From mboxrd@z Thu Jan 1 00:00:00 1970 From: Conor Dooley Date: Wed, 1 Mar 2023 17:56:56 +0000 Subject: [PATCH -next v14 12/19] riscv: signal: check fp-reserved words unconditionally In-Reply-To: <20230224170118.16766-13-andy.chiu@sifive.com> References: <20230224170118.16766-1-andy.chiu@sifive.com> <20230224170118.16766-13-andy.chiu@sifive.com> Message-ID: List-Id: To: kvm-riscv@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Fri, Feb 24, 2023 at 05:01:11PM +0000, Andy Chiu wrote: > In order to let kernel/user locate and identify an extension context on > the existing sigframe, we are going to utilize reserved space of fp and > encode the information there. And since the sigcontext has already > preserved a space for fp context w or w/o CONFIG_FPU, we move those > reserved words checking/setting routine back into generic code. > > This commit also undone an additional logical change carried by the > refactor commit 007f5c3589578 > ("Refactor FPU code in signal setup/return procedures"). Originally we > did not restore fp context if restoring of gpr have failed. And it was > fine on the other side. In such way the kernel could keep the regfiles > intact, and potentially react at the failing point of restore. > > Signed-off-by: Andy Chiu > --- > @@ -90,11 +66,29 @@ static long restore_sigcontext(struct pt_regs *regs, > struct sigcontext __user *sc) > { > long err; > + size_t i; > + > /* sc_regs is structured the same as the start of pt_regs */ > err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs)); > + if (unlikely(err)) > + return err; > /* Restore the floating-point state. */ Please preserve the newline after return from where you moved this from. > - if (has_fpu()) > - err |= restore_fp_state(regs, &sc->sc_fpregs); > + if (has_fpu()) { > + err = restore_fp_state(regs, &sc->sc_fpregs); > + if (unlikely(err)) > + return err; > + } > @@ -145,11 +139,16 @@ static long setup_sigcontext(struct rt_sigframe __user *frame, > { > struct sigcontext __user *sc = &frame->uc.uc_mcontext; > long err; > + size_t i; > + > /* sc_regs is structured the same as the start of pt_regs */ > err = __copy_to_user(&sc->sc_regs, regs, sizeof(sc->sc_regs)); > /* Save the floating-point state. */ > if (has_fpu()) > err |= save_fp_state(regs, &sc->sc_fpregs); > + /* We support no other extension state at this time. */ > + for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++) > + err |= __put_user(0, &sc->sc_fpregs.q.reserved[i]); > return err; And one before the return here would not go amiss. Those are nitpick bits though, so: Acked-by: Conor Dooley Cheers, Conor. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 228 bytes Desc: not available URL: