From 71518294bb57d3d9c8252704b21a549d58bd8f46 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Wed, 15 Oct 2025 22:07:13 -0400
Subject: kern/amd64: trap: Copy trapframe on syscall entry

Ensure that the trapframe in the PCB is the latest, upon kernel entry we
copy it so it isn't stale.

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 src/sys/arch/amd64/cpu/trap.c | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'src')

diff --git a/src/sys/arch/amd64/cpu/trap.c b/src/sys/arch/amd64/cpu/trap.c
index 921a036..ae3a0cc 100644
--- a/src/sys/arch/amd64/cpu/trap.c
+++ b/src/sys/arch/amd64/cpu/trap.c
@@ -39,6 +39,7 @@
 #include <sys/syslog.h>
 #include <sys/syscall.h>
 #include <machine/trap.h>
+#include <string.h>
 
 /*
  * Trap type to type string conversion table
@@ -154,6 +155,7 @@ trap_syscall(struct trapframe *tf)
     struct syscall_domain *scdp;
     struct syscall_win *scwp;
     struct proc *self;
+    struct md_pcb *pcbp;
     struct syscall_args scargs = {
         .arg[0] = tf->rdi,
         .arg[1] = tf->rsi,
@@ -179,6 +181,9 @@ trap_syscall(struct trapframe *tf)
         return;
     }
 
+    pcbp = &self->pcb;
+    memcpy(&pcbp->tf, tf, sizeof(pcbp->tf));
+
     if (tf->rax < scwp->nimpl && tf->rax > 0) {
         tf->rax = scwp->sctab[tf->rax](&scargs);
     }
-- 
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