diff options
| -rw-r--r-- | Documentation/arm64/sme.rst | 3 | ||||
| -rw-r--r-- | arch/arm64/include/uapi/asm/sigcontext.h | 8 | ||||
| -rw-r--r-- | arch/arm64/kernel/signal.c | 59 | ||||
| -rw-r--r-- | tools/testing/selftests/arm64/signal/.gitignore | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/arm64/signal/testcases/testcases.c | 4 | ||||
| -rw-r--r-- | tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c | 90 |
6 files changed, 165 insertions, 0 deletions
diff --git a/Documentation/arm64/sme.rst b/Documentation/arm64/sme.rst index 68d1efb7d171..1c43ea12eb4f 100644 --- a/Documentation/arm64/sme.rst +++ b/Documentation/arm64/sme.rst @@ -117,6 +117,9 @@ be zeroed. * Signal handlers are invoked with streaming mode and ZA disabled. +* A new signal frame record TPIDR2_MAGIC is added formatted as a struct + tpidr2_context to allow access to TPIDR2_EL0 from signal handlers. + * A new signal frame record za_context encodes the ZA register contents on signal delivery. [1] diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h index 46e9072985a5..656a10ea6c67 100644 --- a/arch/arm64/include/uapi/asm/sigcontext.h +++ b/arch/arm64/include/uapi/asm/sigcontext.h @@ -144,6 +144,14 @@ struct sve_context { #define SVE_SIG_FLAG_SM 0x1 /* Context describes streaming mode */ +/* TPIDR2_EL0 context */ +#define TPIDR2_MAGIC 0x54504902 + +struct tpidr2_context { + struct _aarch64_ctx head; + __u64 tpidr2; +}; + #define ZA_MAGIC 0x54366345 struct za_context { diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 1c5e557a3617..ed692284f199 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -56,6 +56,7 @@ struct rt_sigframe_user_layout { unsigned long fpsimd_offset; unsigned long esr_offset; unsigned long sve_offset; + unsigned long tpidr2_offset; unsigned long za_offset; unsigned long zt_offset; unsigned long extra_offset; @@ -221,6 +222,7 @@ static int restore_fpsimd_context(struct fpsimd_context __user *ctx) struct user_ctxs { struct fpsimd_context __user *fpsimd; struct sve_context __user *sve; + struct tpidr2_context __user *tpidr2; struct za_context __user *za; struct zt_context __user *zt; }; @@ -363,6 +365,32 @@ extern int preserve_sve_context(void __user *ctx); #ifdef CONFIG_ARM64_SME +static int preserve_tpidr2_context(struct tpidr2_context __user *ctx) +{ + int err = 0; + + current->thread.tpidr2_el0 = read_sysreg_s(SYS_TPIDR2_EL0); + + __put_user_error(TPIDR2_MAGIC, &ctx->head.magic, err); + __put_user_error(sizeof(*ctx), &ctx->head.size, err); + __put_user_error(current->thread.tpidr2_el0, &ctx->tpidr2, err); + + return err; +} + +static int restore_tpidr2_context(struct user_ctxs *user) +{ + u64 tpidr2_el0; + int err = 0; + + /* Magic and size were validated deciding to call this function */ + __get_user_error(tpidr2_el0, &user->tpidr2->tpidr2, err); + if (!err) + current->thread.tpidr2_el0 = tpidr2_el0; + + return err; +} + static int preserve_za_context(struct za_context __user *ctx) { int err = 0; @@ -520,6 +548,8 @@ static int restore_zt_context(struct user_ctxs *user) #else /* ! CONFIG_ARM64_SME */ /* Turn any non-optimised out attempts to use these into a link error: */ +extern int preserve_tpidr2_context(void __user *ctx); +extern int restore_tpidr2_context(struct user_ctxs *user); 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); @@ -540,6 +570,7 @@ static int parse_user_sigframe(struct user_ctxs *user, user->fpsimd = NULL; user->sve = NULL; + user->tpidr2 = NULL; user->za = NULL; user->zt = NULL; @@ -607,6 +638,19 @@ static int parse_user_sigframe(struct user_ctxs *user, user->sve = (struct sve_context __user *)head; break; + case TPIDR2_MAGIC: + if (!system_supports_sme()) + goto invalid; + + if (user->tpidr2) + goto invalid; + + if (size != sizeof(*user->tpidr2)) + goto invalid; + + user->tpidr2 = (struct tpidr2_context __user *)head; + break; + case ZA_MAGIC: if (!system_supports_sme()) goto invalid; @@ -752,6 +796,9 @@ static int restore_sigframe(struct pt_regs *regs, err = restore_fpsimd_context(user.fpsimd); } + if (err == 0 && system_supports_sme() && user.tpidr2) + err = restore_tpidr2_context(&user); + if (err == 0 && system_supports_sme() && user.za) err = restore_za_context(&user); @@ -849,6 +896,11 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user, else vl = task_get_sme_vl(current); + err = sigframe_alloc(user, &user->tpidr2_offset, + sizeof(struct tpidr2_context)); + if (err) + return err; + if (thread_za_enabled(¤t->thread)) vq = sve_vq_from_vl(vl); @@ -915,6 +967,13 @@ static int setup_sigframe(struct rt_sigframe_user_layout *user, err |= preserve_sve_context(sve_ctx); } + /* TPIDR2 if supported */ + if (system_supports_sme() && err == 0) { + struct tpidr2_context __user *tpidr2_ctx = + apply_user_offset(user, user->tpidr2_offset); + err |= preserve_tpidr2_context(tpidr2_ctx); + } + /* ZA state if present */ if (system_supports_sme() && err == 0 && user->za_offset) { struct za_context __user *za_ctx = diff --git a/tools/testing/selftests/arm64/signal/.gitignore b/tools/testing/selftests/arm64/signal/.gitignore index b7fbb65183e8..8ab4c86837fd 100644 --- a/tools/testing/selftests/arm64/signal/.gitignore +++ b/tools/testing/selftests/arm64/signal/.gitignore @@ -4,6 +4,7 @@ fake_sigreturn_* sme_* ssve_* sve_* +tpidr2_siginfo za_* zt_* !*.[ch] diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.c b/tools/testing/selftests/arm64/signal/testcases/testcases.c index 27d495fa52f8..9f580b55b388 100644 --- a/tools/testing/selftests/arm64/signal/testcases/testcases.c +++ b/tools/testing/selftests/arm64/signal/testcases/testcases.c @@ -184,6 +184,10 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err) if (head->size != sizeof(struct esr_context)) *err = "Bad size for esr_context"; break; + case TPIDR2_MAGIC: + if (head->size != sizeof(struct tpidr2_context)) + *err = "Bad size for tpidr2_context"; + break; case SVE_MAGIC: if (flags & SVE_CTX) *err = "Multiple SVE_MAGIC"; diff --git a/tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c b/tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c new file mode 100644 index 000000000000..6a2c82bf7ead --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2022 ARM Limited + * + * Verify that the TPIDR2 register context in signal frames is set up as + * expected. + */ + +#include <signal.h> +#include <ucontext.h> +#include <sys/auxv.h> +#include <sys/prctl.h> +#include <unistd.h> +#include <asm/sigcontext.h> + +#include "test_signals_utils.h" +#include "testcases.h" + +static union { + ucontext_t uc; + char buf[1024 * 128]; +} context; + +#define SYS_TPIDR2 "S3_3_C13_C0_5" + +static uint64_t get_tpidr2(void) +{ + uint64_t val; + + asm volatile ( + "mrs %0, " SYS_TPIDR2 "\n" + : "=r"(val) + : + : "cc"); + + return val; +} + +int tpidr2_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc) +{ + struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context); + struct tpidr2_context *tpidr2_ctx; + size_t offset; + bool in_sigframe; + bool have_sme; + __u64 orig_tpidr2; + + have_sme = getauxval(AT_HWCAP2) & HWCAP2_SME; + if (have_sme) + orig_tpidr2 = get_tpidr2(); + + if (!get_current_context(td, &context.uc, sizeof(context))) + return 1; + + tpidr2_ctx = (struct tpidr2_context *) + get_header(head, TPIDR2_MAGIC, td->live_sz, &offset); + + in_sigframe = tpidr2_ctx != NULL; + + fprintf(stderr, "TPIDR2 sigframe %s on system %s SME\n", + in_sigframe ? "present" : "absent", + have_sme ? "with" : "without"); + + td->pass = (in_sigframe == have_sme); + + /* + * Check that the value we read back was the one present at + * the time that the signal was triggered. TPIDR2 is owned by + * libc so we can't safely choose the value and it is possible + * that we may need to revisit this in future if something + * starts deciding to set a new TPIDR2 between us reading and + * the signal. + */ + if (have_sme && tpidr2_ctx) { + if (tpidr2_ctx->tpidr2 != orig_tpidr2) { + fprintf(stderr, "TPIDR2 in frame is %llx, was %llx\n", + tpidr2_ctx->tpidr2, orig_tpidr2); + td->pass = false; + } + } + + return 0; +} + +struct tdescr tde = { + .name = "TPIDR2", + .descr = "Validate that TPIDR2 is present as expected", + .timeout = 3, + .run = tpidr2_present, +}; |