From: Mark Brown <broonie@kernel.org> To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Shuah Khan <skhan@linuxfoundation.org>, Shuah Khan <shuah@kernel.org> Cc: Alan Hayward <alan.hayward@arm.com>, Luis Machado <luis.machado@arm.com>, Szabolcs Nagy <szabolcs.nagy@arm.com>, linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, Mark Brown <broonie@kernel.org> Subject: [PATCH v3 11/21] arm64/sme: Implement signal handling for ZT Date: Fri, 11 Nov 2022 21:50:16 +0000 [thread overview] Message-ID: <20221111215026.813348-12-broonie@kernel.org> (raw) In-Reply-To: <20221111215026.813348-1-broonie@kernel.org> Add a new signal context type for ZT which is present in the signal frame when ZA is enabled and ZT is supported by the system. In order to account for the possible addition of further ZT registers in the future we make the number of registers variable in the ABI, though currently the only possible number is 1. We could just use a bare list head for the context since the number of registers can be inferred from the size of the context but for usability and future extensibility we define a header with the number of registers and some reserved fields in it. Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/arm64/include/asm/fpsimd.h | 3 - arch/arm64/include/uapi/asm/sigcontext.h | 19 ++++ arch/arm64/kernel/signal.c | 105 +++++++++++++++++++++++ 3 files changed, 124 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 42c019936dfd..5c93cb5337c9 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -352,9 +352,6 @@ extern unsigned int sme_get_vl(void); extern int sme_set_current_vl(unsigned long arg); extern int sme_get_current_vl(void); -/* Will move with signal support */ -#define ZT_SIG_REG_SIZE 512 - /* * Return how many bytes of memory are required to store the full SME * specific state for task, given task's currently configured vector diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h index 4aaf31e3bf16..177f16cc96b8 100644 --- a/arch/arm64/include/uapi/asm/sigcontext.h +++ b/arch/arm64/include/uapi/asm/sigcontext.h @@ -148,6 +148,14 @@ struct za_context { __u16 __reserved[3]; }; +#define ZT_MAGIC 0x5a544e01 + +struct zt_context { + struct _aarch64_ctx head; + __u16 nregs; + __u16 __reserved[3]; +}; + #endif /* !__ASSEMBLY__ */ #include <asm/sve_context.h> @@ -300,4 +308,15 @@ struct za_context { #define ZA_SIG_CONTEXT_SIZE(vq) \ (ZA_SIG_REGS_OFFSET + ZA_SIG_REGS_SIZE(vq)) +#define ZT_SIG_REG_SIZE 512 + +#define ZT_SIG_REG_BYTES (ZT_SIG_REG_SIZE / 8) + +#define ZT_SIG_REGS_OFFSET sizeof(struct zt_context) + +#define ZT_SIG_REGS_SIZE(n) (ZT_SIG_REG_BYTES * n) + +#define ZT_SIG_CONTEXT_SIZE(n) \ + (sizeof(struct zt_context) + ZT_SIG_REGS_SIZE(n)) + #endif /* _UAPI__ASM_SIGCONTEXT_H */ diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 335bc7294b3c..6e20f0b23d73 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -57,6 +57,7 @@ struct rt_sigframe_user_layout { unsigned long esr_offset; unsigned long sve_offset; unsigned long za_offset; + unsigned long zt_offset; unsigned long extra_offset; unsigned long end_offset; }; @@ -220,6 +221,7 @@ struct user_ctxs { struct fpsimd_context __user *fpsimd; struct sve_context __user *sve; struct za_context __user *za; + struct zt_context __user *zt; }; #ifdef CONFIG_ARM64_SVE @@ -444,11 +446,81 @@ static int restore_za_context(struct user_ctxs *user) return 0; } + +static int preserve_zt_context(struct zt_context __user *ctx) +{ + int err = 0; + u16 reserved[ARRAY_SIZE(ctx->__reserved)]; + + if (WARN_ON(!thread_za_enabled(¤t->thread))) + return -EINVAL; + + memset(reserved, 0, sizeof(reserved)); + + __put_user_error(ZT_MAGIC, &ctx->head.magic, err); + __put_user_error(round_up(ZT_SIG_CONTEXT_SIZE(1), 16), + &ctx->head.size, err); + __put_user_error(1, &ctx->nregs, err); + BUILD_BUG_ON(sizeof(ctx->__reserved) != sizeof(reserved)); + err |= __copy_to_user(&ctx->__reserved, reserved, sizeof(reserved)); + + /* + * This assumes that the ZT state has already been saved to + * the task struct by calling the function + * fpsimd_signal_preserve_current_state(). + */ + err |= __copy_to_user((char __user *)ctx + ZT_SIG_REGS_OFFSET, + thread_zt_state(¤t->thread), + ZT_SIG_REGS_SIZE(1)); + + return err ? -EFAULT : 0; +} + +static int restore_zt_context(struct user_ctxs *user) +{ + int err; + struct zt_context zt; + + /* ZA must be restored first