @@ struct objtool_file *objtool_open_read(c
int check(struct objtool_file *file);
int orc_dump(const char *objname);
-int create_orc(struct objtool_file *file);
-int create_orc_sections(struct objtool_file *file);
+int orc_create(struct objtool_file *file);
#endif /* _OBJTOOL_H */
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -12,89 +12,84 @@
#include "check.h"
#include "warn.h"
-int create_orc(struct objtool_file *file)
+static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi)
{
- struct instruction *insn;
+ struct instruction *insn = container_of(cfi, struct instruction, cfi);
+ struct cfi_reg *bp = &cfi->regs[CFI_BP];
- for_each_insn(file, insn) {
- struct orc_entry *orc = &insn->orc;
- struct cfi_reg *cfa = &insn->cfi.cfa;
- struct cfi_reg *bp = &insn->cfi.regs[CFI_BP];
+ memset(orc, 0, sizeof(*orc));
- if (!insn->sec->text)
- continue;
-
- orc->end = insn->cfi.end;
-
- if (cfa->base == CFI_UNDEFINED) {
- orc->sp_reg = ORC_REG_UNDEFINED;
- continue;
- }
-
- switch (cfa->base) {
- case CFI_SP:
- orc->sp_reg = ORC_REG_SP;
- break;
- case CFI_SP_INDIRECT:
- orc->sp_reg = ORC_REG_SP_INDIRECT;
- break;
- case CFI_BP:
- orc->sp_reg = ORC_REG_BP;
- break;
- case CFI_BP_INDIRECT:
- orc->sp_reg = ORC_REG_BP_INDIRECT;
- break;
- case CFI_R10:
- orc->sp_reg = ORC_REG_R10;
- break;
- case CFI_R13:
- orc->sp_reg = ORC_REG_R13;
- break;
- case CFI_DI:
- orc->sp_reg = ORC_REG_DI;
- break;
- case CFI_DX:
- orc->sp_reg = ORC_REG_DX;
- break;
- default:
- WARN_FUNC("unknown CFA base reg %d",
- insn->sec, insn->offset, cfa->base);
- return -1;
- }
+ orc->end = cfi->end;
- switch(bp->base) {
- case CFI_UNDEFINED:
- orc->bp_reg = ORC_REG_UNDEFINED;
- break;
- case CFI_CFA:
- orc->bp_reg = ORC_REG_PREV_SP;
- break;
- case CFI_BP:
- orc->bp_reg = ORC_REG_BP;
- break;
- default:
- WARN_FUNC("unknown BP base reg %d",
- insn->sec, insn->offset, bp->base);
- return -1;
- }
+ if (cfi->cfa.base == CFI_UNDEFINED) {
+ orc->sp_reg = ORC_REG_UNDEFINED;
+ return 0;
+ }
+
+ switch (cfi->cfa.base) {
+ case CFI_SP:
+ orc->sp_reg = ORC_REG_SP;
+ break;
+ case CFI_SP_INDIRECT:
+ orc->sp_reg = ORC_REG_SP_INDIRECT;
+ break;
+ case CFI_BP:
+ orc->sp_reg = ORC_REG_BP;
+ break;
+ case CFI_BP_INDIRECT:
+ orc->sp_reg = ORC_REG_BP_INDIRECT;
+ break;
+ case CFI_R10:
+ orc->sp_reg = ORC_REG_R10;
+ break;
+ case CFI_R13:
+ orc->sp_reg = ORC_REG_R13;
+ break;
+ case CFI_DI:
+ orc->sp_reg = ORC_REG_DI;
+ break;
+ case CFI_DX:
+ orc->sp_reg = ORC_REG_DX;
+ break;
+ default:
+ WARN_FUNC("unknown CFA base reg %d",
+ insn->sec, insn->offset, cfi->cfa.base);
+ return -1;
+ }
- orc->sp_offset = cfa->offset;
- orc->bp_offset = bp->offset;
- orc->type = insn->cfi.type;
+ switch (bp->base) {
+ case CFI_UNDEFINED:
+ orc->bp_reg = ORC_REG_UNDEFINED;
+ break;
+ case CFI_CFA:
+ orc->bp_reg = ORC_REG_PREV_SP;
+ break;
+ case CFI_BP:
+ orc->bp_reg = ORC_REG_BP;
+ break;
+ default:
+ WARN_FUNC("unknown BP base reg %d",
+ insn->sec, insn->offset, bp->base);
+ return -1;
}
+ orc->sp_offset = cfi->cfa.offset;
+ orc->bp_offset = bp->offset;
+ orc->type = cfi->type;
+
return 0;
}
-static int create_orc_entry(struct elf *elf, struct section *u_sec, struct section *ip_relocsec,
- unsigned int idx, struct section *insn_sec,
- unsigned long insn_off, struct orc_entry *o)
+static int write_orc_entry(struct elf *elf, struct section *orc_sec,
+ struct section *ip_rsec, unsigned int idx,
+ struct section *insn_sec, unsigned long insn_off,
