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author | Will Deacon <will@kernel.org> | 2023-08-25 12:35:45 +0100 |
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committer | Will Deacon <will@kernel.org> | 2023-08-25 12:35:45 +0100 |
commit | cd07455764c9301a994f6dae6270853cd785ed14 (patch) | |
tree | 20d449427b0d2771dc7b4ec3da1921ba3aa28afb /arch/arm64 | |
parent | 0f4f768ffbc67e6276db8f5b1c677c21a9222542 (diff) | |
parent | f130ac0ae4412dbe4cbe32d0449a6b694b459ce6 (diff) | |
download | lwn-cd07455764c9301a994f6dae6270853cd785ed14.tar.gz lwn-cd07455764c9301a994f6dae6270853cd785ed14.zip |
Merge branch 'for-next/entry' into for-next/core
* for-next/entry:
arm64: syscall: unmask DAIF earlier for SVCs
Diffstat (limited to 'arch/arm64')
-rw-r--r-- | arch/arm64/kernel/entry-common.c | 32 | ||||
-rw-r--r-- | arch/arm64/kernel/syscall.c | 33 |
2 files changed, 32 insertions, 33 deletions
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 6b2e0c367702..0fc94207e69a 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -355,6 +355,35 @@ static bool cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) } #endif /* CONFIG_ARM64_ERRATUM_1463225 */ +/* + * As per the ABI exit SME streaming mode and clear the SVE state not + * shared with FPSIMD on syscall entry. + */ +static inline void fp_user_discard(void) +{ + /* + * If SME is active then exit streaming mode. If ZA is active + * then flush the SVE registers but leave userspace access to + * both SVE and SME enabled, otherwise disable SME for the + * task and fall through to disabling SVE too. This means + * that after a syscall we never have any streaming mode + * register state to track, if this changes the KVM code will + * need updating. + */ + if (system_supports_sme()) + sme_smstop_sm(); + + if (!system_supports_sve()) + return; + + if (test_thread_flag(TIF_SVE)) { + unsigned int sve_vq_minus_one; + + sve_vq_minus_one = sve_vq_from_vl(task_get_sve_vl(current)) - 1; + sve_flush_live(true, sve_vq_minus_one); + } +} + UNHANDLED(el1t, 64, sync) UNHANDLED(el1t, 64, irq) UNHANDLED(el1t, 64, fiq) @@ -644,6 +673,8 @@ static void noinstr el0_svc(struct pt_regs *regs) { enter_from_user_mode(regs); cortex_a76_erratum_1463225_svc_handler(); + fp_user_discard(); + local_daif_restore(DAIF_PROCCTX); do_el0_svc(regs); exit_to_user_mode(regs); } @@ -783,6 +814,7 @@ static void noinstr el0_svc_compat(struct pt_regs *regs) { enter_from_user_mode(regs); cortex_a76_erratum_1463225_svc_handler(); + local_daif_restore(DAIF_PROCCTX); do_el0_svc_compat(regs); exit_to_user_mode(regs); } diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index b1ae2f2eaf77..9a70d9746b66 100644 --- a/arch/arm64/kernel/syscall.c +++ b/arch/arm64/kernel/syscall.c @@ -8,7 +8,6 @@ #include <linux/randomize_kstack.h> #include <linux/syscalls.h> -#include <asm/daifflags.h> #include <asm/debug-monitors.h> #include <asm/exception.h> #include <asm/fpsimd.h> @@ -101,8 +100,6 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, * (Similarly for HVC and SMC elsewhere.) */ - local_daif_restore(DAIF_PROCCTX); - if (flags & _TIF_MTE_ASYNC_FAULT) { /* * Process the asynchronous tag check fault before the actual @@ -153,38 +150,8 @@ trace_exit: syscall_trace_exit(regs); } -/* - * As per the ABI exit SME streaming mode and clear the SVE state not - * shared with FPSIMD on syscall entry. - */ -static inline void fp_user_discard(void) -{ - /* - * If SME is active then exit streaming mode. If ZA is active - * then flush the SVE registers but leave userspace access to - * both SVE and SME enabled, otherwise disable SME for the - * task and fall through to disabling SVE too. This means - * that after a syscall we never have any streaming mode - * register state to track, if this changes the KVM code will - * need updating. - */ - if (system_supports_sme()) - sme_smstop_sm(); - - if (!system_supports_sve()) - return; - - if (test_thread_flag(TIF_SVE)) { - unsigned int sve_vq_minus_one; - - sve_vq_minus_one = sve_vq_from_vl(task_get_sve_vl(current)) - 1; - sve_flush_live(true, sve_vq_minus_one); - } -} - void do_el0_svc(struct pt_regs *regs) { - fp_user_discard(); el0_svc_common(regs, regs->regs[8], __NR_syscalls, sys_call_table); } |