Date: Fri, 27 Oct 2023 09:43:13 GMT From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 070a4ff82a34 - main - arm64: Use the Linux sigframe to restore registers Message-ID: <202310270943.39R9hDsc008922@gitrepo.freebsd.org>
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The branch main has been updated by andrew: URL: https://cgit.FreeBSD.org/src/commit/?id=070a4ff82a34652d533f9315ae9ad0aa8f1fdeb2 commit 070a4ff82a34652d533f9315ae9ad0aa8f1fdeb2 Author: Andrew Turner <andrew@FreeBSD.org> AuthorDate: 2023-10-25 09:50:11 +0000 Commit: Andrew Turner <andrew@FreeBSD.org> CommitDate: 2023-10-27 09:32:24 +0000 arm64: Use the Linux sigframe to restore registers When returning from a Linux signal use the Linux sigframe to find the register values to restore. Remove the FreeBSD ucontext from the stack as it's now unneeded. Reviewed by: dchagin, emaste Sponsored by: Arm Ltd Differential Revision: https://reviews.freebsd.org/D42360 --- sys/arm64/linux/linux_sigframe.h | 1 - sys/arm64/linux/linux_sysvec.c | 96 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 88 insertions(+), 9 deletions(-) diff --git a/sys/arm64/linux/linux_sigframe.h b/sys/arm64/linux/linux_sigframe.h index e903fea295dc..2a004f4db74d 100644 --- a/sys/arm64/linux/linux_sigframe.h +++ b/sys/arm64/linux/linux_sigframe.h @@ -76,7 +76,6 @@ struct l_sigframe { /* frame_record */ uint64_t fp; uint64_t lr; - ucontext_t uc; }; #define LINUX_MINSIGSTKSZ roundup(sizeof(struct l_sigframe), 16) diff --git a/sys/arm64/linux/linux_sysvec.c b/sys/arm64/linux/linux_sysvec.c index a850d5e34bc0..4b5544841313 100644 --- a/sys/arm64/linux/linux_sysvec.c +++ b/sys/arm64/linux/linux_sysvec.c @@ -187,28 +187,109 @@ linux_exec_setregs(struct thread *td, struct image_params *imgp, bzero(&pcb->pcb_dbg_regs, sizeof(pcb->pcb_dbg_regs)); } +static bool +linux_parse_sigreturn_ctx(struct thread *td, struct l_sigcontext *sc) +{ + struct l_fpsimd_context *fpsimd; + struct _l_aarch64_ctx *ctx; + int offset; + + offset = 0; + while (1) { + /* The offset must be 16 byte aligned */ + if ((offset & 15) != 0) + return (false); + + /* Check for buffer overflow of the ctx */ + if ((offset + sizeof(*ctx)) > + sizeof(sc->__reserved)) + return (false); + + ctx = (struct _l_aarch64_ctx *)&sc->__reserved[offset]; + + /* Check for buffer overflow of the data */ + if ((offset + ctx->size) > sizeof(sc->__reserved)) + return (false); + + switch(ctx->magic) { + case 0: + if (ctx->size != 0) + return (false); + return (true); + case L_ESR_MAGIC: + /* Ignore */ + break; +#ifdef VFP + case L_FPSIMD_MAGIC: + fpsimd = (struct l_fpsimd_context *)ctx; + + /* + * Discard any vfp state for the current thread, we + * are about to override it. + */ + critical_enter(); + vfp_discard(td); + critical_exit(); + + td->td_pcb->pcb_fpustate.vfp_fpcr = fpsimd->fpcr; + td->td_pcb->pcb_fpustate.vfp_fpsr = fpsimd->fpsr; + memcpy(td->td_pcb->pcb_fpustate.vfp_regs, + fpsimd->vregs, sizeof(fpsimd->vregs)); + + break; +#endif + default: + return (false); + } + + offset += ctx->size; + } + +} + int linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) { + struct l_rt_sigframe *sf; struct l_sigframe *frame; - ucontext_t uc; struct trapframe *tf; + sigset_t bmask; int error; + sf = malloc(sizeof(*sf), M_LINUX, M_WAITOK | M_ZERO); + tf = td->td_frame; frame = (struct l_sigframe *)tf->tf_sp; + error = copyin((void *)&frame->sf, sf, sizeof(*sf)); + if (error != 0) { + free(sf, M_LINUX); + return (error); + } - if (copyin((void *)&frame->uc, &uc, sizeof(uc))) - return (EFAULT); + memcpy(tf->tf_x, sf->sf_uc.uc_sc.regs, sizeof(tf->tf_x)); + tf->tf_lr = sf->sf_uc.uc_sc.regs[30]; + tf->tf_sp = sf->sf_uc.uc_sc.sp; + tf->tf_elr = sf->sf_uc.uc_sc.pc; - error = set_mcontext(td, &uc.uc_mcontext); - if (error != 0) - return (error); + if ((sf->sf_uc.uc_sc.pstate & PSR_M_MASK) != PSR_M_EL0t || + (sf->sf_uc.uc_sc.pstate & PSR_AARCH32) != 0 || + (sf->sf_uc.uc_sc.pstate & PSR_DAIF) != + (td->td_frame->tf_spsr & PSR_DAIF)) + goto einval; + tf->tf_spsr = sf->sf_uc.uc_sc.pstate; + + if (!linux_parse_sigreturn_ctx(td, &sf->sf_uc.uc_sc)) + goto einval; /* Restore signal mask. */ - kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0); + linux_to_bsd_sigset(&sf->sf_uc.uc_sigmask, &bmask); + kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); + free(sf, M_LINUX); return (EJUSTRETURN); +einval: + free(sf, M_LINUX); + return (EINVAL); } static void @@ -310,7 +391,6 @@ linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) } memcpy(&frame->sf.sf_uc.uc_stack, &uc_stack, sizeof(uc_stack)); - memcpy(&frame->uc, &uc, sizeof(uc)); /* Copy the sigframe out to the user's stack. */ if (copyout(frame, fp, sizeof(*fp)) != 0) {
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