From: "H. Peter Anvin (Intel)" <[email protected]>
There is no reason to specify any specific address to
idt_invalidate(). It looks mostly like an artifact of unifying code
done differently by accident. The most "sensible" address to set here
is a NULL pointer - virtual address zero, just as a visual marker.
This also makes it possible to mark the struct desc_ptr in
idt_invalidate() as static const.
Signed-off-by: H. Peter Anvin (Intel) <[email protected]>
---
arch/x86/include/asm/desc.h | 2 +-
arch/x86/kernel/idt.c | 5 ++---
arch/x86/kernel/machine_kexec_32.c | 2 +-
arch/x86/kernel/reboot.c | 2 +-
4 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index 476082a83d1c..b8429ae50b71 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -427,6 +427,6 @@ static inline void idt_setup_early_pf(void) { }
static inline void idt_setup_ist_traps(void) { }
#endif
-extern void idt_invalidate(void *addr);
+extern void idt_invalidate(void);
#endif /* _ASM_X86_DESC_H */
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index d552f177eca0..2779f5226dc2 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -331,11 +331,10 @@ void __init idt_setup_early_handler(void)
/**
* idt_invalidate - Invalidate interrupt descriptor table
- * @addr: The virtual address of the 'invalid' IDT
*/
-void idt_invalidate(void *addr)
+void idt_invalidate(void)
{
- struct desc_ptr idt = { .address = (unsigned long) addr, .size = 0 };
+ static const struct desc_ptr idt = { .address = 0, .size = 0 };
load_idt(&idt);
}
diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c
index 64b00b0d7fe8..1e34feebcd5d 100644
--- a/arch/x86/kernel/machine_kexec_32.c
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -232,7 +232,7 @@ void machine_kexec(struct kimage *image)
* The gdt & idt are now invalid.
* If you want to load them you must set up your own idt & gdt.
*/
- idt_invalidate(phys_to_virt(0));
+ idt_invalidate();
set_gdt(phys_to_virt(0), 0);
/* now call it */
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index b29657b76e3f..ebfb91108232 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -669,7 +669,7 @@ static void native_machine_emergency_restart(void)
break;
case BOOT_TRIPLE:
- idt_invalidate(NULL);
+ idt_invalidate();
__asm__ __volatile__("int3");
/* We're probably dead after this, but... */
--
2.31.1
On 5/14/21 6:43 PM, H. Peter Anvin wrote:
> From: "H. Peter Anvin (Intel)" <[email protected]>
>
> There is no reason to specify any specific address to
> idt_invalidate(). It looks mostly like an artifact of unifying code
> done differently by accident. The most "sensible" address to set here
> is a NULL pointer - virtual address zero, just as a visual marker.
>
> This also makes it possible to mark the struct desc_ptr in
> idt_invalidate() as static const.
>
> Signed-off-by: H. Peter Anvin (Intel) <[email protected]>
Acked-by: Andy Lutomirski <[email protected]>
> - idt_invalidate(phys_to_virt(0));
> + idt_invalidate();
This hunk is an actual change, but I'm not sure it needs to be mentioned
in the changelog.