Merge branch 'core/entry' into sched/core
Pull the entry update to avoid merge conflicts with the time slice extension changes. Signed-off-by: Thomas Gleixner <tglx@kernel.org>
This commit is contained in:
Thomas Gleixner
commit
5c4378b7b0
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@ -2,6 +2,7 @@
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#ifndef __LINUX_ENTRYCOMMON_H
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#define __LINUX_ENTRYCOMMON_H
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#include <linux/audit.h>
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#include <linux/irq-entry-common.h>
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#include <linux/livepatch.h>
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#include <linux/ptrace.h>
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@ -45,7 +46,84 @@
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SYSCALL_WORK_SYSCALL_EXIT_TRAP | \
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ARCH_SYSCALL_WORK_EXIT)
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long syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long work);
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/**
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* arch_ptrace_report_syscall_entry - Architecture specific ptrace_report_syscall_entry() wrapper
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*
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* Invoked from syscall_trace_enter() to wrap ptrace_report_syscall_entry().
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*
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* This allows architecture specific ptrace_report_syscall_entry()
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* implementations. If not defined by the architecture this falls back to
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* to ptrace_report_syscall_entry().
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*/
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static __always_inline int arch_ptrace_report_syscall_entry(struct pt_regs *regs);
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#ifndef arch_ptrace_report_syscall_entry
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static __always_inline int arch_ptrace_report_syscall_entry(struct pt_regs *regs)
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{
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return ptrace_report_syscall_entry(regs);
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}
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#endif
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bool syscall_user_dispatch(struct pt_regs *regs);
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long trace_syscall_enter(struct pt_regs *regs, long syscall);
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void trace_syscall_exit(struct pt_regs *regs, long ret);
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static inline void syscall_enter_audit(struct pt_regs *regs, long syscall)
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{
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if (unlikely(audit_context())) {
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unsigned long args[6];
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syscall_get_arguments(current, regs, args);
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audit_syscall_entry(syscall, args[0], args[1], args[2], args[3]);
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}
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}
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static __always_inline long syscall_trace_enter(struct pt_regs *regs, unsigned long work)
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{
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long syscall, ret = 0;
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/*
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* Handle Syscall User Dispatch. This must comes first, since
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* the ABI here can be something that doesn't make sense for
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* other syscall_work features.
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*/
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if (work & SYSCALL_WORK_SYSCALL_USER_DISPATCH) {
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if (syscall_user_dispatch(regs))
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return -1L;
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}
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/*
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* User space got a time slice extension granted and relinquishes
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* the CPU. The work stops the slice timer to avoid an extra round
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* through hrtimer_interrupt().
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*/
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if (work & SYSCALL_WORK_SYSCALL_RSEQ_SLICE)
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rseq_syscall_enter_work(syscall_get_nr(current, regs));
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/* Handle ptrace */
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if (work & (SYSCALL_WORK_SYSCALL_TRACE | SYSCALL_WORK_SYSCALL_EMU)) {
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ret = arch_ptrace_report_syscall_entry(regs);
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if (ret || (work & SYSCALL_WORK_SYSCALL_EMU))
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return -1L;
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}
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/* Do seccomp after ptrace, to catch any tracer changes. */
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if (work & SYSCALL_WORK_SECCOMP) {
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ret = __secure_computing();
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if (ret == -1L)
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return ret;
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}
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/* Either of the above might have changed the syscall number */
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syscall = syscall_get_nr(current, regs);
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if (unlikely(work & SYSCALL_WORK_SYSCALL_TRACEPOINT))
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syscall = trace_syscall_enter(regs, syscall);
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syscall_enter_audit(regs, syscall);
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return ret ? : syscall;
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}
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/**
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* syscall_enter_from_user_mode_work - Check and handle work before invoking
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@ -75,7 +153,7 @@ static __always_inline long syscall_enter_from_user_mode_work(struct pt_regs *re
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unsigned long work = READ_ONCE(current_thread_info()->syscall_work);
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if (work & SYSCALL_WORK_ENTER)
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syscall = syscall_trace_enter(regs, syscall, work);
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syscall = syscall_trace_enter(regs, work);
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return syscall;
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}
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@ -112,6 +190,37 @@ static __always_inline long syscall_enter_from_user_mode(struct pt_regs *regs, l
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return ret;
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}
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/*
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* If SYSCALL_EMU is set, then the only reason to report is when
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* SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall
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* instruction has been already reported in syscall_enter_from_user_mode().
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*/
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static __always_inline bool report_single_step(unsigned long work)
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{
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if (work & SYSCALL_WORK_SYSCALL_EMU)
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return false;
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return work & SYSCALL_WORK_SYSCALL_EXIT_TRAP;
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}
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/**
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* arch_ptrace_report_syscall_exit - Architecture specific ptrace_report_syscall_exit()
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*
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* This allows architecture specific ptrace_report_syscall_exit()
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* implementations. If not defined by the architecture this falls back to
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* to ptrace_report_syscall_exit().
