Date: Tue, 27 Jan 2026 18:31:45 +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: 9272b7806266 - main - powerpc: Fix alignment of initial PCB on kstack Message-ID: <69790491.f894.6eac006@gitrepo.freebsd.org>
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The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=9272b780626640ce9b9ac378fbdd2783aaa33625 commit 9272b780626640ce9b9ac378fbdd2783aaa33625 Author: John Baldwin <jhb@FreeBSD.org> AuthorDate: 2026-01-27 18:30:46 +0000 Commit: John Baldwin <jhb@FreeBSD.org> CommitDate: 2026-01-27 18:30:46 +0000 powerpc: Fix alignment of initial PCB on kstack Commit cc81c44dd806737f98b4fd4094674dd71c8749f3 aimed to consolidate duplicated code between the Book-E and AIM backends. For cpu_thread_alloc cpu_thread_alloc and cpu_fork it used the AIM functions which used a bogus alignment mask (~0x2f). The Book-E functions used a proper alignment mask (~0x3f). The AIM functions appear to have been busted since they were first imported in commit 919cb3362fded33aca682a6ac57777f8fff86e36. To fix, use the Book-E mask which requests 64 byte alignment. Probably this was harmless in practice since td_kstack is page aligned and struct pcb is probably a multiple of 32 bytes in size, so the 0x10 bit should have been clear anyway. Reviewed by: fuz, jhibbits Fixes: cc81c44dd806 ("Unify ABI-related bits of the Book-E and AIM...") Effort: CHERI upstreaming Sponsored by: AFRL, DARPA Differential Revision: https://reviews.freebsd.org/D54839 --- sys/powerpc/powerpc/exec_machdep.c | 2 +- sys/powerpc/powerpc/vm_machdep.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/sys/powerpc/powerpc/exec_machdep.c b/sys/powerpc/powerpc/exec_machdep.c index 18c9bddb84c5..318927e01360 100644 --- a/sys/powerpc/powerpc/exec_machdep.c +++ b/sys/powerpc/powerpc/exec_machdep.c @@ -1083,7 +1083,7 @@ cpu_thread_alloc(struct thread *td) struct pcb *pcb; pcb = (struct pcb *)((td->td_kstack + td->td_kstack_pages * PAGE_SIZE - - sizeof(struct pcb)) & ~0x2fUL); + sizeof(struct pcb)) & ~0x3fUL); td->td_pcb = pcb; td->td_frame = (struct trapframe *)pcb - 1; } diff --git a/sys/powerpc/powerpc/vm_machdep.c b/sys/powerpc/powerpc/vm_machdep.c index d47beedb595e..1fd853783cc8 100644 --- a/sys/powerpc/powerpc/vm_machdep.c +++ b/sys/powerpc/powerpc/vm_machdep.c @@ -124,7 +124,7 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) cpu_update_pcb(td1); pcb = (struct pcb *)((td2->td_kstack + - td2->td_kstack_pages * PAGE_SIZE - sizeof(struct pcb)) & ~0x2fUL); + td2->td_kstack_pages * PAGE_SIZE - sizeof(struct pcb)) & ~0x3fUL); td2->td_pcb = pcb; /* Copy the pcb */home | help
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