From 99ce7962d52d1948ad6f2785e308d48e76e0a6ef Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 8 Feb 2018 14:02:32 +0100 Subject: objtool: Fix switch-table detection Linus reported that GCC-7.3 generated a switch-table construct that confused objtool. It turns out that, in particular due to KASAN, it is possible to have unrelated .rodata usage in between the .rodata setup for the switch-table and the following indirect jump. The simple linear reverse search from the indirect jump would hit upon the KASAN .rodata usage first and fail to find a switch_table, resulting in a spurious 'sibling call with modified stack frame' warning. Fix this by creating a 'jump-stack' which we can 'unwind' during reversal, thereby skipping over much of the in-between code. This is not fool proof by any means, but is sufficient to make the known cases work. Future work would be to construct more comprehensive flow analysis code. Reported-and-tested-by: Linus Torvalds Signed-off-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Cc: Borislav Petkov Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180208130232.GF25235@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar --- tools/objtool/check.c | 41 +++++++++++++++++++++++++++++++++++++++-- tools/objtool/check.h | 1 + 2 files changed, 40 insertions(+), 2 deletions(-) (limited to 'tools/objtool') diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 9cd028aa1509..2e458eb45586 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -851,8 +851,14 @@ static int add_switch_table(struct objtool_file *file, struct symbol *func, * This is a fairly uncommon pattern which is new for GCC 6. As of this * writing, there are 11 occurrences of it in the allmodconfig kernel. * + * As of GCC 7 there are quite a few more of these and the 'in between' code + * is significant. Esp. with KASAN enabled some of the code between the mov + * and jmpq uses .rodata itself, which can confuse things. + * * TODO: Once we have DWARF CFI and smarter instruction decoding logic, * ensure the same register is used in the mov and jump instructions. + * + * NOTE: RETPOLINE made it harder still to decode dynamic jumps. */ static struct rela *find_switch_table(struct objtool_file *file, struct symbol *func, @@ -874,12 +880,25 @@ static struct rela *find_switch_table(struct objtool_file *file, text_rela->addend + 4); if (!rodata_rela) return NULL; + file->ignore_unreachables = true; return rodata_rela; } /* case 3 */ - func_for_each_insn_continue_reverse(file, func, insn) { + /* + * Backward search using the @first_jump_src links, these help avoid + * much of the 'in between' code. Which avoids us getting confused by + * it. + */ + for (insn = list_prev_entry(insn, list); + + &insn->list != &file->insn_list && + insn->sec == func->sec && + insn->offset >= func->offset; + + insn = insn->first_jump_src ?: list_prev_entry(insn, list)) { + if (insn->type == INSN_JUMP_DYNAMIC) break; @@ -909,14 +928,32 @@ static struct rela *find_switch_table(struct objtool_file *file, return NULL; } + static int add_func_switch_tables(struct objtool_file *file, struct symbol *func) { - struct instruction *insn, *prev_jump = NULL; + struct instruction *insn, *last = NULL, *prev_jump = NULL; struct rela *rela, *prev_rela = NULL; int ret; func_for_each_insn(file, func, insn) { + if (!last) + last = insn; + + /* + * Store back-pointers for unconditional forward jumps such + * that find_switch_table() can back-track using those and + * avoid some potentially confusing code. + */ + if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest && + insn->offset > last->offset && + insn->jump_dest->offset > insn->offset && + !insn->jump_dest->first_jump_src) { + + insn->jump_dest->first_jump_src = insn; + last = insn->jump_dest; + } + if (insn->type != INSN_JUMP_DYNAMIC) continue; diff --git a/tools/objtool/check.h b/tools/objtool/check.h index dbadb304a410..23a1d065cae1 100644 --- a/tools/objtool/check.h +++ b/tools/objtool/check.h @@ -47,6 +47,7 @@ struct instruction { bool alt_group, visited, dead_end, ignore, hint, save, restore, ignore_alts; struct symbol *call_dest; struct instruction *jump_dest; + struct instruction *first_jump_src; struct list_head alts; struct symbol *func; struct stack_op stack_op; -- cgit v1.2.3 From fe24e27128252c230a34a6c628da2bf1676781ea Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Thu, 8 Feb 2018 17:09:25 -0600 Subject: objtool: Fix segfault in ignore_unreachable_insn() Peter Zijlstra's patch for converting WARN() to use UD2 triggered a bunch of false "unreachable instruction" warnings, which then triggered a seg fault in ignore_unreachable_insn(). The seg fault happened when it tried to dereference a NULL 'insn->func' pointer. Thanks to static_cpu_has(), some functions can jump to a non-function area in the .altinstr_aux section. That breaks ignore_unreachable_insn()'s assumption that it's always inside the original function. Make sure ignore_unreachable_insn() only follows jumps within the current function. Reported-by: Borislav Petkov Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: kbuild test robot Link: http://lkml.kernel.org/r/bace77a60d5af9b45eddb8f8fb9c776c8de657ef.1518130694.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- tools/objtool/check.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'tools/objtool') diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 2e458eb45586..c7fb5c2392ee 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1935,13 +1935,19 @@ static bool ignore_unreachable_insn(struct instruction *insn) if (is_kasan_insn(insn) || is_ubsan_insn(insn)) return true; - if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest) { - insn = insn->jump_dest; - continue; + if (insn->type == INSN_JUMP_UNCONDITIONAL) { + if (insn->jump_dest && + insn->jump_dest->func == insn->func) { + insn = insn->jump_dest; + continue; + } + + break; } if (insn->offset + insn->len >= insn->func->offset + insn->func->len) break; + insn = list_next_entry(insn, list); } -- cgit v1.2.3 From 43a4525f80534530077683f6472d8971646b0ace Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 16 Jan 2018 17:16:32 +0100 Subject: objtool: Use existing global variables for options Use the existing global variables instead of passing them around and creating duplicate global variables. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Thomas Gleixner Acked-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: Dave Hansen Cc: David Woodhouse Cc: Greg Kroah-Hartman Cc: Linus Torvalds Cc: Peter Zijlstra Signed-off-by: Ingo Molnar --- tools/objtool/builtin-check.c | 2 +- tools/objtool/builtin-orc.c | 6 +----- tools/objtool/builtin.h | 5 +++++ tools/objtool/check.c | 5 ++--- tools/objtool/check.h | 2 +- 5 files changed, 10 insertions(+), 10 deletions(-) (limited to 'tools/objtool') diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 57254f5b2779..8d0986d2a803 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -53,5 +53,5 @@ int cmd_check(int argc, const char **argv) objname = argv[0]; - return check(objname, no_fp, no_unreachable, false); + return check(objname, false); } diff --git a/tools/objtool/builtin-orc.c b/tools/objtool/builtin-orc.c index 91e8e19ff5e0..77ea2b97117d 100644 --- a/tools/objtool/builtin-orc.c +++ b/tools/objtool/builtin-orc.c @@ -25,7 +25,6 @@ */ #include -#include #include "builtin.h" #include "check.h" @@ -36,9 +35,6 @@ static const char *orc_usage[] = { NULL, }; -extern const struct option check_options[]; -extern bool no_fp, no_unreachable; - int cmd_orc(int argc, const char **argv) { const char *objname; @@ -54,7 +50,7 @@ int cmd_orc(int argc, const char **argv) objname = argv[0]; - return check(objname, no_fp, no_unreachable, true); + return check(objname, true); } if (!strcmp(argv[0], "dump")) { diff --git a/tools/objtool/builtin.h b/tools/objtool/builtin.h index dd526067fed5..f166ea1b1da2 100644 --- a/tools/objtool/builtin.h +++ b/tools/objtool/builtin.h @@ -17,6 +17,11 @@ #ifndef _BUILTIN_H #define _BUILTIN_H +#include + +extern const struct option check_options[]; +extern bool no_fp, no_unreachable; + extern int cmd_check(int argc, const char **argv); extern int cmd_orc(int argc, const char **argv); diff --git a/tools/objtool/check.c b/tools/objtool/check.c index a8cb69a26576..ab6f0de7f90d 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -18,6 +18,7 @@ #include #include +#include "builtin.h" #include "check.h" #include "elf.h" #include "special.h" @@ -33,7 +34,6 @@ struct alternative { }; const char *objname; -static bool no_fp; struct cfi_state initial_func_cfi; struct instruction *find_insn(struct objtool_file *file, @@ -2022,13 +2022,12 @@ static void cleanup(struct objtool_file *file) elf_close(file->elf); } -int check(const char *_objname, bool _no_fp, bool