From: Conor Dooley <conor@kernel.org>
To: Andy Chiu <andy.chiu@sifive.com>
Cc: linux-riscv@lists.infradead.org, palmer@dabbelt.com,
anup@brainfault.org, atishp@atishpatra.org,
kvm-riscv@lists.infradead.org, kvm@vger.kernel.org,
vineetg@rivosinc.com, greentime.hu@sifive.com,
guoren@linux.alibaba.com,
Paul Walmsley <paul.walmsley@sifive.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Vincent Chen <vincent.chen@sifive.com>,
Guo Ren <guoren@kernel.org>,
Conor Dooley <conor.dooley@microchip.com>,
Andrew Bresticker <abrestic@rivosinc.com>
Subject: Re: [PATCH -next v14 12/19] riscv: signal: check fp-reserved words unconditionally
Date: Wed, 1 Mar 2023 17:56:56 +0000 [thread overview]
Message-ID: <Y/+R6NfBHSGGI3MX@spud> (raw)
In-Reply-To: <20230224170118.16766-13-andy.chiu@sifive.com>
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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 <andy.chiu@sifive.com>
> ---
> @@ -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 <conor.dooley@microchip.com>
Cheers,
Conor.
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next prev parent reply other threads:[~2023-03-01 17:57 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-24 17:00 [PATCH -next v14 00/19] riscv: Add vector ISA support Andy Chiu
2023-02-24 17:01 ` [PATCH -next v14 01/19] riscv: Rename __switch_to_aux -> fpu Andy Chiu
2023-02-28 21:56 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 02/19] riscv: Extending cpufeature.c to detect V-extension Andy Chiu
2023-02-28 22:07 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 03/19] riscv: Add new csr defines related to vector extension Andy Chiu
2023-02-28 22:31 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 04/19] riscv: Clear vector regfile on bootup Andy Chiu
2023-02-28 22:17 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 05/19] riscv: Disable Vector Instructions for kernel itself Andy Chiu
2023-02-24 17:01 ` [PATCH -next v14 06/19] riscv: Introduce Vector enable/disable helpers Andy Chiu
2023-02-28 22:36 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 07/19] riscv: Introduce riscv_v_vsize to record size of Vector context Andy Chiu
2023-02-28 22:38 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 08/19] riscv: Introduce struct/helpers to save/restore per-task Vector state Andy Chiu
2023-02-28 23:00 ` Conor Dooley
2023-03-15 4:00 ` Andy Chiu
2023-03-02 11:12 ` Björn Töpel
2023-03-15 4:05 ` Andy Chiu
2023-02-24 17:01 ` [PATCH -next v14 09/19] riscv: Add task switch support for vector Andy Chiu
2023-03-01 16:41 ` Conor Dooley
2023-03-01 16:57 ` Björn Töpel
2023-03-02 11:07 ` Björn Töpel
2023-02-24 17:01 ` [PATCH -next v14 10/19] riscv: Allocate user's vector context in the first-use trap Andy Chiu
2023-03-01 16:53 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 11/19] riscv: Add ptrace vector support Andy Chiu
2023-03-01 17:29 ` Conor Dooley
2023-03-02 11:27 ` Björn Töpel
2023-03-14 10:39 ` Andy Chiu
2023-03-14 10:44 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 12/19] riscv: signal: check fp-reserved words unconditionally Andy Chiu
2023-03-01 17:56 ` Conor Dooley [this message]
2023-02-24 17:01 ` [PATCH -next v14 13/19] riscv: signal: Add sigcontext save/restore for vector Andy Chiu
2023-03-01 18:27 ` Conor Dooley
2023-03-02 12:42 ` Björn Töpel
2023-02-24 17:01 ` [PATCH -next v14 14/19] riscv: signal: Report signal frame size to userspace via auxv Andy Chiu
2023-03-01 19:21 ` Conor Dooley
2023-03-02 12:47 ` Björn Töpel
2023-02-24 17:01 ` [PATCH -next v14 15/19] riscv: signal: validate altstack to reflect Vector Andy Chiu
2023-03-01 21:00 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 16/19] riscv: prevent stack corruption by reserving task_pt_regs(p) early Andy Chiu
2023-03-01 21:34 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 17/19] riscv: kvm: Add V extension to KVM ISA Andy Chiu
2023-03-01 21:38 ` Conor Dooley
2023-02-24 17:01 ` [PATCH -next v14 18/19] riscv: KVM: Add vector lazy save/restore support Andy Chiu
2023-02-24 17:01 ` [PATCH -next v14 19/19] riscv: Enable Vector code to be built Andy Chiu
2023-02-24 21:35 ` kernel test robot
2023-02-25 1:33 ` kernel test robot
2023-03-01 18:00 ` Nathan Chancellor
2023-03-01 18:44 ` Conor Dooley
2023-02-25 8:28 ` kernel test robot
2023-02-27 10:18 ` Conor Dooley
2023-02-27 13:40 ` Darius Rad
2023-02-27 13:58 ` Conor Dooley
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