From patchwork Fri Oct 27 18:08:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joey Gouly X-Patchwork-Id: 13438761 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CAE033CD04 for ; Fri, 27 Oct 2023 18:09:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 264F5AC; Fri, 27 Oct 2023 11:09:41 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 795911424; Fri, 27 Oct 2023 11:10:22 -0700 (PDT) Received: from e124191.cambridge.arm.com (e124191.cambridge.arm.com [10.1.197.45]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id ABCE63F64C; Fri, 27 Oct 2023 11:09:38 -0700 (PDT) From: Joey Gouly To: linux-arm-kernel@lists.infradead.org Cc: akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, broonie@kernel.org, catalin.marinas@arm.com, dave.hansen@linux.intel.com, joey.gouly@arm.com, maz@kernel.org, oliver.upton@linux.dev, shuah@kernel.org, will@kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, James Morse , Suzuki K Poulose , Zenghui Yu Subject: [PATCH v2 15/24] arm64: add POE signal support Date: Fri, 27 Oct 2023 19:08:41 +0100 Message-Id: <20231027180850.1068089-16-joey.gouly@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231027180850.1068089-1-joey.gouly@arm.com> References: <20231027180850.1068089-1-joey.gouly@arm.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add PKEY support to signals, by saving and restoring POR_EL0 from the stackframe. Signed-off-by: Joey Gouly Cc: Catalin Marinas Cc: Will Deacon Reviewed-by: Mark Brown --- arch/arm64/include/uapi/asm/sigcontext.h | 7 ++++ arch/arm64/kernel/signal.c | 51 ++++++++++++++++++++++++ 2 files changed, 58 insertions(+) diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h index f23c1dc3f002..cef85eeaf541 100644 --- a/arch/arm64/include/uapi/asm/sigcontext.h +++ b/arch/arm64/include/uapi/asm/sigcontext.h @@ -98,6 +98,13 @@ struct esr_context { __u64 esr; }; +#define POE_MAGIC 0x504f4530 + +struct poe_context { + struct _aarch64_ctx head; + __u64 por_el0; +}; + /* * extra_context: describes extra space in the signal frame for * additional structures that don't fit in sigcontext.__reserved[]. diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 0e8beb3349ea..379f364005bf 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -62,6 +62,7 @@ struct rt_sigframe_user_layout { unsigned long zt_offset; unsigned long extra_offset; unsigned long end_offset; + unsigned long poe_offset; }; #define BASE_SIGFRAME_SIZE round_up(sizeof(struct rt_sigframe), 16) @@ -182,6 +183,8 @@ struct user_ctxs { u32 za_size; struct zt_context __user *zt; u32 zt_size; + struct poe_context __user *poe; + u32 poe_size; }; static int preserve_fpsimd_context(struct fpsimd_context __user *ctx) @@ -227,6 +230,20 @@ static int restore_fpsimd_context(struct user_ctxs *user) return err ? -EFAULT : 0; } +static int restore_poe_context(struct user_ctxs *user) +{ + u64 por_el0; + int err = 0; + + if (user->poe_size != sizeof(*user->poe)) + return -EINVAL; + + __get_user_error(por_el0, &(user->poe->por_el0), err); + if (!err) + write_sysreg_s(por_el0, SYS_POR_EL0); + + return err; +} #ifdef CONFIG_ARM64_SVE @@ -590,6 +607,7 @@ static int parse_user_sigframe(struct user_ctxs *user, user->tpidr2 = NULL; user->za = NULL; user->zt = NULL; + user->poe = NULL; if (!IS_ALIGNED((unsigned long)base, 16)) goto invalid; @@ -640,6 +658,17 @@ static int parse_user_sigframe(struct user_ctxs *user, /* ignore */ break; + case POE_MAGIC: + if (!system_supports_poe()) + goto invalid; + + if (user->poe) + goto invalid; + + user->poe = (struct poe_context __user *)head; + user->poe_size = size; + break; + case SVE_MAGIC: if (!system_supports_sve() && !system_supports_sme()) goto invalid; @@ -812,6 +841,9 @@ static int restore_sigframe(struct pt_regs *regs, if (err == 0 && system_supports_sme2() && user.zt) err = restore_zt_context(&user); + if (err == 0 && system_supports_poe() && user.poe) + err = restore_poe_context(&user); + return err; } @@ -928,6 +960,13 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user, } } + if (system_supports_poe()) { + err = sigframe_alloc(user, &user->poe_offset, + sizeof(struct poe_context)); + if (err) + return err; + } + return sigframe_alloc_end(user); } @@ -968,6 +1007,15 @@ static int setup_sigframe(struct rt_sigframe_user_layout *user, __put_user_error(current->thread.fault_code, &esr_ctx->esr, err); } + if (system_supports_poe() && err == 0 && user->poe_offset) { + struct poe_context __user *poe_ctx = + apply_user_offset(user, user->poe_offset); + + __put_user_error(POE_MAGIC, &poe_ctx->head.magic, err); + __put_user_error(sizeof(*poe_ctx), &poe_ctx->head.size, err); + __put_user_error(read_sysreg_s(SYS_POR_EL0), &poe_ctx->por_el0, err); + } + /* Scalable Vector Extension state (including streaming), if present */ if ((system_supports_sve() || system_supports_sme()) && err == 0 && user->sve_offset) { @@ -1119,6 +1167,9 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka, sme_smstop(); } + if (system_supports_poe()) + write_sysreg_s(POR_EL0_INIT, SYS_POR_EL0); + if (ka->sa.sa_flags & SA_RESTORER) sigtramp = ka->sa.sa_restorer; else