diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-22 13:09:51 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-22 13:09:51 -0800 |
| commit | ac630dd98a47b60b27d716758d5f4276cb974662 (patch) | |
| tree | 55e8d5f26c99523c6ebaa8e5059cf678c848fb25 | |
| parent | 2ef14f465b9e096531343f5b734cffc5f759f4a6 (diff) | |
x86-64: don't set the early IDT to point directly to 'early_idt_handler'
The code requires the use of the proper per-exception-vector stub
functions (set up as the early_idt_handlers[] array - note the 's') that
make sure to set up the error vector number. This is true regardless of
whether CONFIG_EARLY_PRINTK is set or not.
Why? The stack offset for the comparison of __KERNEL_CS won't be right
otherwise, nor will the new check (from commit 8170e6bed465: "x86,
64bit: Use a #PF handler to materialize early mappings on demand") for
the page fault exception vector.
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/x86/include/asm/proto.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/head64.c | 7 | ||||
| -rw-r--r-- | arch/x86/kernel/head_64.S | 2 |
3 files changed, 3 insertions, 8 deletions
diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h index 6f414ed8862..6fd3fd76979 100644 --- a/arch/x86/include/asm/proto.h +++ b/arch/x86/include/asm/proto.h @@ -5,8 +5,6 @@ /* misc architecture specific prototypes */ -void early_idt_handler(void); - void system_call(void); void syscall_init(void); diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 57334f4cd3a..2590025e52c 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -159,13 +159,8 @@ void __init x86_64_start_kernel(char * real_mode_data) /* clear bss before set_intr_gate with early_idt_handler */ clear_bss(); - for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) { -#ifdef CONFIG_EARLY_PRINTK + for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) set_intr_gate(i, &early_idt_handlers[i]); -#else - set_intr_gate(i, early_idt_handler); -#endif - } load_idt((const struct desc_ptr *)&idt_descr); copy_bootdata(__va(real_mode_data)); diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index d94f6d68be2..b7de3b25adb 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -336,6 +336,7 @@ early_idt_handlers: i = i + 1 .endr +/* This is global to keep gas from relaxing the jumps */ ENTRY(early_idt_handler) cld @@ -404,6 +405,7 @@ ENTRY(early_idt_handler) addq $16,%rsp # drop vector number and error code decl early_recursion_flag(%rip) INTERRUPT_RETURN +ENDPROC(early_idt_handler) __INITDATA |