From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2EADE25763 for ; Mon, 22 Jul 2024 09:16:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721639783; cv=none; b=PYueauVzoCp7itVkNeW8IXfNUYpe6xdy0jYdVQJTVC/lseVz8WmGAgoUr1rQTYJ49ytSANokSHpq/nuYyjWZTF5BTR9CpQT5NrtOwRF3RMOJ56kPTq6YWc8qNj/KtreCnpAKmy0Ja1Af1XlieDAPJviLdjk6Jcf/T8OphS2hN9o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721639783; c=relaxed/simple; bh=7C/drCaoNFVEaUE441qDvzta0bNUQ/yAp+86vRAao00=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=FDqiqlyYZPZYOlkErEwcDaUf9VmbPQ7T/aPnj/3W+8ynu7Y64gke9MWiHobbGz/xX0jMmRr6BgrkkzLVGfSbXWlUK+ZRY1NIl2y2putewOc2/AFDwJEzJxN+DNSqK0fyBJQseoCkgvee4UNCP89kpWsvBdYmu4FPPpO+GWC+pGA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 CF5ADFEC; Mon, 22 Jul 2024 02:16:45 -0700 (PDT) Received: from [10.162.41.8] (a077893.blr.arm.com [10.162.41.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 71F823F766; Mon, 22 Jul 2024 02:16:12 -0700 (PDT) Message-ID: <3c385faa-bfe9-4731-8fdc-fa786f2160df@arm.com> Date: Mon, 22 Jul 2024 14:46:09 +0530 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 18/29] arm64: add POE signal support To: Joey Gouly , linux-arm-kernel@lists.infradead.org Cc: akpm@linux-foundation.org, aneesh.kumar@kernel.org, aneesh.kumar@linux.ibm.com, bp@alien8.de, broonie@kernel.org, catalin.marinas@arm.com, christophe.leroy@csgroup.eu, dave.hansen@linux.intel.com, hpa@zytor.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, maz@kernel.org, mingo@redhat.com, mpe@ellerman.id.au, naveen.n.rao@linux.ibm.com, npiggin@gmail.com, oliver.upton@linux.dev, shuah@kernel.org, szabolcs.nagy@arm.com, tglx@linutronix.de, will@kernel.org, x86@kernel.org, kvmarm@lists.linux.dev References: <20240503130147.1154804-1-joey.gouly@arm.com> <20240503130147.1154804-19-joey.gouly@arm.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20240503130147.1154804-19-joey.gouly@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/3/24 18:31, Joey Gouly wrote: > 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 > Acked-by: Szabolcs Nagy Reviewed-by: Anshuman Khandual > --- > arch/arm64/include/uapi/asm/sigcontext.h | 7 ++++ > arch/arm64/kernel/signal.c | 52 ++++++++++++++++++++++++ > 2 files changed, 59 insertions(+) > > diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h > index 8a45b7a411e0..e4cba8a6c9a2 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 4a77f4976e11..077436a8bc10 100644 > --- a/arch/arm64/kernel/signal.c > +++ b/arch/arm64/kernel/signal.c > @@ -63,6 +63,7 @@ struct rt_sigframe_user_layout { > unsigned long fpmr_offset; > unsigned long extra_offset; > unsigned long end_offset; > + unsigned long poe_offset; > }; > > #define BASE_SIGFRAME_SIZE round_up(sizeof(struct rt_sigframe), 16) > @@ -185,6 +186,8 @@ struct user_ctxs { > u32 zt_size; > struct fpmr_context __user *fpmr; > u32 fpmr_size; > + struct poe_context __user *poe; > + u32 poe_size; > }; > > static int preserve_fpsimd_context(struct fpsimd_context __user *ctx) > @@ -258,6 +261,21 @@ static int restore_fpmr_context(struct user_ctxs *user) > return err; > } > > +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 > > static int preserve_sve_context(struct sve_context __user *ctx) > @@ -621,6 +639,7 @@ static int parse_user_sigframe(struct user_ctxs *user, > user->za = NULL; > user->zt = NULL; > user->fpmr = NULL; > + user->poe = NULL; > > if (!IS_ALIGNED((unsigned long)base, 16)) > goto invalid; > @@ -671,6 +690,17 @@ 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; > @@ -857,6 +887,9 @@ 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; > } > > @@ -980,6 +1013,13 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user, > return err; > } > > + if (system_supports_poe()) { > + err = sigframe_alloc(user, &user->poe_offset, > + sizeof(struct poe_context)); > + if (err) > + return err; > + } > + > return sigframe_alloc_end(user); > } > > @@ -1020,6 +1060,15 @@ 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) { > @@ -1178,6 +1227,9 @@ 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