From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
Randy Dunlap <rdunlap@infradead.org>,
Arnd Bergmann <arnd@arndb.de>, Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Greg KH <gregkh@linuxfoundation.org>,
David Laight <David.Laight@ACULAB.COM>,
damian <damian.tometzki@icloud.com>
Subject: [PATCH v1.2 3/3] objtool: Support GCC 8 switch tables
Date: Thu, 10 May 2018 17:45:16 -0500 [thread overview]
Message-ID: <20180510224516.s7qcjvbolwxkvzqd@treble> (raw)
In-Reply-To: <20180510124424.uauk7p4uzsfon4hs@treble>
Add some additional checks to the switch jump table logic. This fixes
the following warnings with GCC 8:
drivers/block/virtio_blk.o: warning: objtool: virtio_queue_rq()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+72
net/ipv6/icmp.o: warning: objtool: icmpv6_rcv()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+64
drivers/usb/core/quirks.o: warning: objtool: quirks_param_set()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+48
drivers/mtd/nand/raw/nand_hynix.o: warning: objtool: hynix_nand_decode_id()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+24
drivers/mtd/nand/raw/nand_samsung.o: warning: objtool: samsung_nand_decode_id()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+32
drivers/gpu/drm/nouveau/nvkm/subdev/top/gk104.o: warning: objtool: gk104_top_oneinit()+0x0: stack state mismatch: cfa1=7+8 cfa2=7+64
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
v1.2: replaced 'sizeof(long)' with '8' to fix cross-compilation of the
64-bit target on a 32-bit host
tools/objtool/check.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 14daf6a27d9f..9bb04fddd3c8 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -810,17 +810,28 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,
struct rela *rela = table;
struct instruction *alt_insn;
struct alternative *alt;
+ struct symbol *pfunc = insn->func->pfunc;
+ unsigned int prev_offset = 0;
list_for_each_entry_from(rela, &file->rodata->rela->rela_list, list) {
if (rela == next_table)
break;
+ /* Make sure the switch table entries are consecutive: */
+ if (prev_offset && rela->offset != prev_offset + 8)
+ break;
+
+ /* Detect function pointers from contiguous objects: */
+ if (rela->sym->sec == pfunc->sec &&
+ rela->addend == pfunc->offset)
+ break;
+
alt_insn = find_insn(file, rela->sym->sec, rela->addend);
if (!alt_insn)
break;
/* Make sure the jmp dest is in the function or subfunction: */
- if (alt_insn->func->pfunc != insn->func->pfunc)
+ if (alt_insn->func->pfunc != pfunc)
break;
alt = malloc(sizeof(*alt));
@@ -831,6 +842,13 @@ static int add_switch_table(struct objtool_file *file, struct instruction *insn,
alt->insn = alt_insn;
list_add_tail(&alt->list, &insn->alts);
+ prev_offset = rela->offset;
+ }
+
+ if (!prev_offset) {
+ WARN_FUNC("can't find switch jump table",
+ insn->sec, insn->offset);
+ return -1;
}
return 0;
@@ -887,7 +905,9 @@ static struct rela *find_switch_table(struct objtool_file *file,
struct instruction *orig_insn = insn;
text_rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len);
- if (text_rela && text_rela->sym == file->rodata->sym) {
+ if (text_rela && text_rela->sym == file->rodata->sym &&
+ !find_symbol_containing(file->rodata, text_rela->addend)) {
+
/* case 1 */
rodata_rela = find_rela_by_dest(file->rodata,
text_rela->addend);
--
2.17.0
next prev parent reply other threads:[~2018-05-10 22:45 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-10 3:39 [PATCH 0/3] objtool: GCC 8 support Josh Poimboeuf
2018-05-10 3:39 ` [PATCH 1/3] objtool: Fix "noreturn" detection for recursive sibling calls Josh Poimboeuf
2018-05-14 12:37 ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2018-05-10 3:39 ` [PATCH 2/3] objtool: Support GCC 8 cold subfunctions Josh Poimboeuf
2018-05-14 12:37 ` [tip:core/urgent] objtool: Support GCC 8's " tip-bot for Josh Poimboeuf
2018-05-10 3:39 ` [PATCH 3/3] objtool: Support GCC 8 switch tables Josh Poimboeuf
2018-05-10 8:41 ` Peter Zijlstra
2018-05-10 12:44 ` [PATCH v1.1 " Josh Poimboeuf
2018-05-10 14:07 ` Peter Zijlstra
2018-05-10 22:45 ` Josh Poimboeuf [this message]
2018-05-10 22:48 ` [PATCH v1.3 " Josh Poimboeuf
2018-05-14 12:38 ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
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