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*/
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static __always_inline void arch_ptrace_report_syscall_exit(struct pt_regs *regs,
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int step);
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#ifndef arch_ptrace_report_syscall_exit
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static __always_inline void arch_ptrace_report_syscall_exit(struct pt_regs *regs,
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int step)
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{
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ptrace_report_syscall_exit(regs, step);
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}
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#endif
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/**
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* syscall_exit_work - Handle work before returning to user mode
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* @regs: Pointer to current pt_regs
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@ -119,20 +228,40 @@ static __always_inline long syscall_enter_from_user_mode(struct pt_regs *regs, l
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*
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* Do one-time syscall specific work.
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*/
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void syscall_exit_work(struct pt_regs *regs, unsigned long work);
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static __always_inline void syscall_exit_work(struct pt_regs *regs, unsigned long work)
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{
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bool step;
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/*
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* If the syscall was rolled back due to syscall user dispatching,
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* then the tracers below are not invoked for the same reason as
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* the entry side was not invoked in syscall_trace_enter(): The ABI
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* of these syscalls is unknown.
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*/
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if (work & SYSCALL_WORK_SYSCALL_USER_DISPATCH) {
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if (unlikely(current->syscall_dispatch.on_dispatch)) {
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current->syscall_dispatch.on_dispatch = false;
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return;
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}
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}
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audit_syscall_exit(regs);
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if (work & SYSCALL_WORK_SYSCALL_TRACEPOINT)
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trace_syscall_exit(regs, syscall_get_return_value(current, regs));
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step = report_single_step(work);
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if (step || work & SYSCALL_WORK_SYSCALL_TRACE)
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arch_ptrace_report_syscall_exit(regs, step);
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}
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/**
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* syscall_exit_to_user_mode_work - Handle work before returning to user mode
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* syscall_exit_to_user_mode_work - Handle one time work before returning to user mode
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* @regs: Pointer to currents pt_regs
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*
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* Same as step 1 and 2 of syscall_exit_to_user_mode() but without calling
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* exit_to_user_mode() to perform the final transition to user mode.
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* Step 1 of syscall_exit_to_user_mode() with the same calling convention.
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*
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* Calling convention is the same as for syscall_exit_to_user_mode() and it
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* returns with all work handled and interrupts disabled. The caller must
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* invoke exit_to_user_mode() before actually switching to user mode to
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* make the final state transitions. Interrupts must stay disabled between
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* return from this function and the invocation of exit_to_user_mode().
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* The caller must invoke steps 2-3 of syscall_exit_to_user_mode() afterwards.
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*/
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static __always_inline void syscall_exit_to_user_mode_work(struct pt_regs *regs)
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{
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@ -155,15 +284,13 @@ static __always_inline void syscall_exit_to_user_mode_work(struct pt_regs *regs)
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*/
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if (unlikely(work & SYSCALL_WORK_EXIT))
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syscall_exit_work(regs, work);
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local_irq_disable_exit_to_user();
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syscall_exit_to_user_mode_prepare(regs);
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}
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/**
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* syscall_exit_to_user_mode - Handle work before returning to user mode
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* @regs: Pointer to currents pt_regs
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*
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* Invoked with interrupts enabled and fully valid regs. Returns with all
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* Invoked with interrupts enabled and fully valid @regs. Returns with all
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* work handled, interrupts disabled such that the caller can immediately
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* switch to user mode. Called from architecture specific syscall and ret
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* from fork code.
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* - ptrace (single stepping)
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*
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* 2) Preparatory work
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* - Disable interrupts
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* - Exit to user mode loop (common TIF handling). Invokes
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* arch_exit_to_user_mode_work() for architecture specific TIF work
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* - Architecture specific one time work arch_exit_to_user_mode_prepare()
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@ -184,14 +312,17 @@ static __always_inline void syscall_exit_to_user_mode_work(struct pt_regs *regs)
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* 3) Final transition (lockdep, tracing, context tracking, RCU), i.e. the
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* functionality in exit_to_user_mode().
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*
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* This is a combination of syscall_exit_to_user_mode_work() (1,2) and
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* exit_to_user_mode(). This function is preferred unless there is a
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* compelling architectural reason to use the separate functions.
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* This is a combination of syscall_exit_to_user_mode_work() (1), disabling
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* interrupts followed by syscall_exit_to_user_mode_prepare() (2) and
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* exit_to_user_mode() (3). This function is preferred unless there is a
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* compelling architectural reason to invoke the functions separately.