+ struct orc_entry *o)
{
struct orc_entry *orc;
struct reloc *reloc;
/* populate ORC data */
- orc = (struct orc_entry *)u_sec->data->d_buf + idx;
+ orc = (struct orc_entry *)orc_sec->data->d_buf + idx;
memcpy(orc, o, sizeof(*orc));
/* populate reloc for ip */
@@ -114,102 +109,109 @@ static int create_orc_entry(struct elf *
reloc->type = R_X86_64_PC32;
reloc->offset = idx * sizeof(int);
- reloc->sec = ip_relocsec;
+ reloc->sec = ip_rsec;
elf_add_reloc(elf, reloc);
return 0;
}
-int create_orc_sections(struct objtool_file *file)
+struct orc_list_entry {
+ struct list_head list;
+ struct orc_entry orc;
+ struct section *insn_sec;
+ unsigned long insn_off;
+};
+
+static int orc_list_add(struct list_head *orc_list, struct orc_entry *orc,
+ struct section *sec, unsigned long offset)
+{
+ struct orc_list_entry *entry = malloc(sizeof(*entry));
+
+ if (!entry) {
+ WARN("malloc failed");
+ return -1;
+ }
+
+ entry->orc = *orc;
+ entry->insn_sec = sec;
+ entry->insn_off = offset;
+
+ list_add_tail(&entry->list, orc_list);
+ return 0;
+}
+
+int orc_create(struct objtool_file *file)
{
- struct instruction *insn, *prev_insn;
- struct section *sec, *u_sec, *ip_relocsec;
- unsigned int idx;
+ struct section *sec, *ip_rsec, *orc_sec;
+ unsigned int nr = 0, idx = 0;
+ struct orc_list_entry *entry;
+ struct list_head orc_list;
- struct orc_entry empty = {
- .sp_reg = ORC_REG_UNDEFINED,
+ struct orc_entry null = {
+ .sp_reg = ORC_REG_UNDEFINED,
.bp_reg = ORC_REG_UNDEFINED,
.type = UNWIND_HINT_TYPE_CALL,
};
- sec = find_section_by_name(file->elf, ".orc_unwind");
- if (sec) {
- WARN("file already has .orc_unwind section, skipping");
- return -1;
- }
-
- /* count the number of needed orcs */
- idx = 0;
+ /* Build a deduplicated list of ORC entries: */
+ INIT_LIST_HEAD(&orc_list);
for_each_sec(file, sec) {
+ struct orc_entry orc, prev_orc = {0};
+ struct instruction *insn;
+ bool empty = true;
+
if (!sec->text)
continue;
- prev_insn = NULL;
sec_for_each_insn(file, sec, insn) {
- if (!prev_insn ||
- memcmp(&insn->orc, &prev_insn->orc,
- sizeof(struct orc_entry))) {
- idx++;
- }
- prev_insn = insn;
+ if (init_orc_entry(&orc, &insn->cfi))
+ return -1;
+ if (!memcmp(&prev_orc, &orc, sizeof(orc)))
+ continue;
+ if (orc_list_add(&orc_list, &orc, sec, insn->offset))
+ return -1;
+ nr++;
+ prev_orc = orc;
+ empty = false;
}
- /* section terminator */
- if (prev_insn)
- idx++;
+ /* Add a section terminator */
+ if (!empty) {
+ orc_list_add(&orc_list, &null, sec, sec->len);
+ nr++;
+ }
}
- if (!idx)
- return -1;
+ if (!nr)
+ return 0;
+ /* Create .orc_unwind, .orc_unwind_ip and .rela.orc_unwind_ip sections: */
+ sec = find_section_by_name(file->elf, ".orc_unwind");
+ if (sec) {
+ WARN("file already has .orc_unwind section, skipping");
+ return -1;
+ }
+ orc_sec = elf_create_section(file->elf, ".orc_unwind", 0,
+ sizeof(struct orc_entry), nr);
+ if (!orc_sec)
+ return -1;
- /* create .orc_unwind_ip and .rela.orc_unwind_ip sections */
- sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), idx);
+ sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), nr);
if (!sec)
return -1;
-
- ip_relocsec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
- if (!ip_relocsec)
+ ip_rsec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
+ if (!ip_rsec)
return -1;
- /* create .orc_unwind section */
- u_sec = elf_create_section(file->elf, ".orc_unwind", 0,
- sizeof(struct orc_entry), idx);
-
