From: Joerg Roedel <jroedel@xxxxxxx>
Introduce a helper to check whether an exception came from the syscall
gap and use it in the SEV-ES code
Fixes: 315562c9af3d5 ("x86/sev-es: Adjust #VC IST Stack on entering NMI handler")
Cc: stable@xxxxxxxxxxxxxxx # 5.10+
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
arch/x86/include/asm/ptrace.h | 8 ++++++++
arch/x86/kernel/traps.c | 3 +--
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index d8324a236696..14854b2c4944 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -94,6 +94,8 @@ struct pt_regs {
#include <asm/paravirt_types.h>
#endif
+#include <asm/proto.h>
+
struct cpuinfo_x86;
struct task_struct;
@@ -175,6 +177,12 @@ static inline bool any_64bit_mode(struct pt_regs *regs)
#ifdef CONFIG_X86_64
#define current_user_stack_pointer() current_pt_regs()->sp
#define compat_user_stack_pointer() current_pt_regs()->sp
+
+static inline bool from_syscall_gap(struct pt_regs *regs)
+{
+ return (regs->ip >= (unsigned long)entry_SYSCALL_64 &&
+ regs->ip < (unsigned long)entry_SYSCALL_64_safe_stack);
+}
#endif
static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 7f5aec758f0e..b4f2b4e9066d 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -694,8 +694,7 @@ asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *r
* In the SYSCALL entry path the RSP value comes from user-space - don't
* trust it and switch to the current kernel stack
*/
- if (regs->ip >= (unsigned long)entry_SYSCALL_64 &&
- regs->ip < (unsigned long)entry_SYSCALL_64_safe_stack) {
+ if (from_syscall_gap(regs)) {
sp = this_cpu_read(cpu_current_top_of_stack);
goto sync;
}
--
2.30.0
