git: fa10e2fb8822 - stable/14 - amd64: add mc_tlsbase member to mcontext

From: Konstantin Belousov <kib_at_FreeBSD.org>
Date: Thu, 12 Jun 2025 18:03:00 UTC
The branch stable/14 has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=fa10e2fb88224b1b30abb6c94a9cf4c99ce5103f

commit fa10e2fb88224b1b30abb6c94a9cf4c99ce5103f
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2025-05-22 06:55:50 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2025-06-12 18:02:50 +0000

    amd64: add mc_tlsbase member to mcontext
    
    (cherry picked from commit eea3e4dd9703a252509d75814049aa8da5007ebb)
---
 sys/amd64/amd64/exec_machdep.c | 6 ++++++
 sys/x86/include/frame.h        | 1 +
 sys/x86/include/ucontext.h     | 8 ++++++--
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/sys/amd64/amd64/exec_machdep.c b/sys/amd64/amd64/exec_machdep.c
index 71e33e5b14c1..b9c69b7d5a2f 100644
--- a/sys/amd64/amd64/exec_machdep.c
+++ b/sys/amd64/amd64/exec_machdep.c
@@ -637,6 +637,8 @@ get_mcontext(struct thread *td, mcontext_t *mcp, int flags)
 	mcp->mc_gsbase = pcb->pcb_gsbase;
 	mcp->mc_xfpustate = 0;
 	mcp->mc_xfpustate_len = 0;
+	mcp->mc_tlsbase = (pcb->pcb_flags & PCB_TLSBASE) != 0 ?
+	    pcb->pcb_tlsbase : 0;
 	bzero(mcp->mc_spare, sizeof(mcp->mc_spare));
 	return (0);
 }
@@ -711,6 +713,10 @@ set_mcontext(struct thread *td, mcontext_t *mcp)
 		pcb->pcb_fsbase = mcp->mc_fsbase;
 		pcb->pcb_gsbase = mcp->mc_gsbase;
 	}
+	if ((mcp->mc_flags & _MC_HASTLSBASE) != 0) {
+		pcb->pcb_tlsbase = mcp->mc_tlsbase;
+		set_pcb_flags(pcb, PCB_TLSBASE);
+	}
 	return (0);
 }
 
diff --git a/sys/x86/include/frame.h b/sys/x86/include/frame.h
index 80e4a968ed60..a8836a705d39 100644
--- a/sys/x86/include/frame.h
+++ b/sys/x86/include/frame.h
@@ -154,6 +154,7 @@ struct trapframe {
 #define	TF_HASSEGS	0x1
 #define	TF_HASBASES	0x2
 #define	TF_HASFPXSTATE	0x4
+#define	TF_RESERV0	0x8 /* no tlsbase in the trapframe */
 #endif /* __amd64__ */
 
 #endif /* _MACHINE_FRAME_H_ */
diff --git a/sys/x86/include/ucontext.h b/sys/x86/include/ucontext.h
index b7964e8c7141..00edc8c16bce 100644
--- a/sys/x86/include/ucontext.h
+++ b/sys/x86/include/ucontext.h
@@ -99,7 +99,9 @@ typedef struct __mcontext {
 #define	_MC_HASSEGS	0x1
 #define	_MC_HASBASES	0x2
 #define	_MC_HASFPXSTATE	0x4
-#define	_MC_FLAG_MASK	(_MC_HASSEGS | _MC_HASBASES | _MC_HASFPXSTATE)
+#define	_MC_HASTLSBASE	0x8
+#define	_MC_FLAG_MASK	(_MC_HASSEGS | _MC_HASBASES | _MC_HASFPXSTATE | \
+    _MC_HASTLSBASE)
 
 typedef struct __mcontext {
 	/*
@@ -158,7 +160,9 @@ typedef struct __mcontext {
 	__register_t	mc_xfpustate;
 	__register_t	mc_xfpustate_len;
 
-	long	mc_spare[4];
+	__register_t	mc_tlsbase;
+
+	long	mc_spare[3];
 } mcontext_t;
 #endif /* __amd64__ */