* Re: [PATCH] x86/ldt: Initialize the context lock for init_mm
2019-07-01 17:33 [PATCH] x86/ldt: Initialize the context lock for init_mm Sebastian Andrzej Siewior
@ 2019-07-01 17:49 ` Nadav Amit
2019-07-03 8:28 ` [tip:x86/urgent] " tip-bot for Sebastian Andrzej Siewior
2019-07-09 12:02 ` tip-bot for Sebastian Andrzej Siewior
2 siblings, 0 replies; 4+ messages in thread
From: Nadav Amit @ 2019-07-01 17:49 UTC (permalink / raw)
To: Sebastian Andrzej Siewior
Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Peter Zijlstra,
Andy Lutomirski
> On Jul 1, 2019, at 10:33 AM, Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:
>
> The mutex mm->context->lock for init_mm is not initialized for init_mm.
> This wasn't a problem because it remained unused. This changed however
> since commit
> 4fc19708b165c ("x86/alternatives: Initialize temporary mm for patching")
>
> Initialize the mutex for init_mm.
>
> Fixes: 4fc19708b165c ("x86/alternatives: Initialize temporary mm for patching")
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>
> The rwsem `ldt_usr_sem' is also not initialized for init_mm. No idea if
> we want this.
I cannot see why not (but it would need to depend on CONFIG_MODIFY_LDT_SYSCALL)
>
> arch/x86/include/asm/mmu.h | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h
> index 5ff3e8af2c205..e78c7db878018 100644
> --- a/arch/x86/include/asm/mmu.h
> +++ b/arch/x86/include/asm/mmu.h
> @@ -59,6 +59,7 @@ typedef struct {
> #define INIT_MM_CONTEXT(mm) \
> .context = { \
> .ctx_id = 1, \
> + .lock = __MUTEX_INITIALIZER(mm.context.lock), \
Sorry for my mistake. Thanks for fixing it up. I find it useful to know how
the problem was found or what the impact was - helps me sometimes to avoid
causing similar bugs in the future.
Reviewed-by: Nadav Amit <namit@vmware.com>
^ permalink raw reply [flat|nested] 4+ messages in thread* [tip:x86/urgent] x86/ldt: Initialize the context lock for init_mm
2019-07-01 17:33 [PATCH] x86/ldt: Initialize the context lock for init_mm Sebastian Andrzej Siewior
2019-07-01 17:49 ` Nadav Amit
@ 2019-07-03 8:28 ` tip-bot for Sebastian Andrzej Siewior
2019-07-09 12:02 ` tip-bot for Sebastian Andrzej Siewior
2 siblings, 0 replies; 4+ messages in thread
From: tip-bot for Sebastian Andrzej Siewior @ 2019-07-03 8:28 UTC (permalink / raw)
To: linux-tip-commits
Cc: namit, mingo, tglx, peterz, hpa, bigeasy, luto, linux-kernel
Commit-ID: 32232b350d7cd93cdc65fe5a453e6a40b539e9f9
Gitweb: https://git.kernel.org/tip/32232b350d7cd93cdc65fe5a453e6a40b539e9f9
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate: Mon, 1 Jul 2019 19:33:54 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 3 Jul 2019 10:25:04 +0200
x86/ldt: Initialize the context lock for init_mm
The mutex mm->context->lock for init_mm is not initialized for init_mm.
This wasn't a problem because it remained unused. This changed however
since commit
4fc19708b165c ("x86/alternatives: Initialize temporary mm for patching")
Initialize the mutex for init_mm.
Fixes: 4fc19708b165c ("x86/alternatives: Initialize temporary mm for patching")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20190701173354.2pe62hhliok2afea@linutronix.de
---
arch/x86/include/asm/mmu.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h
index 5ff3e8af2c20..e78c7db87801 100644
--- a/arch/x86/include/asm/mmu.h
+++ b/arch/x86/include/asm/mmu.h
@@ -59,6 +59,7 @@ typedef struct {
#define INIT_MM_CONTEXT(mm) \
.context = { \
.ctx_id = 1, \
+ .lock = __MUTEX_INITIALIZER(mm.context.lock), \
}
void leave_mm(int cpu);
^ permalink raw reply related [flat|nested] 4+ messages in thread* [tip:x86/urgent] x86/ldt: Initialize the context lock for init_mm
2019-07-01 17:33 [PATCH] x86/ldt: Initialize the context lock for init_mm Sebastian Andrzej Siewior
2019-07-01 17:49 ` Nadav Amit
2019-07-03 8:28 ` [tip:x86/urgent] " tip-bot for Sebastian Andrzej Siewior
@ 2019-07-09 12:02 ` tip-bot for Sebastian Andrzej Siewior
2 siblings, 0 replies; 4+ messages in thread
From: tip-bot for Sebastian Andrzej Siewior @ 2019-07-09 12:02 UTC (permalink / raw)
To: linux-tip-commits
Cc: hpa, peterz, luto, linux-kernel, mingo, tglx, bigeasy, namit
Commit-ID: 39ca5fb4920a96eeab478be2cfa6a2369fef6b02
Gitweb: https://git.kernel.org/tip/39ca5fb4920a96eeab478be2cfa6a2369fef6b02
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate: Mon, 1 Jul 2019 19:33:54 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 9 Jul 2019 13:57:27 +0200
x86/ldt: Initialize the context lock for init_mm
The mutex mm->context->lock for init_mm is not initialized for init_mm.
This wasn't a problem because it remained unused. This changed however
since commit
4fc19708b165c ("x86/alternatives: Initialize temporary mm for patching")
Initialize the mutex for init_mm.
Fixes: 4fc19708b165c ("x86/alternatives: Initialize temporary mm for patching")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20190701173354.2pe62hhliok2afea@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/mmu.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h
index 5ff3e8af2c20..e78c7db87801 100644
--- a/arch/x86/include/asm/mmu.h
+++ b/arch/x86/include/asm/mmu.h
@@ -59,6 +59,7 @@ typedef struct {
#define INIT_MM_CONTEXT(mm) \
.context = { \
.ctx_id = 1, \
+ .lock = __MUTEX_INITIALIZER(mm.context.lock), \
}
void leave_mm(int cpu);
^ permalink raw reply related [flat|nested] 4+ messages in thread