Date: Thu, 23 Feb 2023 16:50:57 GMT From: =?utf-8?Q?Kornel=20Dul=C4=99ba?= <kd@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 4d2427f2c445 - main - arm: Unbreak debugging programs that use FP instructions Message-ID: <202302231650.31NGovLI086448@gitrepo.freebsd.org>
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The branch main has been updated by kd: URL: https://cgit.FreeBSD.org/src/commit/?id=4d2427f2c4451babe1bad600ae02c8a7c66031fe commit 4d2427f2c4451babe1bad600ae02c8a7c66031fe Author: Kornel Dulęba <kd@FreeBSD.org> AuthorDate: 2023-02-20 14:44:36 +0000 Commit: Kornel Dulęba <kd@FreeBSD.org> CommitDate: 2023-02-23 16:50:26 +0000 arm: Unbreak debugging programs that use FP instructions Contrary to arm64, on armv7 get_vfpcontext/set_vfpcontext can be called from cpu_ptrace. This can be triggered when gdb hits a breakpoint in a userspace program. Relax td == currthread assertion to account for that situation. While here update an outdated comment in vfp_discard. Reported by: Mark Millard <marklmi@yahoo.com> Tested by: Mark Millard <marklmi@yahoo.com> Differential Revision: https://reviews.freebsd.org/D38696 --- sys/arm/arm/exec_machdep.c | 17 ++++++----------- sys/arm/arm/vfp.c | 2 -- 2 files changed, 6 insertions(+), 13 deletions(-) diff --git a/sys/arm/arm/exec_machdep.c b/sys/arm/arm/exec_machdep.c index c14bd51146ef..96b382c9083f 100644 --- a/sys/arm/arm/exec_machdep.c +++ b/sys/arm/arm/exec_machdep.c @@ -100,19 +100,18 @@ get_vfpcontext(struct thread *td, mcontext_vfp_t *vfp) { struct pcb *pcb; - MPASS(td == curthread); + MPASS(td == curthread || TD_IS_SUSPENDED(td) || + P_SHOULDSTOP(td->td_proc)); pcb = td->td_pcb; - if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) { + if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0 && td == curthread) { critical_enter(); vfp_store(&pcb->pcb_vfpstate, false); critical_exit(); } KASSERT(pcb->pcb_vfpsaved == &pcb->pcb_vfpstate, ("Called get_vfpcontext while the kernel is using the VFP")); - memcpy(vfp->mcv_reg, pcb->pcb_vfpstate.reg, - sizeof(vfp->mcv_reg)); - vfp->mcv_fpscr = pcb->pcb_vfpstate.fpscr; + memcpy(vfp, &pcb->pcb_vfpstate, sizeof(*vfp)); } /* @@ -123,19 +122,15 @@ set_vfpcontext(struct thread *td, mcontext_vfp_t *vfp) { struct pcb *pcb; - MPASS(td == curthread); - pcb = td->td_pcb; - if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) { + if (td == curthread) { critical_enter(); vfp_discard(td); critical_exit(); } KASSERT(pcb->pcb_vfpsaved == &pcb->pcb_vfpstate, ("Called set_vfpcontext while the kernel is using the VFP")); - memcpy(pcb->pcb_vfpstate.reg, vfp->mcv_reg, - sizeof(pcb->pcb_vfpstate.reg)); - pcb->pcb_vfpstate.fpscr = vfp->mcv_fpscr; + memcpy(&pcb->pcb_vfpstate, vfp, sizeof(*vfp)); } #endif diff --git a/sys/arm/arm/vfp.c b/sys/arm/arm/vfp.c index 915d65c1b790..d51c4b6e0618 100644 --- a/sys/arm/arm/vfp.c +++ b/sys/arm/arm/vfp.c @@ -334,8 +334,6 @@ vfp_store(struct vfp_state *vfpsave, boolean_t disable_vfp) * The current thread is dying. If the state currently in the hardware belongs * to the current thread, set fpcurthread to NULL to indicate that the VFP * hardware state does not belong to any thread. If the VFP is on, turn it off. - * Called only from cpu_throw(), so we don't have to worry about a context - * switch here. */ void vfp_discard(struct thread *td)
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