Date: Tue, 27 Jan 2026 18:31:46 +0000 From: John Baldwin <jhb@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 093fffa296d0 - main - sys: Use __is_aligned and __align_down for some kstack alignment operations Message-ID: <69790492.f303.599c2083@gitrepo.freebsd.org>
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The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=093fffa296d009de8cebf713a58ddbf876f05c5c commit 093fffa296d009de8cebf713a58ddbf876f05c5c Author: John Baldwin <jhb@FreeBSD.org> AuthorDate: 2026-01-27 18:31:23 +0000 Commit: John Baldwin <jhb@FreeBSD.org> CommitDate: 2026-01-27 18:31:23 +0000 sys: Use __is_aligned and __align_down for some kstack alignment operations Reviewed by: kib, jhibbits Effort: CHERI upstreaming Sponsored by: AFRL, DARPA Differential Revision: https://reviews.freebsd.org/D54840 --- sys/amd64/amd64/vm_machdep.c | 3 +-- sys/i386/i386/vm_machdep.c | 3 ++- sys/powerpc/powerpc/exec_machdep.c | 4 ++-- sys/powerpc/powerpc/machdep.c | 5 ++--- sys/powerpc/powerpc/vm_machdep.c | 4 ++-- 5 files changed, 9 insertions(+), 10 deletions(-) diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c index c763ff58680e..2e180003e93d 100644 --- a/sys/amd64/amd64/vm_machdep.c +++ b/sys/amd64/amd64/vm_machdep.c @@ -93,8 +93,7 @@ set_top_of_stack_td(struct thread *td) struct savefpu * get_pcb_user_save_td(struct thread *td) { - KASSERT(((vm_offset_t)td->td_md.md_usr_fpu_save % - XSAVE_AREA_ALIGN) == 0, + KASSERT(__is_aligned(td->td_md.md_usr_fpu_save, XSAVE_AREA_ALIGN), ("Unaligned pcb_user_save area ptr %p td %p", td->td_md.md_usr_fpu_save, td)); return (td->td_md.md_usr_fpu_save); diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c index 80b45070d896..698d3b26813c 100644 --- a/sys/i386/i386/vm_machdep.c +++ b/sys/i386/i386/vm_machdep.c @@ -91,7 +91,8 @@ get_pcb_user_save_td(struct thread *td) p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE - roundup2(cpu_max_ext_state_size, XSAVE_AREA_ALIGN); - KASSERT((p % XSAVE_AREA_ALIGN) == 0, ("Unaligned pcb_user_save area")); + KASSERT(__is_aligned(p, XSAVE_AREA_ALIGN), + ("Unaligned pcb_user_save area")); return ((union savefpu *)p); } diff --git a/sys/powerpc/powerpc/exec_machdep.c b/sys/powerpc/powerpc/exec_machdep.c index 318927e01360..00c04b4ddbaa 100644 --- a/sys/powerpc/powerpc/exec_machdep.c +++ b/sys/powerpc/powerpc/exec_machdep.c @@ -1082,8 +1082,8 @@ cpu_thread_alloc(struct thread *td) { struct pcb *pcb; - pcb = (struct pcb *)((td->td_kstack + td->td_kstack_pages * PAGE_SIZE - - sizeof(struct pcb)) & ~0x3fUL); + pcb = (struct pcb *)__align_down(td->td_kstack + td->td_kstack_pages * + PAGE_SIZE - sizeof(struct pcb), 0x40); td->td_pcb = pcb; td->td_frame = (struct trapframe *)pcb - 1; } diff --git a/sys/powerpc/powerpc/machdep.c b/sys/powerpc/powerpc/machdep.c index e9979712aa9c..f4a065e1ce46 100644 --- a/sys/powerpc/powerpc/machdep.c +++ b/sys/powerpc/powerpc/machdep.c @@ -488,9 +488,8 @@ powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp, /* * Finish setting up thread0. */ - thread0.td_pcb = (struct pcb *) - ((thread0.td_kstack + thread0.td_kstack_pages * PAGE_SIZE - - sizeof(struct pcb)) & ~15UL); + thread0.td_pcb = (struct pcb *)__align_down(thread0.td_kstack + + thread0.td_kstack_pages * PAGE_SIZE - sizeof(struct pcb), 16); bzero((void *)thread0.td_pcb, sizeof(struct pcb)); pc->pc_curpcb = thread0.td_pcb; diff --git a/sys/powerpc/powerpc/vm_machdep.c b/sys/powerpc/powerpc/vm_machdep.c index 1fd853783cc8..00fdc301a7e7 100644 --- a/sys/powerpc/powerpc/vm_machdep.c +++ b/sys/powerpc/powerpc/vm_machdep.c @@ -123,8 +123,8 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) if (td1 == curthread) cpu_update_pcb(td1); - pcb = (struct pcb *)((td2->td_kstack + - td2->td_kstack_pages * PAGE_SIZE - sizeof(struct pcb)) & ~0x3fUL); + pcb = (struct pcb *)__align_down(td2->td_kstack + + td2->td_kstack_pages * PAGE_SIZE - sizeof(struct pcb), 0x40); td2->td_pcb = pcb; /* Copy the pcb */home | help
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