no_unreachable, bool orc) +int check(const char *_objname, bool orc) { struct objtool_file file; int ret, warnings = 0; objname = _objname; - no_fp = _no_fp; file.elf = elf_open(objname, orc ? O_RDWR : O_RDONLY); if (!file.elf) diff --git a/tools/objtool/check.h b/tools/objtool/check.h index 23a1d065cae1..936255ba23db 100644 --- a/tools/objtool/check.h +++ b/tools/objtool/check.h @@ -63,7 +63,7 @@ struct objtool_file { bool ignore_unreachables, c_file, hints; }; -int check(const char *objname, bool no_fp, bool no_unreachable, bool orc); +int check(const char *objname, bool orc); struct instruction *find_insn(struct objtool_file *file, struct section *sec, unsigned long offset); -- cgit v1.2.3 From b5bc2231b8ad4387c9641f235ca0ad8cd300b6df Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 16 Jan 2018 10:24:06 +0100 Subject: objtool: Add retpoline validation David requested a objtool validation pass for CONFIG_RETPOLINE=y enabled builds, where it validates no unannotated indirect jumps or calls are left. Add an additional .discard.retpoline_safe section to allow annotating the few indirect sites that are required and safe. Requested-by: David Woodhouse Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: David Woodhouse Acked-by: Thomas Gleixner Acked-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: Dave Hansen Cc: Greg Kroah-Hartman Cc: Linus Torvalds Cc: Peter Zijlstra Signed-off-by: Ingo Molnar --- scripts/Makefile.build | 4 ++ tools/objtool/builtin-check.c | 3 +- tools/objtool/builtin.h | 2 +- tools/objtool/check.c | 86 ++++++++++++++++++++++++++++++++++++++++++- tools/objtool/check.h | 1 + 5 files changed, 93 insertions(+), 3 deletions(-) (limited to 'tools/objtool') diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 47cddf32aeba..53d862aee335 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -264,6 +264,10 @@ objtool_args += --no-unreachable else objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable) endif +ifdef CONFIG_RETPOLINE + objtool_args += --retpoline +endif + ifdef CONFIG_MODVERSIONS objtool_o = $(@D)/.tmp_$(@F) diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 8d0986d2a803..dd6bcd6097f5 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -29,7 +29,7 @@ #include "builtin.h" #include "check.h" -bool no_fp, no_unreachable; +bool no_fp, no_unreachable, retpoline; static const char * const check_usage[] = { "objtool check [] file.o", @@ -39,6 +39,7 @@ static const char * const check_usage[] = { const struct option check_options[] = { OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"), OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"), + OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"), OPT_END(), }; diff --git a/tools/objtool/builtin.h b/tools/objtool/builtin.h index f166ea1b1da2..7b6addfce045 100644 --- a/tools/objtool/builtin.h +++ b/tools/objtool/builtin.h @@ -20,7 +20,7 @@ #include extern const struct option check_options[]; -extern bool no_fp, no_unreachable; +extern bool no_fp, no_unreachable, retpoline; extern int cmd_check(int argc, const char **argv); extern int cmd_orc(int argc, const char **argv); diff --git a/tools/objtool/check.c b/tools/objtool/check.c index ab6f0de7f90d..5e5db7b4d77b 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -497,6 +497,7 @@ static int add_jump_destinations(struct objtool_file *file) * disguise, so convert them accordingly. */ insn->type = INSN_JUMP_DYNAMIC; + insn->retpoline_safe = true; continue; } else { /* sibling call */ @@ -548,7 +549,8 @@ static int add_call_destinations(struct objtool_file *file) if (!insn->call_dest && !insn->ignore) { WARN_FUNC("unsupported intra-function call", insn->sec, insn->offset); - WARN("If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE."); + if (retpoline) + WARN("If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE."); return -1; } @@ -1108,6 +1110,54 @@ static int read_unwind_hints(struct objtool_file *file) return 0; } +static int read_retpoline_hints(struct objtool_file *file) +{ + struct section *sec, *relasec; + struct instruction *insn; + struct rela *rela; + int i; + + sec = find_section_by_name(file->elf, ".discard.retpoline_safe"); + if (!sec) + return 0; + + relasec = sec->rela; + if (!relasec) { + WARN("missing .rela.discard.retpoline_safe section"); + return -1; + } + + if (sec->len % sizeof(unsigned long)) { + WARN("retpoline_safe size mismatch: %d %ld", sec->len, sizeof(unsigned long)); + return -1; + } + + for (i = 0; i < sec->len / sizeof(unsigned long); i++) { + rela = find_rela_by_dest(sec, i * sizeof(unsigned long)); + if (!rela) { + WARN("can't find rela for retpoline_safe[%d]", i); + return -1; + } + + insn = find_insn(file, rela->sym->sec, rela->addend); + if (!insn) { + WARN("can't find insn for retpoline_safe[%d]", i); + return -1; + } + + if (insn->type != INSN_JUMP_DYNAMIC && + insn->type != INSN_CALL_DYNAMIC) { + WARN_FUNC("retpoline_safe hint not a indirect jump/call", + insn->sec, insn->offset); + return -1; + } + + insn->retpoline_safe = true; + } + + return 0; +} + static int decode_sections(struct objtool_file *file) { int ret; @@ -1146,6 +1196,10 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret; + ret = read_retpoline_hints(file); + if (ret) + return ret; + return 0; } @@ -1891,6 +1945,29 @@ static int validate_unwind_hints(struct objtool_file *file) return warnings; } +static int validate_retpoline(struct objtool_file *file) +{ + struct instruction *insn; + int warnings = 0; + + for_each_insn(file, insn) { + if (insn->type != INSN_JUMP_DYNAMIC && + insn->type != INSN_CALL_DYNAMIC) + continue; + + if (insn->retpoline_safe) + continue; + + WARN_FUNC("indirect %s found in RETPOLINE build", + insn->sec, insn->offset, + insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call"); + + warnings++; + } + + return warnings; +} + static bool is_kasan_insn(struct instruction *insn) { return (insn->type == INSN_CALL && @@ -2051,6 +2128,13 @@ int check(const char *_objname, bool orc) if (list_empty(&file.insn_list)) goto out; + if (retpoline) { + ret = validate_retpoline(&file); + if (ret < 0) + return ret; + warnings += ret; + } + ret = validate_functions(&file); if (ret < 0) goto out; diff --git a/tools/objtool/check.h b/tools/objtool/check.h index 936255ba23db..c6b68fcb926f 100644 --- a/tools/objtool/check.h +++ b/tools/objtool/check.h @@ -45,6 +45,7 @@ struct instruction { unsigned char 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; -- cgit v1.2.3 From ca41b97ed9124fd62323a162de5852f6e28f94b8 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 31 Jan 2018 10:18:28 +0100 Subject: objtool: Add module specific retpoline rules David allowed retpolines in .init.text, except for modules, which will trip up objtool retpoline validation, fix that. Requested-by: David Woodhouse Signed-off-by: Peter Zijlstra (Intel) Acked-by: Thomas Gleixner Acked-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: Dave Hansen Cc: David Woodhouse Cc: Greg Kroah-Hartman Cc: Linus Torvalds Cc: Peter Zijlstra Signed-off-by: Ingo Molnar --- scripts/Makefile.build | 2 ++ tools/objtool/builtin-check.c | 3 ++- tools/objtool/builtin.h | 2 +- tools/objtool/check.c | 9 +++++++++ 4 files changed, 14 insertions(+), 2 deletions(-) (limited to 'tools/objtool') diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 53d862aee335..ce0fc4dd68c6 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -256,6 +256,8 @@ __objtool_obj := $(objtree)/tools/objtool/objtool objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check) +objtool_args += $(if $(part-of-module), --module,) + ifndef CONFIG_FRAME_POINTER objtool_args += --no-fp endif diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index dd6bcd6097f5..694abc628e9b 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -29,7 +29,7 @@ #include "builtin.h" #include "check.h" -bool no_fp, no_unreachable, retpoline; +bool no_fp, no_unreachable, retpoline, module; static const char * const check_usage[] = { "objtool check [] file.o", @@ -40,6 +40,7 @@ const struct option check_options[] = { OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"), OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"), OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"), + OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"), OPT_END(), }; diff --git a/tools/objtool/builtin.h b/tools/objtool/builtin.h index 7b6addfce045..28ff40e19a14 100644 --- a/tools/objtool/builtin.h +++ b/tools/objtool/builtin.h @@ -20,7 +20,7 @@ #include extern const struct option check_options[]; -extern bool no_fp, no_unreachable, retpoline; +extern bool no_fp, no_unreachable, retpoline, module; extern int cmd_check(int argc, const char **argv); extern int cmd_orc(int argc, const char **argv); diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 