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>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-22-xin3.li@intel.com

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 679b09cfe241c72e7f85bd7bbd406d59a259bf2a..fa2d69951f25c1f188afbef3be5b01b8b5a6e856 100644 (file)
--- 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);