[tip:,x86/fred] x86/fred: Make exc_page_fault() work for FRED

Message ID 170620688548.398.18235681806393352031.tip-bot2@tip-bot2
State New
Headers
Series [tip:,x86/fred] x86/fred: Make exc_page_fault() work for FRED |

Commit Message

tip-bot2 for Thomas Gleixner Jan. 25, 2024, 6:21 p.m. UTC
  The following commit has been merged into the x86/fred branch of tip:

Commit-ID:     56d86ae082ba7030b4df0b365bf102c9a63826b2
Gitweb:        https://git.kernel.org/tip/56d86ae082ba7030b4df0b365bf102c9a63826b2
Author:        H. Peter Anvin (Intel) <hpa@zytor.com>
AuthorDate:    Tue, 05 Dec 2023 02:50:10 -08:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 25 Jan 2024 19:10:32 +01:00

x86/fred: Make exc_page_fault() work for FRED

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

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-22-xin3.li@intel.com

---
 arch/x86/mm/fault.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
  

Patch

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 679b09c..fa2d699 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>
@@ -1518,8 +1519,10 @@  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);