diff mbox series

[v12,23/37] x86/fred: Make exc_page_fault() work for FRED

Message ID 20231003062458.23552-24-xin3.li@intel.com (mailing list archive)
State Superseded
Headers show
Series x86: enable FRED for x86-64 | expand

Commit Message

Li, Xin3 Oct. 3, 2023, 6:24 a.m. UTC 
From: "H. Peter Anvin (Intel)" <hpa@zytor.com>

On a FRED system, the faulting address (CR2) is passed on the stack,
to avoid the problem of transient state. Thus we get the page fault
address from the stack instead of CR2.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Xin Li <xin3.li@intel.com>
---
 arch/x86/mm/fault.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Borislav Petkov Nov. 28, 2023, 10:02 a.m. UTC | #1 
On Mon, Oct 02, 2023 at 11:24:44PM -0700, Xin Li wrote:
> From: "H. Peter Anvin (Intel)" <hpa@zytor.com>
> 
> On a FRED system, the faulting address (CR2) is passed on the stack,
> to avoid the problem of transient state. Thus we get the page fault
						^^

Please use passive voice in your commit message: no "we" or "I", etc,
and describe your changes in imperative mood.
diff mbox series

Patch

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index ab778eac1952..7675bc067153 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -34,6 +34,7 @@ 
 #include <asm/kvm_para.h>		/* kvm_handle_async_pf		*/
 #include <asm/vdso.h>			/* fixup_vdso_exception()	*/
 #include <asm/irq_stack.h>
+#include <asm/fred.h>
 
 #define CREATE_TRACE_POINTS
 #include <asm/trace/exceptions.h>
@@ -1516,8 +1517,10 @@  handle_page_fault(struct pt_regs *regs, unsigned long error_code,
 
 DEFINE_IDTENTRY_RAW_ERRORCODE(exc_page_fault)
 {
-	unsigned long address = read_cr2();
 	irqentry_state_t state;
+	unsigned long address;
+
+	address = cpu_feature_enabled(X86_FEATURE_FRED) ? fred_event_data(regs) : read_cr2();
 
 	prefetchw(&current->mm->mmap_lock);