git: 97ce8f7d2b8e - main - amd64: define and use STACKALIGN and REDZONE_SZ

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=97ce8f7d2b8eff42460f60e8c49d9849b58b6e81

commit 97ce8f7d2b8eff42460f60e8c49d9849b58b6e81
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2026-02-07 00:36:44 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2026-02-09 17:57:00 +0000

    amd64: define and use STACKALIGN and REDZONE_SZ
    
    Reviewed by:    brooks, emaste, jhb
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D55151
---
 sys/amd64/amd64/exec_machdep.c | 4 ++--
 sys/amd64/amd64/machdep.c      | 6 +++---
 sys/amd64/amd64/mp_machdep.c   | 4 ++--
 sys/amd64/include/param.h      | 3 +++
 4 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/sys/amd64/amd64/exec_machdep.c b/sys/amd64/amd64/exec_machdep.c
index 6752b716deb5..b5eda6f83d46 100644
--- a/sys/amd64/amd64/exec_machdep.c
+++ b/sys/amd64/amd64/exec_machdep.c
@@ -151,7 +151,7 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
 		td->td_sigstk.ss_flags |= SS_ONSTACK;
 #endif
 	} else
-		sp = (char *)regs->tf_rsp - 128;
+		sp = (char *)regs->tf_rsp - REDZONE_SZ;
 	if (xfpusave != NULL) {
 		sp -= xfpusave_len;
 		sp = (char *)((unsigned long)sp & ~0x3Ful);
@@ -159,7 +159,7 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
 	}
 	sp -= sizeof(struct sigframe);
 	/* Align to 16 bytes. */
-	sfp = (struct sigframe *)((unsigned long)sp & ~0xFul);
+	sfp = (struct sigframe *)STACKALIGN(sp);
 
 	/* Build the argument list for the signal handler. */
 	regs->tf_rdi = sig;			/* arg 1 in %rdi */
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index ae5df475f046..b0da0b763b22 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -1216,8 +1216,8 @@ amd64_bsp_pcpu_init2(uint64_t rsp0)
 {
 
 	PCPU_SET(rsp0, rsp0);
-	PCPU_SET(pti_rsp0, ((vm_offset_t)PCPU_PTR(pti_stack) +
-	    PC_PTI_STACK_SZ * sizeof(uint64_t)) & ~0xful);
+	PCPU_SET(pti_rsp0, STACKALIGN((vm_offset_t)PCPU_PTR(pti_stack) +
+	    PC_PTI_STACK_SZ * sizeof(uint64_t)));
 	PCPU_SET(curpcb, thread0.td_pcb);
 }
 
@@ -1585,7 +1585,7 @@ hammer_time(u_int64_t modulep, u_int64_t physfree)
 	/* make an initial tss so cpu can get interrupt stack on syscall! */
 	rsp0 = thread0.td_md.md_stack_base;
 	/* Ensure the stack is aligned to 16 bytes */
-	rsp0 &= ~0xFul;
+	rsp0 = STACKALIGN(rsp0);
 	PCPU_PTR(common_tss)->tss_rsp0 = rsp0;
 	amd64_bsp_pcpu_init2(rsp0);
 
diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c
index 61f1bdb6f942..05e4109e73bb 100644
--- a/sys/amd64/amd64/mp_machdep.c
+++ b/sys/amd64/amd64/mp_machdep.c
@@ -217,8 +217,8 @@ init_secondary(void)
 	pc->pc_curthread = 0;
 	pc->pc_tssp = &pc->pc_common_tss;
 	pc->pc_rsp0 = 0;
-	pc->pc_pti_rsp0 = (((vm_offset_t)&pc->pc_pti_stack +
-	    PC_PTI_STACK_SZ * sizeof(uint64_t)) & ~0xful);
+	pc->pc_pti_rsp0 = STACKALIGN(((vm_offset_t)&pc->pc_pti_stack +
+	    PC_PTI_STACK_SZ * sizeof(uint64_t)));
 	gdt = pc->pc_gdt;
 	pc->pc_tss = (struct system_segment_descriptor *)&gdt[GPROC0_SEL];
 	pc->pc_fs32p = &gdt[GUFS32_SEL];
diff --git a/sys/amd64/include/param.h b/sys/amd64/include/param.h
index 642a031d8841..079937d9f53a 100644
--- a/sys/amd64/include/param.h
+++ b/sys/amd64/include/param.h
@@ -43,6 +43,9 @@
 
 #include <sys/_align.h>
 
+#define	STACKALIGNBYTES	(16 - 1)
+#define	REDZONE_SZ	128
+
 /*
  * Machine dependent constants for AMD64.
  */