diff options
| author | Vegard Nossum <vegard.nossum@oracle.com> | 2023-12-19 16:12:00 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-12-20 10:57:51 +0100 |
| commit | bc90aefa99f74452d549d503a3f1cbf3adc9c6bb (patch) | |
| tree | bec0e959b88282d31132cec1ed2154921815a725 | |
| parent | 3b184b71dfcb156e08246f8fbe0cd088c6a6efed (diff) | |
x86/asm: Add DB flag to 32-bit percpu GDT entry
The D/B size flag for the 32-bit percpu GDT entry was not set.
The Intel manual (vol 3, section 3.4.5) only specifies the meaning of
this flag for three cases:
1) code segments used for %cs -- doesn't apply here
2) stack segments used for %ss -- doesn't apply
3) expand-down data segments -- but we don't have the expand-down flag
set, so it also doesn't apply here
The flag likely doesn't do anything here, although the manual does also
say: "This flag should always be set to 1 for 32-bit code and data
segments [...]" so we should probably do it anyway.
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20231219151200.2878271-6-vegard.nossum@oracle.com
| -rw-r--r-- | arch/x86/kernel/setup_percpu.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index f2583de97a64..b30d6e180df7 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -106,7 +106,7 @@ void __init pcpu_populate_pte(unsigned long addr) static inline void setup_percpu_segment(int cpu) { #ifdef CONFIG_X86_32 - struct desc_struct d = GDT_ENTRY_INIT(DESC_DATA32 & ~_DESC_DB, + struct desc_struct d = GDT_ENTRY_INIT(DESC_DATA32, per_cpu_offset(cpu), 0xFFFFF); write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_PERCPU, &d, DESCTYPE_S); |