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*/
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static __always_inline void syscall_exit_to_user_mode(struct pt_regs *regs)
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{
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instrumentation_begin();
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syscall_exit_to_user_mode_work(regs);
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local_irq_disable_exit_to_user();
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syscall_exit_to_user_mode_prepare(regs);
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instrumentation_end();
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exit_to_user_mode();
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}
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@ -1,7 +0,0 @@
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _COMMON_H
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#define _COMMON_H
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bool syscall_user_dispatch(struct pt_regs *regs);
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#endif
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@ -1,111 +1,23 @@
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// SPDX-License-Identifier: GPL-2.0
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#include <linux/audit.h>
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#include <linux/entry-common.h>
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#include "common.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/syscalls.h>
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static inline void syscall_enter_audit(struct pt_regs *regs, long syscall)
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/* Out of line to prevent tracepoint code duplication */
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long trace_syscall_enter(struct pt_regs *regs, long syscall)
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{
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if (unlikely(audit_context())) {
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unsigned long args[6];
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syscall_get_arguments(current, regs, args);
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audit_syscall_entry(syscall, args[0], args[1], args[2], args[3]);
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}
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}
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long syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long work)
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{
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long ret = 0;
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/*
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* Handle Syscall User Dispatch. This must comes first, since
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* the ABI here can be something that doesn't make sense for
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* other syscall_work features.
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*/
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if (work & SYSCALL_WORK_SYSCALL_USER_DISPATCH) {
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if (syscall_user_dispatch(regs))
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return -1L;
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}
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/*
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* User space got a time slice extension granted and relinquishes
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* the CPU. The work stops the slice timer to avoid an extra round
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* through hrtimer_interrupt().
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*/
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if (work & SYSCALL_WORK_SYSCALL_RSEQ_SLICE)
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rseq_syscall_enter_work(syscall);
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/* Handle ptrace */
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if (work & (SYSCALL_WORK_SYSCALL_TRACE | SYSCALL_WORK_SYSCALL_EMU)) {
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ret = ptrace_report_syscall_entry(regs);
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if (ret || (work & SYSCALL_WORK_SYSCALL_EMU))
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return -1L;
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}
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/* Do seccomp after ptrace, to catch any tracer changes. */
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if (work & SYSCALL_WORK_SECCOMP) {
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ret = __secure_computing();
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if (ret == -1L)
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return ret;
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}
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/* Either of the above might have changed the syscall number */
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syscall = syscall_get_nr(current, regs);
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if (unlikely(work & SYSCALL_WORK_SYSCALL_TRACEPOINT)) {
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trace_sys_enter(regs, syscall);
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/*
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* Probes or BPF hooks in the tracepoint may have changed the
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* system call number as well.
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* system call number. Reread it.
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*/
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syscall = syscall_get_nr(current, regs);
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}
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syscall_enter_audit(regs, syscall);
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return ret ? : syscall;
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return syscall_get_nr(current, regs);
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}
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/*
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* If SYSCALL_EMU is set, then the only reason to report is when
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* SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall
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* instruction has been already reported in syscall_enter_from_user_mode().
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*/
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static inline bool report_single_step(unsigned long work)
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void trace_syscall_exit(struct pt_regs *regs, long ret)
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{
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if (work & SYSCALL_WORK_SYSCALL_EMU)
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return false;
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return work & SYSCALL_WORK_SYSCALL_EXIT_TRAP;
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}
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void syscall_exit_work(struct pt_regs *regs, unsigned long work)
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{
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bool step;
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/*
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* If the syscall was rolled back due to syscall user dispatching,
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* then the tracers below are not invoked for the same reason as
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* the entry side was not invoked in syscall_trace_enter(): The ABI
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* of these syscalls is unknown.
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*/
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if (work & SYSCALL_WORK_SYSCALL_USER_DISPATCH) {
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if (unlikely(current->syscall_dispatch.on_dispatch)) {
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current->syscall_dispatch.on_dispatch = false;
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return;
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}
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}
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audit_syscall_exit(regs);
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if (work & SYSCALL_WORK_SYSCALL_TRACEPOINT)
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trace_sys_exit(regs, syscall_get_return_value(current, regs));
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step = report_single_step(work);
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if (step || work & SYSCALL_WORK_SYSCALL_TRACE)
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ptrace_report_syscall_exit(regs, step);
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trace_sys_exit(regs, ret);
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}
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@ -2,6 +2,8 @@
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/*
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* Copyright (C) 2020 Collabora Ltd.
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*/
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#include <linux/entry-common.h>
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#include <linux/sched.h>
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#include <linux/prctl.h>
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#include <linux/ptrace.h>
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@ -15,8 +17,6 @@
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#include <asm/syscall.h>
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#include "common.h"
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static void trigger_sigsys(struct pt_regs *regs)
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{
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struct kernel_siginfo info;
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Reference in New Issue