for this check to be valid */ + if (!thread_za_enabled(¤t->thread)) + return -EINVAL; + + if (__copy_from_user(&zt, user->zt, sizeof(zt))) + return -EFAULT; + + if (zt.nregs != 1) + return -EINVAL; + + if (zt.head.size != ZT_SIG_CONTEXT_SIZE(zt.nregs)) + return -EINVAL; + + /* + * Careful: we are about __copy_from_user() directly into + * thread.zt_state with preemption enabled, so protection is + * needed to prevent a racing context switch from writing stale + * registers back over the new data. + */ + + fpsimd_flush_task_state(current); + /* From now, fpsimd_thread_switch() won't touch ZT in thread state */ + + err = __copy_from_user(thread_zt_state(¤t->thread), + (char __user const *)user->zt + + ZT_SIG_REGS_OFFSET, + ZT_SIG_REGS_SIZE(1)); + if (err) + return -EFAULT; + + return 0; +} + #else /* ! CONFIG_ARM64_SME */ /* Turn any non-optimised out attempts to use these into a link error: */ extern int preserve_za_context(void __user *ctx); extern int restore_za_context(struct user_ctxs *user); +extern int preserve_zt_context(void __user *ctx); +extern int restore_zt_context(struct user_ctxs *user); #endif /* ! CONFIG_ARM64_SME */ @@ -466,6 +538,7 @@ static int parse_user_sigframe(struct user_ctxs *user, user->fpsimd = NULL; user->sve = NULL; user->za = NULL; + user->zt = NULL; if (!IS_ALIGNED((unsigned long)base, 16)) goto invalid; @@ -544,6 +617,19 @@ static int parse_user_sigframe(struct user_ctxs *user, user->za = (struct za_context __user *)head; break; + case ZT_MAGIC: + if (!system_supports_sme2()) + goto invalid; + + if (user->zt) + goto invalid; + + if (size < sizeof(*user->zt)) + goto invalid; + + user->zt = (struct zt_context __user *)head; + break; + case EXTRA_MAGIC: if (have_extra_context) goto invalid; @@ -666,6 +752,9 @@ static int restore_sigframe(struct pt_regs *regs, if (err == 0 && system_supports_sme() && user.za) err = restore_za_context(&user); + if (err == 0 && system_supports_sme2() && user.zt) + err = restore_zt_context(&user); + return err; } @@ -766,6 +855,15 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user, return err; } + if (system_supports_sme2()) { + if (add_all || thread_za_enabled(¤t->thread)) { + err = sigframe_alloc(user, &user->zt_offset, + ZT_SIG_CONTEXT_SIZE(1)); + if (err) + return err; + } + } + return sigframe_alloc_end(user); } @@ -821,6 +919,13 @@ static int setup_sigframe(struct rt_sigframe_user_layout *user, err |= preserve_za_context(za_ctx); } + /* ZT state if present */ + if (system_supports_sme2() && err == 0 && user->zt_offset) { + struct zt_context __user *zt_ctx = + apply_user_offset(user, user->zt_offset); + err |= preserve_zt_context(zt_ctx); + } + if (err == 0 && user->extra_offset) { char __user *sfp = (char __user *)user->sigframe; char __user *userp = -- 2.30.2
WARNING: multiple messages have this Message-ID (diff)
From: Mark Brown <broonie@kernel.org> To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Shuah Khan <skhan@linuxfoundation.org>, Shuah Khan <shuah@kernel.org> Cc: Alan Hayward <alan.hayward@arm.com>, Luis Machado <luis.machado@arm.com>, Szabolcs Nagy <szabolcs.nagy@arm.com>, linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, Mark Brown <broonie@kernel.org> Subject: [PATCH v3 11/21] arm64/sme: Implement signal handling for ZT Date: Fri, 11 Nov 2022 21:50:16 +0000 [thread overview] Message-ID: <20221111215026.813348-12-broonie@kernel.org> (raw) In-Reply-To: <20221111215026.813348-1-broonie@kernel.org> Add a new signal context type for ZT which is present in the signal frame when ZA is enabled and ZT is supported by the system. In order to account for the possible addition of further ZT registers in the future we make the number of registers variable in the ABI, though currently the only possible number is 1. We could just use a bare list head for the context since the number of registers can be inferred from the size of the context but for usability and future extensibility we define a header with the number of registers and some reserved fields in it. Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/arm64/include/asm/fpsimd.h | 3 - arch/arm64/include/uapi/asm/sigcontext.h | 19 ++++ arch/arm64/kernel/signal.c | 105 +++++++++++++++++++++++ 3 files changed, 124 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 42c019936dfd..5c93cb5337c9 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -352,9 +352,6 @@ extern unsigned int sme_get_vl(void); extern int sme_set_current_vl(unsigned long arg); extern int sme_get_current_vl(void); -/* Will move with signal support */ -#define ZT_SIG_REG_SIZE 512 - /* * Return how many bytes of memory are required to store the full SME * specific state for task, given task's currently configured vector diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h index 4aaf31e3bf16..177f16cc96b8 100644 --- a/arch/arm64/include/uapi/asm/sigcontext.h +++ b/arch/arm64/include/uapi/asm/sigcontext.h @@ -148,6 +148,14 @@ struct za_context { __u16 __reserved[3]; }; +#define ZT_MAGIC 0x5a544e01 + +struct zt_context { + struct _aarch64_ctx head; + __u16 nregs; + __u16 __reserved[3]; +}; + #endif /* !__ASSEMBLY__ */ #include <asm/sve_context.h> @@ -300,4 +308,15 @@ struct za_context { #define ZA_SIG_CONTEXT_SIZE(vq) \ (ZA_SIG_REGS_OFFSET + ZA_SIG_REGS_SIZE(vq)) +#define ZT_SIG_REG_SIZE 512 + +#define ZT_SIG_REG_BYTES (ZT_SIG_REG_SIZE / 8) + +#define ZT_SIG_REGS_OFFSET sizeof(struct zt_context) + +#define ZT_SIG_REGS_SIZE(n) (ZT_SIG_REG_BYTES * n) + +#define ZT_SIG_CONTEXT_SIZE(n) \ + (sizeof(struct zt_context) + ZT_SIG_REGS_SIZE(n)) + #endif /* _UAPI__ASM_SIGCONTEXT_H */ diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 335bc7294b3c..6e20f0b23d73 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -57,6 +57,7 @@ struct rt_sigframe_user_layout { unsigned long esr_offset; unsigned long sve_offset; unsigned long za_offset; + unsigned long zt_offset; unsigned long extra_offset; unsigned long end_offset; }; @@ -220,6 +221,7 @@ struct user_ctxs { struct fpsimd_context __user *fpsimd; struct sve_context __user *sve; struct za_context __user *za; + struct zt_context __user *zt; }; #ifdef CONFIG_ARM64_SVE @@ -444,11 +446,81 @@ static int restore_za_context(struct user_ctxs *user) return 0; } + +static int preserve_zt_context(struct zt_context __user *ctx) +{ + int err = 0; + u16 reserved[ARRAY_SIZE(ctx->__reserved)]; + + if (WARN_ON(!thread_za_enabled(¤t->thread))) + return -EINVAL; + + memset(reserved, 0, sizeof(reserved)); + + __put_user_error(ZT_MAGIC, &ctx->head.magic, err); + __put_user_error(round_up(ZT_SIG_CONTEXT_SIZE(1), 16), + &ctx->head.size, err); + __put_user_error(1, &ctx->nregs, err); + BUILD_BUG_ON(sizeof(ctx->__reserved) != sizeof(reserved)); + err |= __copy_to_user(&ctx->__reserved, reserved, sizeof(reserved)); + + /* + * This assumes that the ZT state has already been saved to + * the task struct by calling the function + * fpsimd_signal_preserve_current_state(). + */ + err |= __copy_to_user((char __user *)ctx + ZT_SIG_REGS_OFFSET, + thread_zt_state(¤t->thread), + ZT_SIG_REGS_SIZE(1)); + + return err ? -EFAULT : 0; +} + +static int restore_zt_context(struct user_ctxs *user) +{ + int err; + struct zt_context zt; + + /* ZA must be restored first for this check to be valid */ + if (!thread_za_enabled(¤t->thread)) + return -EINVAL; + + if (__copy_from_user(&zt, user->zt, sizeof(zt))) + return -EFAULT; + + if (zt.nregs != 1) + return -EINVAL; + + if (zt.head.size != ZT_SIG_CONTEXT_SIZE(zt.nregs)) + return -EINVAL; + + /* + * Careful: we are about __copy_from_user() directly into + * thread.zt_state with preemption enabled, so protection is + * needed to prevent a racing context switch from writing stale + * registers back over the new data. + */ + + fpsimd_flush_task_state(current); + /* From now, fpsimd_thread_switch() won't touch ZT in thread state */ + + err = __copy_from_user(thread_zt_state(¤t->thread), + (char __user const *)user->zt + + ZT_SIG_REGS_OFFSET, + ZT_SIG_REGS_SIZE(1)); + if (err) + return -EFAULT; + + return 0; +} + #else /* ! CONFIG_ARM64_SME */ /* Turn any non-optimised out attempts to use these into a link error: */ extern int preserve_za_context(void __user *ctx); extern int restore_za_context(struct user_ctxs *user); +extern int preserve_zt_context(void __user *ctx); +extern int restore_zt_context(struct user_ctxs *user); #endif /* ! CONFIG_ARM64_SME */ @@ -466,6 +538,7 @@ static int parse_user_sigframe(struct user_ctxs *user, user->fpsimd = NULL; user->sve = NULL; user->za = NULL; + user->zt = NULL; if (!IS_ALIGNED((unsigned long)base, 16)) goto invalid; @@ -544,6 +617,19 @@ static int parse_user_sigframe(struct user_ctxs *user, user->za = (struct za_context __user *)head; break; + case ZT_MAGIC: + if (!system_supports_sme2()) + goto