projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 142781e1 TG |
1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | ||
| 3 | #include <linux/context_tracking.h> | |
| 4 | #include <linux/entry-common.h> | |
| 5 | ||
| 6 | #define CREATE_TRACE_POINTS | |
| 7 | #include <trace/events/syscalls.h> | |
| 8 | ||
| 9 | /** | |
| 10 | * enter_from_user_mode - Establish state when coming from user mode | |
| 11 | * | |
| 12 | * Syscall/interrupt entry disables interrupts, but user mode is traced as | |
| 13 | * interrupts enabled. Also with NO_HZ_FULL RCU might be idle. | |
| 14 | * | |
| 15 | * 1) Tell lockdep that interrupts are disabled | |
| 16 | * 2) Invoke context tracking if enabled to reactivate RCU | |
| 17 | * 3) Trace interrupts off state | |
| 18 | */ | |
| 19 | static __always_inline void enter_from_user_mode(struct pt_regs *regs) | |
| 20 | { | |
| 21 | arch_check_user_regs(regs); | |
| 22 | lockdep_hardirqs_off(CALLER_ADDR0); | |
| 23 | ||
| 24 | CT_WARN_ON(ct_state() != CONTEXT_USER); | |
| 25 | user_exit_irqoff(); | |
| 26 | ||
| 27 | instrumentation_begin(); | |
| 28 | trace_hardirqs_off_finish(); | |
| 29 | instrumentation_end(); | |
| 30 | } | |
| 31 | ||
| 32 | static inline void syscall_enter_audit(struct pt_regs *regs, long syscall) | |
| 33 | { | |
| 34 | if (unlikely(audit_context())) { | |
| 35 | unsigned long args[6]; | |
| 36 | ||
| 37 | syscall_get_arguments(current, regs, args); | |
| 38 | audit_syscall_entry(syscall, args[0], args[1], args[2], args[3]); | |
| 39 | } | |
| 40 | } | |
| 41 | ||
| 42 | static long syscall_trace_enter(struct pt_regs *regs, long syscall, | |
| 43 | unsigned long ti_work) | |
| 44 | { | |
| 45 | long ret = 0; | |
| 46 | ||
| 47 | /* Handle ptrace */ | |
| 48 | if (ti_work & (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU)) { | |
| 49 | ret = arch_syscall_enter_tracehook(regs); | |
| 50 | if (ret || (ti_work & _TIF_SYSCALL_EMU)) | |
| 51 | return -1L; | |
| 52 | } | |
| 53 | ||
| 54 | /* Do seccomp after ptrace, to catch any tracer changes. */ | |
| 55 | if (ti_work & _TIF_SECCOMP) { | |
| 56 | ret = __secure_computing(NULL); | |
| 57 | if (ret == -1L) | |
| 58 | return ret; | |
| 59 | } | |
| 60 | ||
| 61 | if (unlikely(ti_work & _TIF_SYSCALL_TRACEPOINT)) | |
| 62 | trace_sys_enter(regs, syscall); | |
| 63 | ||
| 64 | syscall_enter_audit(regs, syscall); | |
| 65 | ||
| 66 | return ret ? : syscall; | |
| 67 | } | |
| 68 | ||
| 69 | noinstr long syscall_enter_from_user_mode(struct pt_regs *regs, long syscall) | |
| 70 | { | |
| 71 | unsigned long ti_work; | |
| 72 | ||
| 73 | enter_from_user_mode(regs); | |
| 74 | instrumentation_begin(); | |
| 75 | ||
| 76 | local_irq_enable(); | |
| 77 | ti_work = READ_ONCE(current_thread_info()->flags); | |
| 78 | if (ti_work & SYSCALL_ENTER_WORK) | |
| 79 | syscall = syscall_trace_enter(regs, syscall, ti_work); | |
| 80 | instrumentation_end(); | |
| 81 | ||
| 82 | return syscall; | |
| 83 | } | |
| 84 | ||
| 85 | noinstr void irqentry_enter_from_user_mode(struct pt_regs *regs) | |
| 86 | { | |
| 87 | enter_from_user_mode(regs); | |
| 88 | } |