diff options
| author | Jiri Kosina <jkosina@suse.cz> | 2018-01-03 15:20:04 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-01-09 00:35:20 +0000 |
| commit | 8eb0a71f15bd4e5b798c3fbe2f9932a69318a437 (patch) | |
| tree | 40b53636a396ad8f820c1c8d1ca7a0aa02a8a998 | |
| parent | 6ea3e97f1db2adeb219fcdc451ab6ec85f6eb0ad (diff) | |
kaiser: x86: Fix NMI handling
On Mon, 4 Dec 2017, Hugh Dickins wrote:
> kaiser-3.18.72.tar
Hi Hugh,
this hunk from 0024-kaiser-merged-update.patch:
- SWITCH_KERNEL_CR3_NO_STACK
+ /*
+ * percpu variables are mapped with user CR3, so no need
+ * to switch CR3 here.
+ */
cld
movq %rsp, %rdx
movq PER_CPU_VAR(kernel_stack), %rsp
is problematic, as the patchset actually never user-maps kernel_stack
percpu variable, and therefore crashes on NMIs.
The patch below is needed to make NMIs work properly.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index f5232878632d..274f5a7b27e7 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1180,7 +1180,7 @@ static __init int setup_disablecpuid(char *arg) } __setup("clearcpuid=", setup_disablecpuid); -DEFINE_PER_CPU(unsigned long, kernel_stack) = +DEFINE_PER_CPU_USER_MAPPED(unsigned long, kernel_stack) = (unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE; EXPORT_PER_CPU_SYMBOL(kernel_stack); |