From: "tip-bot2 for Peter Zijlstra" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
linux@weissschuh.net, x86@kernel.org,
linux-kernel@vger.kernel.org
Subject: [tip: objtool/core] objtool: Fix overlapping alternatives
Date: Mon, 13 Feb 2023 11:10:28 -0000 [thread overview]
Message-ID: <167628662854.4906.18315456608077226990.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20230208172245.711471461@infradead.org>
The following commit has been merged into the objtool/core branch of tip:
Commit-ID: 339b90b37d80ff2f4064bf072584031f3b1b5838
Gitweb: https://git.kernel.org/tip/339b90b37d80ff2f4064bf072584031f3b1b5838
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Wed, 08 Feb 2023 18:18:03 +01:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 13 Feb 2023 11:26:08 +01:00
objtool: Fix overlapping alternatives
Things like ALTERNATIVE_{2,3}() generate multiple alternatives on the
same place, objtool would override the first orig_alt_group with the
second (or third), failing to check the CFI among all the different
variants.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org> # build only
Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run
Link: https://lore.kernel.org/r/20230208172245.711471461@infradead.org
---
tools/objtool/check.c | 69 ++++++++++++++++++++++++++----------------
1 file changed, 43 insertions(+), 26 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 6f0adb2..7e9d3d3 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1744,36 +1744,49 @@ static int handle_group_alt(struct objtool_file *file,
struct instruction *orig_insn,
struct instruction **new_insn)
{
- struct instruction *last_orig_insn, *last_new_insn = NULL, *insn, *nop = NULL;
+ struct instruction *last_new_insn = NULL, *insn, *nop = NULL;
struct alt_group *orig_alt_group, *new_alt_group;
unsigned long dest_off;
-
- orig_alt_group = malloc(sizeof(*orig_alt_group));
+ orig_alt_group = orig_insn->alt_group;
if (!orig_alt_group) {
- WARN("malloc failed");
- return -1;
- }
- orig_alt_group->cfi = calloc(special_alt->orig_len,
- sizeof(struct cfi_state *));
- if (!orig_alt_group->cfi) {
- WARN("calloc failed");
- return -1;
- }
+ struct instruction *last_orig_insn = NULL;
- last_orig_insn = NULL;
- insn = orig_insn;
- sec_for_each_insn_from(file, insn) {
- if (insn->offset >= special_alt->orig_off + special_alt->orig_len)
- break;
+ orig_alt_group = malloc(sizeof(*orig_alt_group));
+ if (!orig_alt_group) {
+ WARN("malloc failed");
+ return -1;
+ }
+ orig_alt_group->cfi = calloc(special_alt->orig_len,
+ sizeof(struct cfi_state *));
+ if (!orig_alt_group->cfi) {
+ WARN("calloc failed");
+ return -1;
+ }
- insn->alt_group = orig_alt_group;
- last_orig_insn = insn;
- }
- orig_alt_group->orig_group = NULL;
- orig_alt_group->first_insn = orig_insn;
- orig_alt_group->last_insn = last_orig_insn;
+ insn = orig_insn;
+ sec_for_each_insn_from(file, insn) {
+ if (insn->offset >= special_alt->orig_off + special_alt->orig_len)
+ break;
+ insn->alt_group = orig_alt_group;
+ last_orig_insn = insn;
+ }
+ orig_alt_group->orig_group = NULL;
+ orig_alt_group->first_insn = orig_insn;
+ orig_alt_group->last_insn = last_orig_insn;
+ } else {
+ if (orig_alt_group->last_insn->offset + orig_alt_group->last_insn->len -
+ orig_alt_group->first_insn->offset != special_alt->orig_len) {
+ WARN_FUNC("weirdly overlapping alternative! %ld != %d",
+ orig_insn->sec, orig_insn->offset,
+ orig_alt_group->last_insn->offset +
+ orig_alt_group->last_insn->len -
+ orig_alt_group->first_insn->offset,
+ special_alt->orig_len);
+ return -1;
+ }
+ }
new_alt_group = malloc(sizeof(*new_alt_group));