- /* populate sections */
- idx = 0;
- for_each_sec(file, sec) {
- if (!sec->text)
- continue;
-
- prev_insn = NULL;
- sec_for_each_insn(file, sec, insn) {
- if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc,
- sizeof(struct orc_entry))) {
-
- if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
- insn->sec, insn->offset,
- &insn->orc))
- return -1;
-
- idx++;
- }
- prev_insn = insn;
- }
-
- /* section terminator */
- if (prev_insn) {
- if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
- prev_insn->sec,
- prev_insn->offset + prev_insn->len,
- &empty))
- return -1;
-
- idx++;
- }
+ /* Write ORC entries to sections: */
+ list_for_each_entry(entry, &orc_list, list) {
+ if (write_orc_entry(file->elf, orc_sec, ip_rsec, idx++,
+ entry->insn_sec, entry->insn_off,
+ &entry->orc))
+ return -1;
}
- if (elf_rebuild_reloc_section(file->elf, ip_relocsec))
+ if (elf_rebuild_reloc_section(file->elf, ip_rsec))
return -1;
return 0;
--- a/tools/objtool/weak.c
+++ b/tools/objtool/weak.c
@@ -25,12 +25,7 @@ int __weak orc_dump(const char *_objname
UNSUPPORTED("orc");
}
-int __weak create_orc(struct objtool_file *file)
-{
- UNSUPPORTED("orc");
-}
-
-int __weak create_orc_sections(struct objtool_file *file)
+int __weak orc_create(struct objtool_file *file)
{
UNSUPPORTED("orc");
}
Patches currently in stable-queue which might be from jpoimboe@xxxxxxxxxx are
queue-5.10/x86-bugs-enable-stibp-for-jmp2ret.patch
queue-5.10/objtool-assume-only-elf-functions-do-sibling-calls.patch
queue-5.10/objtool-support-retpoline-jump-detection-for-vmlinux.o.patch
queue-5.10/x86-xen-support-objtool-vmlinux.o-validation-in-xen-head.s.patch
queue-5.10/objtool-x86-replace-alternatives-with-.retpoline_sites.patch
queue-5.10/objtool-don-t-make-.altinstructions-writable.patch
queue-5.10/x86-alternative-handle-jcc-__x86_indirect_thunk_-reg.patch
queue-5.10/x86-xen-support-objtool-validation-in-xen-asm.s.patch
queue-5.10/x86-retpoline-remove-unused-replacement-symbols.patch
queue-5.10/objtool-support-stack-layout-changes-in-alternatives.patch
queue-5.10/bpf-x86-respect-x86_feature_retpoline.patch
queue-5.10/objtool-fix-type-of-reloc-addend.patch
queue-5.10/x86-retpoline-create-a-retpoline-thunk-array.patch
queue-5.10/x86-asm-fix-register-order.patch
queue-5.10/objtool-make-.altinstructions-section-entry-size-consistent.patch
queue-5.10/bpf-x86-simplify-computing-label-offsets.patch
queue-5.10/objtool-refactor-orc-section-generation.patch
queue-5.10/objtool-fix-code-relocs-vs-weak-symbols.patch
queue-5.10/objtool-combine-unwind_hint_ret_offset-and-unwind_hint_func.patch
queue-5.10/x86-asm-fixup-odd-gen-for-each-reg.h-usage.patch
queue-5.10/x86-alternative-add-debug-prints-to-apply_retpolines.patch
queue-5.10/objtool-remove-reloc-symbol-type-checks-in-get_alt_entry.patch
queue-5.10/objtool-classify-symbols.patch
queue-5.10/objtool-add-alt_group-struct.patch
queue-5.10/x86-retpoline-move-the-retpoline-thunk-declarations-to-nospec-branch.h.patch
queue-5.10/objtool-support-asm-jump-tables.patch
queue-5.10/x86-alternative-implement-.retpoline_sites-support.patch
queue-5.10/x86-alternative-try-inline-spectre_v2-retpoline-amd.patch
queue-5.10/objtool-explicitly-avoid-self-modifying-code-in-.altinstr_replacement.patch
queue-5.10/objtool-create-reloc-sections-implicitly.patch
queue-5.10/objtool-default-ignore-int3-for-unreachable.patch
queue-5.10/objtool-teach-get_alt_entry-about-more-relocation-types.patch
