| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _LINUX_PTRACE_H |
| #define _LINUX_PTRACE_H |
| |
| #include <linux/compiler.h> /* For unlikely. */ |
| #include <linux/sched.h> /* For struct task_struct. */ |
| #include <linux/sched/signal.h> /* For send_sig(), same_thread_group(), etc. */ |
| #include <linux/err.h> /* for IS_ERR_VALUE */ |
| #include <linux/bug.h> /* For BUG_ON. */ |
| #include <linux/pid_namespace.h> /* For task_active_pid_ns. */ |
| #include <uapi/linux/ptrace.h> |
| #include <linux/seccomp.h> |
| |
| /* Add sp to seccomp_data, as seccomp is user API, we don't want to modify it */ |
| struct syscall_info { |
| __u64 sp; |
| struct seccomp_data data; |
| }; |
| |
| extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, |
| void *buf, int len, unsigned int gup_flags); |
| |
| /* |
| * Ptrace flags |
| * |
| * The owner ship rules for task->ptrace which holds the ptrace |
| * flags is simple. When a task is running it owns it's task->ptrace |
| * flags. When the a task is stopped the ptracer owns task->ptrace. |
| */ |
| |
| #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ |
| #define PT_PTRACED 0x00000001 |
| #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ |
| |
| #define PT_OPT_FLAG_SHIFT 3 |
| /* PT_TRACE_* event enable flags */ |
| #define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event))) |
| #define PT_TRACESYSGOOD PT_EVENT_FLAG(0) |
| #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK) |
| #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK) |
| #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE) |
| #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC) |
| #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE) |
| #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT) |
| #define PT_TRACE_SECCOMP PT_EVENT_FLAG(PTRACE_EVENT_SECCOMP) |
| |
| #define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT) |
| #define PT_SUSPEND_SECCOMP (PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT) |
| |
| /* single stepping state bits (used on ARM and PA-RISC) */ |
| #define PT_SINGLESTEP_BIT 31 |
| #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) |
| #define PT_BLOCKSTEP_BIT 30 |
| #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) |
| |
| extern long arch_ptrace(struct task_struct *child, long request, |
| unsigned long addr, unsigned long data); |
| extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len); |
| extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len); |
| extern void ptrace_disable(struct task_struct *); |
| extern int ptrace_request(struct task_struct *child, long request, |
| unsigned long addr, unsigned long data); |
| extern void ptrace_notify(int exit_code); |
| extern void __ptrace_link(struct task_struct *child, |
| struct task_struct *new_parent, |
| const struct cred *ptracer_cred); |
| extern void __ptrace_unlink(struct task_struct *child); |
| extern void exit_ptrace(struct task_struct *tracer, struct list_head *dead); |
| #define PTRACE_MODE_READ 0x01 |
| #define PTRACE_MODE_ATTACH 0x02 |
| #define PTRACE_MODE_NOAUDIT 0x04 |
| #define PTRACE_MODE_FSCREDS 0x08 |
| #define PTRACE_MODE_REALCREDS 0x10 |
| |
| /* shorthands for READ/ATTACH and FSCREDS/REALCREDS combinations */ |
| #define PTRACE_MODE_READ_FSCREDS (PTRACE_MODE_READ | PTRACE_MODE_FSCREDS) |
| #define PTRACE_MODE_READ_REALCREDS (PTRACE_MODE_READ | PTRACE_MODE_REALCREDS) |
| #define PTRACE_MODE_ATTACH_FSCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_FSCREDS) |
| #define PTRACE_MODE_ATTACH_REALCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_REALCREDS) |
| |
| /** |
| * ptrace_may_access - check whether the caller is permitted to access |
| * a target task. |
| * @task: target task |
| * @mode: selects type of access and caller credentials |
| * |
| * Returns true on success, false on denial. |
| * |
| * One of the flags PTRACE_MODE_FSCREDS and PTRACE_MODE_REALCREDS must |
| * be set in @mode to specify whether the access was requested through |
| * a filesystem syscall (should use effective capabilities and fsuid |
