[PATCH v1 08/26] x86/traps: Define RMP violation #PF error code

Michael Roth
2023-12-30T16:21:30Z

From: Brijesh Singh <brijesh.singh@amd.com>

Bit 31 in the page fault-error bit will be set when processor encounters
an RMP violation.

While at it, use the BIT() macro.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off by: Ashish Kalra <ashish.kalra@amd.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
arch/x86/include/asm/trap_pf.h | 20 ++++++++++++--------
arch/x86/mm/fault.c | 1 +
2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/trap_pf.h b/arch/x86/include/asm/trap_pf.h
index afa524325e55..7fc4db774dd6 100644
--- a/arch/x86/include/asm/trap_pf.h
+++ b/arch/x86/include/asm/trap_pf.h
@@ -2,6 +2,8 @@
#ifndef _ASM_X86_TRAP_PF_H
#define _ASM_X86_TRAP_PF_H

+#include <linux/bits.h> /* BIT() macro */
+
/*
* Page fault error code bits:
*
@@ -13,16 +15,18 @@
* bit 5 == 1: protection keys block access
* bit 6 == 1: shadow stack access fault
* bit 15 == 1: SGX MMU page-fault
+ * bit 31 == 1: fault was due to RMP violation
*/
enum x86_pf_error_code {
- X86_PF_PROT = 1 << 0,
- X86_PF_WRITE = 1 << 1,
- X86_PF_USER = 1 << 2,
- X86_PF_RSVD = 1 << 3,
- X86_PF_INSTR = 1 << 4,
- X86_PF_PK = 1 << 5,
- X86_PF_SHSTK = 1 << 6,
- X86_PF_SGX = 1 << 15,
+ X86_PF_PROT = BIT(0),
+ X86_PF_WRITE = BIT(1),
+ X86_PF_USER = BIT(2),
+ X86_PF_RSVD = BIT(3),
+ X86_PF_INSTR = BIT(4),
+ X86_PF_PK = BIT(5),
+ X86_PF_SHSTK = BIT(6),
+ X86_PF_SGX = BIT(15),
+ X86_PF_RMP = BIT(31),
};

#endif /* _ASM_X86_TRAP_PF_H */
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index ab778eac1952..7858b9515d4a 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -547,6 +547,7 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long ad
!(error_code & X86_PF_PROT) ? "not-present page" :
(error_code & X86_PF_RSVD) ? "reserved bit violation" :
(error_code & X86_PF_PK) ? "protection keys violation" :
+ (error_code & X86_PF_RMP) ? "RMP violation" :
"permissions violation");

if (!(error_code & X86_PF_USER) && user_mode(regs)) {
--
2.25.1