From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org, peterz@infradead.org, linux-kernel@vger.kernel.org
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Jason Baron <jbaron@akamai.com>, Nadav Amit <namit@vmware.com>,
Andy Lutomirski <luto@kernel.org>,
Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: [RFC][PATCH 5/8] jump_label, x86: Improve error when we fail expected text
Date: Fri, 28 Jun 2019 12:21:18 +0200 [thread overview]
Message-ID: <20190628103224.716910079@infradead.org> (raw)
In-Reply-To: 20190628102113.360432762@infradead.org
There is only a single usage site left, remove the function and extend
the print to include more information, like the expected text and the
patch type.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/kernel/jump_label.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)
--- a/arch/x86/kernel/jump_label.c
+++ b/arch/x86/kernel/jump_label.c
@@ -24,17 +24,6 @@ union jump_code_union {
} __attribute__((packed));
};
-static void bug_at(unsigned char *ip, int line)
-{
- /*
- * The location is not an op that we were expecting.
- * Something went wrong. Crash the box, as something could be
- * corrupting the kernel.
- */
- pr_crit("jump_label: Fatal kernel bug, unexpected op at %pS [%p] (%5ph) %d\n", ip, ip, ip, line);
- BUG();
-}
-
static void __jump_label_set_jump_code(struct jump_entry *entry,
enum jump_label_type type,
union jump_code_union *code,
@@ -42,6 +31,7 @@ static void __jump_label_set_jump_code(s
{
const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP };
const unsigned char *ideal_nop = ideal_nops[NOP_ATOMIC5];
+ unsigned char *ip = (void *)jump_entry_code(entry);
const void *expect;
int line;
@@ -57,8 +47,16 @@ static void __jump_label_set_jump_code(s
expect = code->code; line = __LINE__;
}
- if (memcmp((void *)jump_entry_code(entry), expect, JUMP_LABEL_NOP_SIZE))
- bug_at((void *)jump_entry_code(entry), line);
+ if (memcmp(ip, expect, JUMP_LABEL_NOP_SIZE)) {
+ /*
+ * The location is not an op that we were expecting.
+ * Something went wrong. Crash the box, as something could be
+ * corrupting the kernel.
+ */
+ pr_crit("jump_label: Fatal kernel bug, unexpected op at %pS [%p] (%5ph != %5ph)) line:%d init:%d type:%d\n",
+ ip, ip, ip, expect, line, init, type);
+ BUG();
+ }
if (type == JUMP_LABEL_NOP)
memcpy(code, ideal_nop, JUMP_LABEL_NOP_SIZE);
next prev parent reply other threads:[~2019-06-28 13:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-28 10:21 [RFC][PATCH 0/8] jump_label, x86: Support variable sized JMP instructions Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 1/8] x86/alternatives: Teach text_poke_bp() to emulate instructions Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 2/8] jump_label, x86: Strip ASM jump_label support Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 3/8] jump_label, x86: Factor out the __jump_table generation Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 4/8] jump_label, x86: Remove init NOP optimization Peter Zijlstra
2019-06-28 10:21 ` Peter Zijlstra [this message]
2019-06-28 10:21 ` [RFC][PATCH 6/8] jump_label, x86: Add variable length patching support Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 7/8] jump_label, x86: Introduce jump_entry_size() Peter Zijlstra
2019-06-28 10:21 ` [RFC][PATCH 8/8] jump_label, x86: Enable JMP8/NOP2 support Peter Zijlstra
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