| * of the caller) or through an explicit syscall such as |
| * process_vm_writev or ptrace (and should use the real credentials). |
| */ |
| extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); |
| |
| static inline int ptrace_reparented(struct task_struct *child) |
| { |
| return !same_thread_group(child->real_parent, child->parent); |
| } |
| |
| static inline void ptrace_unlink(struct task_struct *child) |
| { |
| if (unlikely(child->ptrace)) |
| __ptrace_unlink(child); |
| } |
| |
| int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
| unsigned long data); |
| int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, |
| unsigned long data); |
| |
| /** |
| * ptrace_parent - return the task that is tracing the given task |
| * @task: task to consider |
| * |
| * Returns %NULL if no one is tracing @task, or the &struct task_struct |
| * pointer to its tracer. |
| * |
| * Must called under rcu_read_lock(). The pointer returned might be kept |
| * live only by RCU. During exec, this may be called with task_lock() held |
| * on @task, still held from when check_unsafe_exec() was called. |
| */ |
| static inline struct task_struct *ptrace_parent(struct task_struct *task) |
| { |
| if (unlikely(task->ptrace)) |
| return rcu_dereference(task->parent); |
| return NULL; |
| } |
| |
| /** |
| * ptrace_event_enabled - test whether a ptrace event is enabled |
| * @task: ptracee of interest |
| * @event: %PTRACE_EVENT_* to test |
| * |
| * Test whether @event is enabled for ptracee @task. |
| * |
| * Returns %true if @event is enabled, %false otherwise. |
| */ |
| static inline bool ptrace_event_enabled(struct task_struct *task, int event) |
| { |
| return task->ptrace & PT_EVENT_FLAG(event); |
| } |
| |
| /** |
| * ptrace_event - possibly stop for a ptrace event notification |
| * @event: %PTRACE_EVENT_* value to report |
| * @message: value for %PTRACE_GETEVENTMSG to return |
| * |
| * Check whether @event is enabled and, if so, report @event and @message |
| * to the ptrace parent. |
| * |
| * Called without locks. |
| */ |
| static inline void ptrace_event(int event, unsigned long message) |
| { |
| if (unlikely(ptrace_event_enabled(current, event))) { |
| current->ptrace_message = message; |
| ptrace_notify((event << 8) | SIGTRAP); |
| } else if (event == PTRACE_EVENT_EXEC) { |
| /* legacy EXEC report via SIGTRAP */ |
| if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED) |
| send_sig(SIGTRAP, current, 0); |
| } |
| } |
| |
| /** |
| * ptrace_event_pid - possibly stop for a ptrace event notification |
| * @event: %PTRACE_EVENT_* value to report |
| * @pid: process identifier for %PTRACE_GETEVENTMSG to return |
| * |
| * Check whether @event is enabled and, if so, report @event and @pid |
| * to the ptrace parent. @pid is reported as the pid_t seen from the |
| * ptrace parent's pid namespace. |
| * |
| * Called without locks. |
| */ |
| static inline void ptrace_event_pid(int event, struct pid *pid) |
| { |
| /* |
| * FIXME: There's a potential race if a ptracer in a different pid |
| * namespace than parent attaches between computing message below and |
| * when we acquire tasklist_lock in ptrace_stop(). If this happens, |
| * the ptracer will get a bogus pid from PTRACE_GETEVENTMSG. |
| */ |
| unsigned long message = 0; |
| struct pid_namespace *ns; |
| |
| rcu_read_lock(); |
| ns = task_active_pid_ns(rcu_dereference(current->parent)); |
| if (ns) |
| message = pid_nr_ns(pid, ns); |
| rcu_read_unlock(); |
| |
| ptrace_event(event, message); |
| } |
| |
| /** |
| * ptrace_init_task - initialize ptrace state for a new child |
| * @child: new child task |
| * @ptrace: true if child should be ptrace'd by parent's tracer |
| * |
| * This is called immediately after adding @child to its parent's children |
| * list. @ptrace is false in the normal case, and true to ptrace @child. |
| * |
| * Called with current's siglock and write_lock_irq(&tasklist_lock) held. |
| */ |
| static inline void ptrace_init_task(struct task_struct *child, bool ptrace) |
| { |
| INIT_LIST_HEAD(&child->ptrace_entry); |
