From: "chengjian (D)" <cj.chengjian@huawei.com>
To: <andrew.murray@arm.com>, <bristot@redhat.com>,
<jakub.kicinski@netronome.com>, Kees Cook <keescook@chromium.org>
Cc: "x86@kernel.org" <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
"Xiexiuqi (Xie XiuQi)" <xiexiuqi@huawei.com>,
Li Bin <huawei.libin@huawei.com>, <bobo.shaobowang@huawei.com>,
"chengjian (D)" <cj.chengjian@huawei.com>
Subject: Why is text_mutex used in jump_label_transform for x86_64
Date: Thu, 19 Mar 2020 21:49:04 +0800 [thread overview]
Message-ID: <f7f686f2-4f28-1763-dd19-43eff6a5a8f2@huawei.com> (raw)
Hi,everyone
I'm sorry to disturb you. I have a problem about jump_label, and a bit
confused about the code
I noticed that text_mutex is used in this function under x86_64
architecture,
but other architectures do not.
in arch/x86/kernel/jump_label.c
static void __ref jump_label_transform(struct jump_entry *entry,
enum jump_label_type type,
int init)
{
mutex_lock(&text_mutex);
__jump_label_transform(entry, type, init);
mutex_unlock(&text_mutex);
in arch/arm64/kernel/jump_label.c
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
void *addr = (void *)jump_entry_code(entry);
u32 insn;
if (type == JUMP_LABEL_JMP) {
insn =
aarch64_insn_gen_branch_imm(jump_entry_code(entry),
jump_entry_target(entry),
AARCH64_INSN_BRANCH_NOLINK);
} else {
insn = aarch64_insn_gen_nop();
}
aarch64_insn_patch_text_nosync(addr, insn);
}
Is there anything wrong with x86
or
is this missing for other architectures?
Thanks
---- Cheng Jian
next reply other threads:[~2020-03-19 13:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-19 13:49 chengjian (D) [this message]
2020-03-20 10:27 ` Why is text_mutex used in jump_label_transform for x86_64 Peter Zijlstra
2020-04-06 8:39 ` chengjian (D)
2020-04-06 9:15 ` Peter Zijlstra
2020-04-06 14:10 ` Will Deacon
2020-04-08 1:17 ` chengjian (D)
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