diff options
Diffstat (limited to 'arch/arm64/kernel/syscall.c')
| -rw-r--r-- | arch/arm64/kernel/syscall.c | 58 |
1 files changed, 2 insertions, 56 deletions
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index 733451fe7e41..ad198262b981 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> @@ -21,14 +20,11 @@ long sys_ni_syscall(void); static long do_ni_syscall(struct pt_regs *regs, int scno) { -#ifdef CONFIG_COMPAT - long ret; if (is_compat_task()) { - ret = compat_arm_syscall(regs, scno); + long ret = compat_arm_syscall(regs, scno); if (ret != -ENOSYS) return ret; } -#endif return sys_ni_syscall(); } @@ -67,7 +63,7 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno, * * The resulting 5 bits of entropy is seen in SP[8:4]. */ - choose_random_kstack_offset(get_random_int() & 0x1FF); + choose_random_kstack_offset(get_random_u16() & 0x1FF); } static inline bool has_syscall_work(unsigned long flags) @@ -75,9 +71,6 @@ static inline bool has_syscall_work(unsigned long flags) return unlikely(flags & _TIF_SYSCALL_WORK); } -int syscall_trace_enter(struct pt_regs *regs); -void syscall_trace_exit(struct pt_regs *regs); - static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, const syscall_fn_t syscall_table[]) { @@ -104,8 +97,6 @@ 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 @@ -147,62 +138,17 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, * exit regardless, as the old entry assembly did. */ if (!has_syscall_work(flags) && !IS_ENABLED(CONFIG_DEBUG_RSEQ)) { - local_daif_mask(); flags = read_thread_flags(); if (!has_syscall_work(flags) && !(flags & _TIF_SINGLESTEP)) return; - local_daif_restore(DAIF_PROCCTX); } 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() && test_thread_flag(TIF_SME)) { - u64 svcr = read_sysreg_s(SYS_SVCR); - - if (svcr & SVCR_SM_MASK) - sme_smstop_sm(); - } - - if (!system_supports_sve()) - return; - - /* - * If SME is not active then disable SVE, the registers will - * be cleared when userspace next attempts to access them and - * we do not need to track the SVE register state until then. - */ - clear_thread_flag(TIF_SVE); - - /* - * task_fpsimd_load() won't be called to update CPACR_EL1 in - * ret_to_user unless TIF_FOREIGN_FPSTATE is still set, which only - * happens if a context switch or kernel_neon_begin() or context - * modification (sigreturn, ptrace) intervenes. - * So, ensure that CPACR_EL1 is already correct for the fast-path case. - */ - sve_user_disable(); -} - void do_el0_svc(struct pt_regs *regs) { - fp_user_discard(); el0_svc_common(regs, regs->regs[8], __NR_syscalls, sys_call_table); } |