[lkml]   [2019]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 5/9] arm64: correctly check for ktrheads
Since commit:

6eb6c80187c55b7f ("arm64: kernel thread don't need to save fpsimd context.")

... we skip saving the fpsimd state for kernel threads in
arch_dup_task_struct(). We determine whether current is a kthread by
looking at current->mm.

In general, a non-NULL current->mm doesn't imply that current is a
kthread, as kthreads can install an mm via use_mm(), and so it's
preferable to use is_kthread() to determine whether a thread is a

For consistency, let's use is_kthread() here.

Signed-off-by: Mark Rutland <>
Cc: Catalin Marinas <>
Cc: Ingo Molnar <>
Cc: Peter Zijlstra <>
Cc: Will Deacon <>
arch/arm64/kernel/process.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 288012687c29..82b0a7a257cd 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -335,7 +335,7 @@ void arch_release_task_struct(struct task_struct *tsk)
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
- if (current->mm)
+ if (!is_kthread(current))
*dst = *src;

 \ /
  Last update: 2019-08-14 12:43    [W:0.110 / U:135.148 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site