| INIT_LIST_HEAD(&child->ptraced); |
| child->jobctl = 0; |
| child->ptrace = 0; |
| child->parent = child->real_parent; |
| |
| if (unlikely(ptrace) && current->ptrace) { |
| child->ptrace = current->ptrace; |
| __ptrace_link(child, current->parent, current->ptracer_cred); |
| |
| if (child->ptrace & PT_SEIZED) |
| task_set_jobctl_pending(child, JOBCTL_TRAP_STOP); |
| else |
| sigaddset(&child->pending.signal, SIGSTOP); |
| } |
| else |
| child->ptracer_cred = NULL; |
| } |
| |
| /** |
| * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped |
| * @task: task in %EXIT_DEAD state |
| * |
| * Called with write_lock(&tasklist_lock) held. |
| */ |
| static inline void ptrace_release_task(struct task_struct *task) |
| { |
| BUG_ON(!list_empty(&task->ptraced)); |
| ptrace_unlink(task); |
| BUG_ON(!list_empty(&task->ptrace_entry)); |
| } |
| |
| #ifndef force_successful_syscall_return |
| /* |
| * System call handlers that, upon successful completion, need to return a |
| * negative value should call force_successful_syscall_return() right before |
| * returning. On architectures where the syscall convention provides for a |
| * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly |
| * others), this macro can be used to ensure that the error flag will not get |
| * set. On architectures which do not support a separate error flag, the macro |
| * is a no-op and the spurious error condition needs to be filtered out by some |
| * other means (e.g., in user-level, by passing an extra argument to the |
| * syscall handler, or something along those lines). |
| */ |
| #define force_successful_syscall_return() do { } while (0) |
| #endif |
| |
| #ifndef is_syscall_success |
| /* |
| * On most systems we can tell if a syscall is a success based on if the retval |
| * is an error value. On some systems like ia64 and powerpc they have different |
| * indicators of success/failure and must define their own. |
| */ |
| #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs)))) |
| #endif |
| |
| /* |
| * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. |
| * |
| * These do-nothing inlines are used when the arch does not |
| * implement single-step. The kerneldoc comments are here |
| * to document the interface for all arch definitions. |
| */ |
| |
| #ifndef arch_has_single_step |
| /** |
| * arch_has_single_step - does this CPU support user-mode single-step? |
| * |
| * If this is defined, then there must be function declarations or |
| * inlines for user_enable_single_step() and user_disable_single_step(). |
| * arch_has_single_step() should evaluate to nonzero iff the machine |
| * supports instruction single-step for user mode. |
| * It can be a constant or it can test a CPU feature bit. |
| */ |
| #define arch_has_single_step() (0) |
| |
| /** |
| * user_enable_single_step - single-step in user-mode task |
| * @task: either current or a task stopped in %TASK_TRACED |
| * |
| * This can only be called when arch_has_single_step() has returned nonzero. |
| * Set @task so that when it returns to user mode, it will trap after the |
| * next single instruction executes. If arch_has_block_step() is defined, |
| * this must clear the effects of user_enable_block_step() too. |
| */ |
| static inline void user_enable_single_step(struct task_struct *task) |
| { |
| BUG(); /* This can never be called. */ |
| } |
| |
| /** |
| * user_disable_single_step - cancel user-mode single-step |
| * @task: either current or a task stopped in %TASK_TRACED |
| * |
| * Clear @task of the effects of user_enable_single_step() and |
| * user_enable_block_step(). This can be called whether or not either |
| * of those was ever called on @task, and even if arch_has_single_step() |
| * returned zero. |
| */ |
| static inline void user_disable_single_step(struct task_struct *task) |
| { |
| } |
| #else |
| extern void user_enable_single_step(struct task_struct *); |
| extern void user_disable_single_step(struct task_struct *); |
| #endif /* arch_has_single_step */ |
| |
| #ifndef arch_has_block_step |
| /** |
