[tip: x86/cleanups] x86/boot/64: Strip percpu address space when setting up GDT descriptors
From: tip-bot2 for Uros Bizjak
Date: Sun Aug 25 2024 - 10:12:22 EST
The following commit has been merged into the x86/cleanups branch of tip:
Commit-ID: b51207dc02ec3aeaa849e419f79055d7334845b6
Gitweb: https://git.kernel.org/tip/b51207dc02ec3aeaa849e419f79055d7334845b6
Author: Uros Bizjak <ubizjak@xxxxxxxxx>
AuthorDate: Mon, 19 Aug 2024 10:33:13 +02:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Sun, 25 Aug 2024 16:07:51 +02:00
x86/boot/64: Strip percpu address space when setting up GDT descriptors
init_per_cpu_var() returns a pointer in the percpu address space while
rip_rel_ptr() expects a pointer in the generic address space.
When strict address space checks are enabled, GCC's named address space
checks fail:
asm.h:124:63: error: passing argument 1 of 'rip_rel_ptr' from
pointer to non-enclosed address space
Add a explicit cast to remove address space of the returned pointer.
Fixes: 11e36b0f7c21 ("x86/boot/64: Load the final kernel GDT during early boot directly, remove startup_gdt[]")
Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20240819083334.148536-1-ubizjak@xxxxxxxxx
---
arch/x86/kernel/head64.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index a817ed0..4b9d455 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -559,10 +559,11 @@ void early_setup_idt(void)
*/
void __head startup_64_setup_gdt_idt(void)
{
+ struct desc_struct *gdt = (void *)(__force unsigned long)init_per_cpu_var(gdt_page.gdt);
void *handler = NULL;
struct desc_ptr startup_gdt_descr = {
- .address = (unsigned long)&RIP_REL_REF(init_per_cpu_var(gdt_page.gdt)),
+ .address = (unsigned long)&RIP_REL_REF(*gdt),
.size = GDT_SIZE - 1,
};