invalid; + + if (user->zt) + goto invalid; + + if (size < sizeof(*user->zt)) + goto invalid; + + user->zt = (struct zt_context __user *)head; + break; + case EXTRA_MAGIC: if (have_extra_context) goto invalid; @@ -666,6 +752,9 @@ static int restore_sigframe(struct pt_regs *regs, if (err == 0 && system_supports_sme() && user.za) err = restore_za_context(&user); + if (err == 0 && system_supports_sme2() && user.zt) + err = restore_zt_context(&user); + return err; } @@ -766,6 +855,15 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user, return err; } + if (system_supports_sme2()) { + if (add_all || thread_za_enabled(¤t->thread)) { + err = sigframe_alloc(user, &user->zt_offset, + ZT_SIG_CONTEXT_SIZE(1)); + if (err) + return err; + } + } + return sigframe_alloc_end(user); } @@ -821,6 +919,13 @@ static int setup_sigframe(struct rt_sigframe_user_layout *user, err |= preserve_za_context(za_ctx); } + /* ZT state if present */ + if (system_supports_sme2() && err == 0 && user->zt_offset) { + struct zt_context __user *zt_ctx = + apply_user_offset(user, user->zt_offset); + err |= preserve_zt_context(zt_ctx); + } + if (err == 0 && user->extra_offset) { char __user *sfp = (char __user *)user->sigframe; char __user *userp = -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-11-11 21:51 UTC|newest] Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-11-11 21:50 [PATCH v3 00/21] arm64/sme: Support SME 2 and SME 2.1 Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 01/21] arm64/sme: Rename za_state to sme_state Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 02/21] arm64: Document boot requirements for SME 2 Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 03/21] arm64/sysreg: Update system registers for SME 2 and 2.1 Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 04/21] arm64/sme: Document SME 2 and SME 2.1 ABI Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 05/21] arm64/esr: Document ISS for ZT0 being disabled Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 06/21] arm64/sme: Manually encode ZT0 load and store instructions Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-12-17 9:40 ` Zenghui Yu 2022-12-17 9:40 ` Zenghui Yu 2022-12-19 15:04 ` Mark Brown 2022-12-19 15:04 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 07/21] arm64/sme: Enable host kernel to access ZT0 Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 08/21] arm64/sme: Add basic enumeration for SME2 Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 09/21] arm64/sme: Provide storage for ZT0 Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-12-17 9:28 ` Zenghui Yu 2022-12-17 9:28 ` Zenghui Yu 2022-11-11 21:50 ` [PATCH v3 10/21] arm64/sme: Implement context switching " Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` Mark Brown [this message] 2022-11-11 21:50 ` [PATCH v3 11/21] arm64/sme: Implement signal handling for ZT Mark Brown 2022-11-11 21:50 ` [PATCH v3 12/21] arm64/sme: Implement ZT0 ptrace support Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-12-17 9:23 ` Zenghui Yu 2022-12-17 9:23 ` Zenghui Yu 2022-11-11 21:50 ` [PATCH v3 13/21] arm64/sme: Add hwcaps for SME 2 and 2.1 features Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-12-19 8:22 ` Zenghui Yu 2022-12-19 8:22 ` Zenghui Yu 2022-11-11 21:50 ` [PATCH v3 14/21] kselftest/arm64: Add a stress test program for ZT0 Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-12-17 9:15 ` Zenghui Yu 2022-12-17 9:15 ` Zenghui Yu 2022-11-11 21:50 ` [PATCH v3 15/21] kselftest/arm64: Cover ZT in the FP stress test Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 16/21] kselftest/arm64: Enumerate SME2 in the signal test utility code Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 17/21] kselftest/arm64: Teach the generic signal context validation about ZT Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 18/21] kselftest/arm64: Add test coverage for ZT register signal frames Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 19/21] kselftest/arm64: Add SME2 coverage to syscall-abi Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 20/21] kselftest/arm64: Add coverage of the ZT ptrace regset Mark Brown 2022-11-11 21:50 ` Mark Brown 2022-11-11 21:50 ` [PATCH v3 21/21] kselftest/arm64: Add coverage of SME 2 and 2.1 hwcaps Mark Brown 2022-11-11 21:50 ` Mark Brown
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