| * arch_has_block_step - does this CPU support user-mode block-step? |
| * |
| * If this is defined, then there must be a function declaration or inline |
| * for user_enable_block_step(), and arch_has_single_step() must be defined |
| * too. arch_has_block_step() should evaluate to nonzero iff the machine |
| * supports step-until-branch for user mode. It can be a constant or it |
| * can test a CPU feature bit. |
| */ |
| #define arch_has_block_step() (0) |
| |
| /** |
| * user_enable_block_step - step until branch in user-mode task |
| * @task: either current or a task stopped in %TASK_TRACED |
| * |
| * This can only be called when arch_has_block_step() has returned nonzero, |
| * and will never be called when single-instruction stepping is being used. |
| * Set @task so that when it returns to user mode, it will trap after the |
| * next branch or trap taken. |
| */ |
| static inline void user_enable_block_step(struct task_struct *task) |
| { |
| BUG(); /* This can never be called. */ |
| } |
| #else |
| extern void user_enable_block_step(struct task_struct *); |
| #endif /* arch_has_block_step */ |
| |
| #ifdef ARCH_HAS_USER_SINGLE_STEP_REPORT |
| extern void user_single_step_report(struct pt_regs *regs); |
| #else |
| static inline void user_single_step_report(struct pt_regs *regs) |
| { |
| kernel_siginfo_t info; |
| clear_siginfo(&info); |
| info.si_signo = SIGTRAP; |
| info.si_errno = 0; |
| info.si_code = SI_USER; |
| info.si_pid = 0; |
| info.si_uid = 0; |
| force_sig_info(&info); |
| } |
| #endif |
| |
| #ifndef arch_ptrace_stop_needed |
| /** |
| * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called |
| * @code: current->exit_code value ptrace will stop with |
| * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with |
| * |
| * This is called with the siglock held, to decide whether or not it's |
| * necessary to release the siglock and call arch_ptrace_stop() with the |
| * same @code and @info arguments. It can be defined to a constant if |
| * arch_ptrace_stop() is never required, or always is. On machines where |
| * this makes sense, it should be defined to a quick test to optimize out |
| * calling arch_ptrace_stop() when it would be superfluous. For example, |
| * if the thread has not been back to user mode since the last stop, the |
| * thread state might indicate that nothing needs to be done. |
| * |
| * This is guaranteed to be invoked once before a task stops for ptrace and |
| * may include arch-specific operations necessary prior to a ptrace stop. |
| */ |
| #define arch_ptrace_stop_needed(code, info) (0) |
| #endif |
| |
| #ifndef arch_ptrace_stop |
| /** |
| * arch_ptrace_stop - Do machine-specific work before stopping for ptrace |
| * @code: current->exit_code value ptrace will stop with |
| * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with |
| * |
| * This is called with no locks held when arch_ptrace_stop_needed() has |
| * just returned nonzero. It is allowed to block, e.g. for user memory |
| * access. The arch can have machine-specific work to be done before |
| * ptrace stops. On ia64, register backing store gets written back to user |
| * memory here. Since this can be costly (requires dropping the siglock), |
| * we only do it when the arch requires it for this particular stop, as |
| * indicated by arch_ptrace_stop_needed(). |
| */ |
| #define arch_ptrace_stop(code, info) do { } while (0) |
| #endif |
| |
| #ifndef current_pt_regs |
| #define current_pt_regs() task_pt_regs(current) |
| #endif |
| |
| /* |
| * unlike current_pt_regs(), this one is equal to task_pt_regs(current) |
| * on *all* architectures; the only reason to have a per-arch definition |
| * is optimisation. |
| */ |
| #ifndef signal_pt_regs |
| #define signal_pt_regs() task_pt_regs(current) |
| #endif |
| |
| #ifndef current_user_stack_pointer |
| #define current_user_stack_pointer() user_stack_pointer(current_pt_regs()) |
| #endif |
| |
| extern int task_current_syscall(struct task_struct *target, struct syscall_info *info); |
| |
| extern void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact); |
| #endif |