Date: Tue, 28 Jul 2026 10:19:45 +0000 From: Olivier Houchard <cognet@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: c6f5d8fb269f - main - arm64: Use the fault handler when one is provided Message-ID: <6a688241.20d93.6a28e6e@gitrepo.freebsd.org>
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The branch main has been updated by cognet: URL: https://cgit.FreeBSD.org/src/commit/?id=c6f5d8fb269fd67a8206420b4e7d67a93bc80733 commit c6f5d8fb269fd67a8206420b4e7d67a93bc80733 Author: Olivier Houchard <cognet@FreeBSD.org> AuthorDate: 2026-07-23 23:47:21 +0000 Commit: Olivier Houchard <cognet@FreeBSD.org> CommitDate: 2026-07-28 10:08:56 +0000 arm64: Use the fault handler when one is provided In align_abort() and tag_check_abort(), if we got a fault while in kernel, do not panic if a fault handler has been provided. We may get such a fault when trying to read or write userland data, it can at least happen with _umtx_op() if an unaligned pointer is provided. Instead, just let the fault handler deal with it. MFC After: 1 week Approved by: andrew Differential Revision: https://reviews.freebsd.org/D58426 --- sys/arm64/arm64/trap.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/sys/arm64/arm64/trap.c b/sys/arm64/arm64/trap.c index 3afeb34abd5f..e688b9cb76a3 100644 --- a/sys/arm64/arm64/trap.c +++ b/sys/arm64/arm64/trap.c @@ -217,6 +217,17 @@ align_abort(struct thread *td, struct trapframe *frame, uint64_t esr, uint64_t far, int lower) { if (!lower) { + /* + * Accessing unaligned memory may fault when using atomics. + * Make sure we don't panic if we're doing an unaligned + * access to userland memory, as can happen with _umtx_op() + */ + if (td->td_intr_nesting_level == 0 && + td->td_pcb->pcb_onfault != 0) { + frame->tf_elr = td->td_pcb->pcb_onfault; + return; + } + print_registers(frame); print_gp_register("far", far); printf(" esr: 0x%.16lx\n", esr); @@ -262,6 +273,14 @@ tag_check_abort(struct thread *td, struct trapframe *frame, uint64_t esr, * at EL0 and a kernel panic if at EL1. */ if (!lower) { + /* + * If we have a fault handler, let it decide what to do. + */ + if (td->td_intr_nesting_level == 0 && + td->td_pcb->pcb_onfault != 0) { + frame->tf_elr = td->td_pcb->pcb_onfault; + return; + } print_registers(frame); print_gp_register("far", far); printf(" esr: 0x%.16lx\n", esr);home | help
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