diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2025-05-03 16:38:50 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-05-04 10:29:25 +0200 |
| commit | 2d299e3d773d519ee93e5aaa3ffddd4a6276b005 (patch) | |
| tree | bb56219a4c46774ffce8103ba0bae4f06864f7b7 | |
| parent | 8e269c030ecafbfebf4f55e24fb336fd7b489708 (diff) | |
x86/fpu: Always use memcpy_and_pad() in arch_dup_task_struct()
It makes no sense to copy the bytes after sizeof(struct task_struct),
FPU state will be initialized in fpu_clone().
A plain memcpy(dst, src, sizeof(struct task_struct)) should work too,
but "_and_pad" looks safer.
[ mingo: Simplify it a bit more. ]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S . Bae <chang.seok.bae@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250503143850.GA8997@redhat.com
| -rw-r--r-- | arch/x86/kernel/process.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 7a1bfb61d86f..9e6180777565 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -93,11 +93,8 @@ EXPORT_PER_CPU_SYMBOL_GPL(__tss_limit_invalid); */ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { - /* init_task is not dynamically sized (incomplete FPU state) */ - if (unlikely(src == &init_task)) - memcpy_and_pad(dst, arch_task_struct_size, src, sizeof(init_task), 0); - else - memcpy(dst, src, arch_task_struct_size); + /* fpu_clone() will initialize the "dst_fpu" memory */ + memcpy_and_pad(dst, arch_task_struct_size, src, sizeof(*dst), 0); #ifdef CONFIG_VM86 dst->thread.vm86 = NULL; |