if (!new_alt_group) {
@@ -1848,7 +1861,7 @@ static int handle_group_alt(struct objtool_file *file,
dest_off = arch_jump_destination(insn);
if (dest_off == special_alt->new_off + special_alt->new_len) {
- insn->jump_dest = next_insn_same_sec(file, last_orig_insn);
+ insn->jump_dest = next_insn_same_sec(file, orig_alt_group->last_insn);
if (!insn->jump_dest) {
WARN_FUNC("can't find alternative jump destination",
insn->sec, insn->offset);
@@ -3226,8 +3239,12 @@ static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn
alt_cfi[group_off] = insn->cfi;
} else {
if (cficmp(alt_cfi[group_off], insn->cfi)) {
- WARN_FUNC("stack layout conflict in alternatives",
- insn->sec, insn->offset);
+ struct alt_group *orig_group = insn->alt_group->orig_group ?: insn->alt_group;
+ struct instruction *orig = orig_group->first_insn;
+ char *where = offstr(insn->sec, insn->offset);
+ WARN_FUNC("stack layout conflict in alternatives: %s",
+ orig->sec, orig->offset, where);
+ free(where);
return -1;
}
}
next prev parent reply other threads:[~2023-02-13 11:10 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-08 17:17 [PATCH 00/10] objtool: Honey, I shrunk the instruction Peter Zijlstra
2023-02-08 17:17 ` [PATCH 01/10] objtool: Change arch_decode_instruction() signature Peter Zijlstra
2023-02-13 11:10 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2023-02-23 8:32 ` tip-bot2 for Peter Zijlstra
2023-02-08 17:17 ` [PATCH 02/10] objtool: Make instruction::stack_ops a single-linked list Peter Zijlstra
2023-02-13 11:10 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2023-02-23 8:32 ` tip-bot2 for Peter Zijlstra
2023-02-08 17:17 ` [PATCH 03/10] objtool: Make instruction::alts " Peter Zijlstra
2023-02-13 11:10 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2023-02-23 8:32 ` tip-bot2 for Peter Zijlstra
2023-02-08 17:18 ` [PATCH 04/10] objtool: Shrink instruction::{type,visited} Peter Zijlstra
2023-02-13 11:10 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2023-02-23 8:32 ` tip-bot2 for Peter Zijlstra
2023-02-08 17:18 ` [PATCH 05/10] objtool: Remove instruction::reloc Peter Zijlstra
2023-02-13 11:10 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2023-02-23 8:32 ` tip-bot2 for Peter Zijlstra
2023-02-08 17:18 ` [PATCH 06/10] objtool: Union instruction::{call_dest,jump_table} Peter Zijlstra
2023-02-13 11:10 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2023-02-23 8:32 ` tip-bot2 for Peter Zijlstra
2023-02-08 17:18 ` [PATCH 07/10] objtool: Fix overlapping alternatives Peter Zijlstra
2023-02-13 11:10 ` tip-bot2 for Peter Zijlstra [this message]
2023-02-23 8:32 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2023-02-08 17:18 ` [PATCH 08/10] x86: Fix FILL_RETURN_BUFFER Peter Zijlstra
2023-02-13 11:10 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2023-02-23 8:32 ` tip-bot2 for Peter Zijlstra
2023-02-08 17:18 ` [PATCH 09/10] objtool: Remove instruction::list Peter Zijlstra
2023-02-13 11:10 ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2023-02-23 8:32 ` tip-bot2 for Peter Zijlstra
2023-02-08 17:18 ` [PATCH 10/10][HACK] objtool: Shrink reloc Peter Zijlstra
2023-02-08 18:35 ` [PATCH 00/10] objtool: Honey, I shrunk the instruction Nathan Chancellor
2023-02-08 20:22 ` Damian Tometzki
2023-02-09 10:22 ` Peter Zijlstra
2023-02-09 10:56 ` Damian Tometzki
2023-02-09 19:57 ` Josh Poimboeuf
2023-02-10 8:59 ` Peter Zijlstra
2023-02-10 13:47 ` [PATCH 00/10] objtool: Honey, I shrunk the instruction^Wreloc Peter Zijlstra
2023-02-10 1:50 ` [PATCH 00/10] objtool: Honey, I shrunk the instruction Thomas Weißschuh
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