5e5db7b4d77b..472e64e95891 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1958,6 +1958,15 @@ static int validate_retpoline(struct objtool_file *file) if (insn->retpoline_safe) continue; + /* + * .init.text code is ran before userspace and thus doesn't + * strictly need retpolines, except for modules which are + * loaded late, they very much do need retpoline in their + * .init.text + */ + if (!strcmp(insn->sec->name, ".init.text") && !module) + continue; + WARN_FUNC("indirect %s found in RETPOLINE build", insn->sec, insn->offset, insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call"); -- cgit v1.2.3 From 1402fd8ed7e5bda1b3e7613b70780b0db392d1e6 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 28 Feb 2018 07:19:21 -0600 Subject: objtool: Fix another switch table detection issue Continue the switch table detection whack-a-mole. Add a check to distinguish KASAN data reads from switch data reads. The switch jump tables in .rodata have relocations associated with them. This fixes the following warning: crypto/asymmetric_keys/x509_cert_parser.o: warning: objtool: x509_note_pkey_algo()+0xa4: sibling call from callable instruction with modified stack frame Reported-by: Arnd Bergmann Signed-off-by: Josh Poimboeuf Signed-off-by: Thomas Gleixner Tested-by: Arnd Bergmann Cc: Peter Zijlstra Link: https://lkml.kernel.org/r/d7c8853022ad47d158cb81e953a40469fc08a95e.1519784382.git.jpoimboe@redhat.com --- tools/objtool/check.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'tools/objtool') diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 472e64e95891..46c1d239cc1b 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -925,7 +925,11 @@ static struct rela *find_switch_table(struct objtool_file *file, if (find_symbol_containing(file->rodata, text_rela->addend)) continue; - return find_rela_by_dest(file->rodata, text_rela->addend); + rodata_rela = find_rela_by_dest(file->rodata, text_rela->addend); + if (!rodata_rela) + continue; + + return rodata_rela; } return NULL; -- cgit v1.2.3 From 63474dc4ac7ed3848a4786b9592dd061901f606d Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 6 Mar 2018 17:58:15 -0600 Subject: objtool: Fix 32-bit build Fix the objtool build when cross-compiling a 64-bit kernel on a 32-bit host. This also simplifies read_retpoline_hints() a bit and makes its implementation similar to most of the other annotation reading functions. Reported-by: Sven Joachim Signed-off-by: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: b5bc2231b8ad ("objtool: Add retpoline validation") Link: http://lkml.kernel.org/r/2ca46c636c23aa9c9d57d53c75de4ee3ddf7a7df.1520380691.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- tools/objtool/check.c | 27 +++++++-------------------- 1 file changed, 7 insertions(+), 20 deletions(-) (limited to 'tools/objtool') diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 46c1d239cc1b..92b6a2c21631 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1116,42 +1116,29 @@ static int read_unwind_hints(struct objtool_file *file) static int read_retpoline_hints(struct objtool_file *file) { - struct section *sec, *relasec; + struct section *sec; struct instruction *insn; struct rela *rela; - int i; - sec = find_section_by_name(file->elf, ".discard.retpoline_safe"); + sec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe"); if (!sec) return 0; - relasec = sec->rela; - if (!relasec) { - WARN("missing .rela.discard.retpoline_safe section"); - return -1; - } - - if (sec->len % sizeof(unsigned long)) { - WARN("retpoline_safe size mismatch: %d %ld", sec->len, sizeof(unsigned long)); - return -1; - } - - for (i = 0; i < sec->len / sizeof(unsigned long); i++) { - rela = find_rela_by_dest(sec, i * sizeof(unsigned long)); - if (!rela) { - WARN("can't find rela for retpoline_safe[%d]", i); + list_for_each_entry(rela, &sec->rela_list, list) { + if (rela->sym->type != STT_SECTION) { + WARN("unexpected relocation symbol type in %s", sec->name); return -1; } insn = find_insn(file, rela->sym->sec, rela->addend); if (!insn) { - WARN("can't find insn for retpoline_safe[%d]", i); + WARN("bad .discard.retpoline_safe entry"); return -1; } if (insn->type != INSN_JUMP_DYNAMIC && insn->type != INSN_CALL_DYNAMIC) { - WARN_FUNC("retpoline_safe hint not a indirect jump/call", + WARN_FUNC("retpoline_safe hint not an indirect jump/call", insn->sec, insn->offset); return -1; } -- cgit v1.2.3