From: Steven Rostedt <rostedt@goodmis.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, tglx@linutronix.de,
peterz@infradead.org, fweisbec@gmail.com,
torvalds@linux-foundation.org, arjan@infradead.org,
rusty@rustcorp.com.au, mathieu.desnoyers@polymtl.ca,
hpa@zytor.com, srostedt@redhat.com
Subject: [PATCH][git pull] update to tip/tracing/ftrace
Date: Thu, 19 Feb 2009 21:05:46 -0500 (EST) [thread overview]
Message-ID: <alpine.DEB.1.10.0902192104410.31658@gandalf.stny.rr.com> (raw)
In-Reply-To: <alpine.DEB.1.10.0902192041200.31658@gandalf.stny.rr.com>
Ingo,
Please pull the latest tip/tracing/ftrace tree, which can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
tip/tracing/ftrace
Steven Rostedt (1):
ftrace, x86: do not depend on system state for kernel text info
----
arch/x86/kernel/ftrace.c | 8 --------
arch/x86/mm/init_32.c | 10 ++++++++++
arch/x86/mm/init_64.c | 10 ++++++++++
3 files changed, 20 insertions(+), 8 deletions(-)
---------------------------
commit 5d8ecb6568c598de6b6e678329e2ec0703a821f7
Author: Steven Rostedt <srostedt@redhat.com>
Date: Thu Feb 19 20:51:45 2009 -0500
ftrace, x86: do not depend on system state for kernel text info
Andrew Morton pointed out that using SYSTEM_STATE is a bad idea
since there is no guarantee to what its state will actually be.
Instead, I moved the check into the set_kernel_text_* functions
themselves, and use a local variable to determine when it is
OK to change the kernel text RW permissions.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 26b64a8..4f4e82c 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -28,20 +28,12 @@
int ftrace_arch_modify_prepare(void)
{
- /* at boot up, we are still writable */
- if (system_state != SYSTEM_RUNNING)
- return 0;
-
set_kernel_text_rw();
return 0;
}
int ftrace_arch_modify_post_process(void)
{
- /* at boot up, we are still writable */
- if (system_state != SYSTEM_RUNNING)
- return 0;
-
set_kernel_text_ro();
return 0;
}
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index bcd7f00..9ca4c57 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -1155,12 +1155,17 @@ static noinline int do_test_wp_bit(void)
const int rodata_test_data = 0xC3;
EXPORT_SYMBOL_GPL(rodata_test_data);
+static int kernel_set_to_readonly;
+
/* used by ftrace */
void set_kernel_text_rw(void)
{
unsigned long start = PFN_ALIGN(_text);
unsigned long size = PFN_ALIGN(_etext) - start;
+ if (!kernel_set_to_readonly)
+ return;
+
printk(KERN_INFO "Set kernel text: %lx - %lx for read write\n",
start, start+size);
@@ -1173,6 +1178,9 @@ void set_kernel_text_ro(void)
unsigned long start = PFN_ALIGN(_text);
unsigned long size = PFN_ALIGN(_etext) - start;
+ if (!kernel_set_to_readonly)
+ return;
+
printk(KERN_INFO "Set kernel text: %lx - %lx for read only\n",
start, start+size);
@@ -1188,6 +1196,8 @@ void mark_rodata_ro(void)
printk(KERN_INFO "Write protecting the kernel text: %luk\n",
size >> 10);
+ kernel_set_to_readonly = 1;
+
#ifdef CONFIG_CPA_DEBUG
printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
start, start+size);
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 8c1b5ee..c204433 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -986,12 +986,17 @@ void free_initmem(void)
const int rodata_test_data = 0xC3;
EXPORT_SYMBOL_GPL(rodata_test_data);
+static int kernel_set_to_readonly;
+
/* used by ftrace */
void set_kernel_text_rw(void)
{
unsigned long start = PFN_ALIGN(_stext);
unsigned long end = PFN_ALIGN(__start_rodata);
+ if (!kernel_set_to_readonly)
+ return;
+
printk(KERN_INFO "Set kernel text: %lx - %lx for read write\n",
start, end);
@@ -1004,6 +1009,9 @@ void set_kernel_text_ro(void)
unsigned long start = PFN_ALIGN(_stext);
unsigned long end = PFN_ALIGN(__start_rodata);
+ if (!kernel_set_to_readonly)
+ return;
+
printk(KERN_INFO "Set kernel text: %lx - %lx for read only\n",
start, end);
@@ -1020,6 +1028,8 @@ void mark_rodata_ro(void)
(end - start) >> 10);
set_memory_ro(start, (end - start) >> PAGE_SHIFT);
+ kernel_set_to_readonly = 1;
+
/*
* The rodata section (but not the kernel text!) should also be
* not-executable.
