Replace the syscall exit handling code with the generic version. That gets rid of the interrupts disabled check for work flags. That's a non-issue because the flags are checked with READ_ONCE() in the core and not reevaluated. That's perfectly fine because the interrupts disabled check is also just a snapshot.
Signed-off-by: Thomas Gleixner <[email protected]> --- arch/arm64/include/asm/entry-common.h | 11 +++++++++ arch/arm64/kernel/ptrace.c | 38 ---------------------------------- arch/arm64/kernel/syscall.c | 14 ------------ 3 files changed, 12 insertions(+), 51 deletions(-) --- a/arch/arm64/include/asm/entry-common.h +++ b/arch/arm64/include/asm/entry-common.h @@ -29,6 +29,17 @@ static inline __must_check int arch_sysc } #define arch_syscall_enter_tracehook arch_syscall_enter_tracehook +static inline void arch_syscall_exit_tracehook(struct pt_regs *regs, bool step) +{ + int regno = (is_compat_task() ? 12 : 7); + unsigned long reg = regs->regs[regno]; + + regs->regs[regno] = PTRACE_SYSCALL_EXIT; + tracehook_report_syscall_exit(regs, step); + regs->regs[regno] = reg; +} +#define arch_syscall_exit_tracehook arch_syscall_exit_tracehook + static inline void arch_syscall_enter_audit(struct pt_regs *regs) { audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1], --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -13,13 +13,11 @@ #include <linux/kernel.h> #include <linux/sched/signal.h> #include <linux/sched/task_stack.h> -#include <linux/entry-common.h> #include <linux/mm.h> #include <linux/nospec.h> #include <linux/smp.h> #include <linux/ptrace.h> #include <linux/user.h> -#include <linux/seccomp.h> #include <linux/security.h> #include <linux/init.h> #include <linux/signal.h> @@ -28,7 +26,6 @@ #include <linux/perf_event.h> #include <linux/hw_breakpoint.h> #include <linux/regset.h> -#include <linux/tracehook.h> #include <linux/elf.h> #include <asm/compat.h> @@ -1779,41 +1776,6 @@ long arch_ptrace(struct task_struct *chi return ptrace_request(child, request, addr, data); } -static void tracehook_report_syscall(struct pt_regs *regs, - enum ptrace_syscall_dir dir) -{ - int regno; - unsigned long saved_reg; - - /* - * A scratch register (ip(r12) on AArch32, x7 on AArch64) is - * used to denote syscall entry/exit: - */ - regno = (is_compat_task() ? 12 : 7); - saved_reg = regs->regs[regno]; - regs->regs[regno] = dir; - - if (dir == PTRACE_SYSCALL_EXIT) - tracehook_report_syscall_exit(regs, 0); - else if (tracehook_report_syscall_entry(regs)) - forget_syscall(regs); - - regs->regs[regno] = saved_reg; -} - -void syscall_trace_exit(struct pt_regs *regs) -{ - audit_syscall_exit(regs); - - if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) - trace_sys_exit(regs, regs_return_value(regs)); - - if (test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT); - - rseq_syscall(regs); -} - /* * SPSR_ELx bits which are always architecturally RES0 per ARM DDI 0487D.a. * We permit userspace to set SSBS (AArch64 bit 12, AArch32 bit 23) which is --- a/arch/arm64/kernel/syscall.c +++ b/arch/arm64/kernel/syscall.c @@ -54,13 +54,6 @@ static void invoke_syscall(struct pt_reg regs->regs[0] = ret; } -static inline bool has_syscall_work(unsigned long flags) -{ - return unlikely(flags & _TIF_SYSCALL_WORK); -} - -void syscall_trace_exit(struct pt_regs *regs); - #ifdef CONFIG_ARM64_ERRATUM_1463225 DECLARE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa); @@ -106,12 +99,7 @@ static void el0_svc_common(struct pt_reg if (scno != NO_SYSCALL) invoke_syscall(regs, scno, sc_nr, syscall_table); - local_daif_mask(); - if (has_syscall_work(current_thread_info()->flags) || - IS_ENABLED(CONFIG_DEBUG_RSEQ)) { - local_daif_restore(DAIF_PROCCTX); - syscall_trace_exit(regs); - } + syscall_exit_to_usermode(regs, scno, regs_return_value(regs)); } static inline void sve_user_discard(void)
