From: tip-bot for Masami Hiramatsu <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: hpa@zytor.com, tglx@linutronix.de, peterz@infradead.org,
torvalds@linux-foundation.org, jpoimboe@redhat.com,
brgerst@gmail.com, ananth@linux.vnet.ibm.com,
linux-kernel@vger.kernel.org, dvlasenk@redhat.com,
xiaolong.ye@intel.com, mhiramat@kernel.org, mingo@kernel.org,
bp@alien8.de, anil.s.keshavamurthy@intel.com,
davem@davemloft.net, aryabinin@virtuozzo.com
Subject: [tip:perf/core] kprobes/x86: Set kprobes pages read-only
Date: Wed, 12 Apr 2017 00:34:35 -0700 [thread overview]
Message-ID: <tip-d0381c81c2f782fa2131178d11e0cfb23d50d631@git.kernel.org> (raw)
In-Reply-To: <149076375592.22469.14174394514338612247.stgit@devbox>
Commit-ID: d0381c81c2f782fa2131178d11e0cfb23d50d631
Gitweb: http://git.kernel.org/tip/d0381c81c2f782fa2131178d11e0cfb23d50d631
Author: Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Wed, 29 Mar 2017 14:02:46 +0900
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 12 Apr 2017 09:23:46 +0200
kprobes/x86: Set kprobes pages read-only
Set the pages which is used for kprobes' singlestep buffer
and optprobe's trampoline instruction buffer to readonly.
This can prevent unexpected (or unintended) instruction
modification.
This also passes rodata_test as below.
Without this patch, rodata_test shows a warning:
WARNING: CPU: 0 PID: 1 at arch/x86/mm/dump_pagetables.c:235 note_page+0x7a9/0xa20
x86/mm: Found insecure W+X mapping at address ffffffffa0000000/0xffffffffa0000000
With this fix, no W+X pages are found:
x86/mm: Checked W+X mappings: passed, no W+X pages found.
rodata_test: all tests were successful
Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David S . Miller <davem@davemloft.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ye Xiaolong <xiaolong.ye@intel.com>
Link: http://lkml.kernel.org/r/149076375592.22469.14174394514338612247.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/kprobes/core.c | 4 ++++
arch/x86/kernel/kprobes/opt.c | 3 +++
2 files changed, 7 insertions(+)
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 3f084a0..0dc24e6 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -419,6 +419,8 @@ static int arch_copy_kprobe(struct kprobe *p)
{
int len;
+ set_memory_rw((unsigned long)p->ainsn.insn & PAGE_MASK, 1);
+
/* Copy an instruction with recovering if other optprobe modifies it.*/
len = __copy_instruction(p->ainsn.insn, p->addr);
if (!len)
@@ -430,6 +432,8 @@ static int arch_copy_kprobe(struct kprobe *p)
*/
prepare_boost(p, len);
+ set_memory_ro((unsigned long)p->ainsn.insn & PAGE_MASK, 1);
+
/* Check whether the instruction modifies Interrupt Flag or not */
p->ainsn.if_modifier = is_IF_modifier(p->ainsn.insn);
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 3e7c6e5..b121037 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -350,6 +350,7 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op,
}
buf = (u8 *)op->optinsn.insn;
+ set_memory_rw((unsigned long)buf & PAGE_MASK, 1);
/* Copy instructions into the out-of-line buffer */
ret = copy_optimized_instructions(buf + TMPL_END_IDX, op->kp.addr);
@@ -372,6 +373,8 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op,
synthesize_reljump(buf + TMPL_END_IDX + op->optinsn.size,
(u8 *)op->kp.addr + op->optinsn.size);
+ set_memory_ro((unsigned long)buf & PAGE_MASK, 1);
+
flush_icache_range((unsigned long) buf,
(unsigned long) buf + TMPL_END_IDX +
op->optinsn.size + RELATIVEJUMP_SIZE);
next prev parent reply other threads:[~2017-04-12 7:40 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-29 4:55 [RFC PATCH tip/master V3 0/8] kprobes/x86: Make kprobes instruction buffers read-only Masami Hiramatsu
2017-03-29 4:56 ` [RFC PATCH tip/master V3 1/8] kprobes/x86: Fix not to boost call far instruction Masami Hiramatsu
2017-04-12 7:32 ` [tip:perf/core] kprobes/x86: Fix kprobe-booster not to boost far call instructions tip-bot for Masami Hiramatsu
2017-03-29 4:58 ` [RFC PATCH tip/master V3 2/8] kprobes/x86: Fix the description of __copy_instruction() Masami Hiramatsu
2017-04-12 7:32 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-03-29 4:59 ` [RFC PATCH tip/master V3 3/8] kprobes/x86: Use instruction decoder for booster Masami Hiramatsu
2017-04-12 7:33 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-03-29 5:00 ` [RFC PATCH tip/master V3 4/8] kprobes/x86: Do not modify singlestep buffer while resuming Masami Hiramatsu
2017-04-12 7:33 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-03-29 5:01 ` [RFC PATCH tip/master V3 5/8] kprobes/x86: Make boostable flag boolean Masami Hiramatsu
2017-04-12 7:34 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-03-29 5:02 ` [RFC PATCH tip/master V3 6/8] kprobes/x86: Set kprobes pages readonly Masami Hiramatsu
2017-04-12 7:34 ` tip-bot for Masami Hiramatsu [this message]
2017-03-29 5:03 ` [RFC PATCH tip/master V3 7/8] kprobes/x86: Use probe_kernel_read instead of memcpy Masami Hiramatsu
2017-04-12 7:35 ` [tip:perf/core] kprobes/x86: Use probe_kernel_read() instead of memcpy() tip-bot for Masami Hiramatsu
2017-03-29 5:05 ` [RFC PATCH tip/master V3 8/8] kprobes/x86: Consolidate insn decoder users for copying code Masami Hiramatsu
2017-04-12 7:35 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-04-11 5:44 ` [RFC PATCH tip/master V3 0/8] kprobes/x86: Make kprobes instruction buffers read-only Masami Hiramatsu
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