next prev parent reply other threads:[~2009-02-20 2:05 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-20 1:13 [git pull] changes for tip, and a nasty x86 page table bug Steven Rostedt
2009-02-20 1:13 ` [PATCH 1/6] x86: check PMD in spurious_fault handler Steven Rostedt
2009-02-20 1:13 ` [PATCH 2/6] x86: keep pmd rw bit set when creating 4K level pages Steven Rostedt
2009-02-20 1:13 ` [PATCH 3/6] ftrace: allow archs to preform pre and post process for code modification Steven Rostedt
2009-02-20 1:13 ` [PATCH 4/6] ftrace, x86: make kernel text writable only for conversions Steven Rostedt
2009-02-20 1:32 ` Andrew Morton
2009-02-20 1:44 ` Steven Rostedt
2009-02-20 2:05 ` Steven Rostedt [this message]
2009-02-22 17:50 ` Andi Kleen
2009-02-22 22:53 ` Steven Rostedt
2009-02-23 0:29 ` Andi Kleen
2009-02-23 2:33 ` Mathieu Desnoyers
2009-02-23 4:29 ` Steven Rostedt
2009-02-23 4:53 ` Mathieu Desnoyers
2009-02-23 14:48 ` Steven Rostedt
2009-02-23 15:42 ` Mathieu Desnoyers
2009-02-23 15:51 ` Steven Rostedt
2009-02-23 15:55 ` Steven Rostedt
2009-02-23 16:13 ` Mathieu Desnoyers
2009-02-23 16:48 ` Steven Rostedt
2009-02-23 17:31 ` Mathieu Desnoyers
2009-02-23 18:17 ` Steven Rostedt
2009-02-23 18:34 ` Mathieu Desnoyers
2009-02-27 17:52 ` Masami Hiramatsu
2009-02-27 18:07 ` Mathieu Desnoyers
2009-02-27 18:34 ` Masami Hiramatsu
2009-02-27 18:53 ` Mathieu Desnoyers
2009-02-27 20:57 ` Masami Hiramatsu
2009-03-02 17:01 ` [RFC][PATCH] x86: make text_poke() atomic Masami Hiramatsu
2009-03-02 17:19 ` Mathieu Desnoyers
2009-03-02 22:15 ` Masami Hiramatsu
2009-03-02 22:22 ` Ingo Molnar
2009-03-02 22:55 ` Masami Hiramatsu
2009-03-02 23:09 ` Ingo Molnar
2009-03-02 23:38 ` Masami Hiramatsu
2009-03-02 23:49 ` Ingo Molnar
2009-03-03 0:00 ` Mathieu Desnoyers
2009-03-03 0:00 ` [PATCH] Text Edit Lock - Architecture Independent Code Mathieu Desnoyers
2009-03-03 0:32 ` Ingo Molnar
2009-03-03 0:39 ` Mathieu Desnoyers
2009-03-03 1:30 ` [PATCH] Text Edit Lock - Architecture Independent Code (v2) Mathieu Desnoyers
2009-03-03 1:31 ` [PATCH] Text Edit Lock - kprobes architecture independent support (v2) Mathieu Desnoyers
2009-03-03 9:27 ` Ingo Molnar
2009-03-03 12:06 ` Ananth N Mavinakayanahalli
2009-03-03 14:28 ` Mathieu Desnoyers
2009-03-03 14:33 ` [PATCH] Text Edit Lock - kprobes architecture independent support (v3) Mathieu Desnoyers
2009-03-03 14:53 ` [PATCH] Text Edit Lock - kprobes architecture independent support (v2) Ingo Molnar
2009-03-03 0:01 ` [PATCH] Text Edit Lock - kprobes architecture independent support Mathieu Desnoyers
2009-03-03 0:10 ` Masami Hiramatsu
2009-03-03 0:05 ` [RFC][PATCH] x86: make text_poke() atomic Masami Hiramatsu
2009-03-03 0:22 ` Ingo Molnar
2009-03-03 0:31 ` Masami Hiramatsu
2009-03-03 16:31 ` [PATCH] x86: make text_poke() atomic using fixmap Masami Hiramatsu
2009-03-03 17:08 ` Mathieu Desnoyers
2009-03-05 10:38 ` Ingo Molnar
2009-03-06 14:06 ` Ingo Molnar
2009-03-06 14:49 ` Masami Hiramatsu
2009-03-02 18:28 ` [RFC][PATCH] x86: make text_poke() atomic Arjan van de Ven
2009-03-02 18:36 ` Mathieu Desnoyers
2009-03-02 18:55 ` Arjan van de Ven
2009-03-02 19:13 ` Masami Hiramatsu
2009-03-02 19:23 ` H. Peter Anvin
2009-03-02 19:47 ` Mathieu Desnoyers
2009-03-02 18:42 ` Linus Torvalds
2009-03-03 4:54 ` Nick Piggin
2009-02-23 18:23 ` [PATCH 4/6] ftrace, x86: make kernel text writable only for conversions Steven Rostedt
2009-02-23 9:02 ` Ingo Molnar
2009-02-27 21:08 ` Pavel Machek
2009-02-28 16:56 ` Andi Kleen
2009-02-28 22:08 ` Pavel Machek
[not found] ` <87wsba1a9f.fsf@basil.nowhere.org>
2009-02-28 22:19 ` Pavel Machek
2009-02-28 23:52 ` Andi Kleen
2009-02-20 1:13 ` [PATCH 5/6] ftrace: immediately stop code modification if failure is detected Steven Rostedt
2009-02-20 1:13 ` [PATCH 6/6] ftrace: break out modify loop immediately on detection of error Steven Rostedt
2009-02-20 2:00 ` [git pull] changes for tip, and a nasty x86 page table bug Linus Torvalds
2009-02-20 2:08 ` Steven Rostedt
2009-02-20 3:44 ` Linus Torvalds
2009-02-20 4:00 ` Steven Rostedt
2009-02-20 4:17 ` Linus Torvalds
2009-02-20 4:34 ` Steven Rostedt
2009-02-20 5:02 ` Huang Ying
2009-02-20 7:29 ` [PATCH] x86: use the right protections for split-up pagetables Ingo Molnar
2009-02-20 7:39 ` [PATCH, v2] " Ingo Molnar
2009-02-20 8:02 ` Ingo Molnar
2009-02-20 10:24 ` Ingo Molnar
2009-02-20 13:57 ` [PATCH] " Steven Rostedt
2009-02-20 15:40 ` Linus Torvalds
2009-02-20 16:59 ` Ingo Molnar
2009-02-20 18:33 ` H. Peter Anvin
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