include/asm-generic/syscall.h

Source file repositories/reference/linux-study-clean/include/asm-generic/syscall.h

File Facts

System
Linux kernel
Corpus path
include/asm-generic/syscall.h
Extension
.h
Size
6233 bytes
Lines
165
Domain
Repository Root And Misc
Bucket
include
Inferred role
Repository Root And Misc: syscall or user/kernel boundary
Status
core implementation candidate

Why This File Exists

Top-level or miscellaneous repository surface. Use this as map coverage unless a later manual pass promotes the file into a deeper subsystem dossier.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _ASM_SYSCALL_H
#define _ASM_SYSCALL_H	1

struct task_struct;
struct pt_regs;

/**
 * syscall_get_nr - find what system call a task is executing
 * @task:	task of interest, must be blocked
 * @regs:	task_pt_regs() of @task
 *
 * If @task is executing a system call or is at system call
 * tracing about to attempt one, returns the system call number.
 * If @task is not executing a system call, i.e. it's blocked
 * inside the kernel for a fault or signal, returns -1.
 *
 * Note this returns int even on 64-bit machines.  Only 32 bits of
 * system call number can be meaningful.  If the actual arch value
 * is 64 bits, this truncates to 32 bits so 0xffffffff means -1.
 *
 * It's only valid to call this when @task is known to be blocked.
 */
int syscall_get_nr(struct task_struct *task, struct pt_regs *regs);

/**
 * syscall_set_nr - change the system call a task is executing
 * @task:	task of interest, must be blocked
 * @regs:	task_pt_regs() of @task
 * @nr:		system call number
 *
 * Changes the system call number @task is about to execute.
 *
 * It's only valid to call this when @task is stopped for tracing on
 * entry to a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or
 * %SYSCALL_WORK_SYSCALL_AUDIT.
 */
void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr);

/**
 * syscall_rollback - roll back registers after an aborted system call
 * @task:	task of interest, must be in system call exit tracing
 * @regs:	task_pt_regs() of @task
 *
 * It's only valid to call this when @task is stopped for system
 * call exit tracing (due to %SYSCALL_WORK_SYSCALL_TRACE or
 * %SYSCALL_WORK_SYSCALL_AUDIT), after ptrace_report_syscall_entry()
 * returned nonzero to prevent the system call from taking place.
 *
 * This rolls back the register state in @regs so it's as if the
 * system call instruction was a no-op.  The registers containing
 * the system call number and arguments are as they were before the
 * system call instruction.  This may not be the same as what the
 * register state looked like at system call entry tracing.
 */
void syscall_rollback(struct task_struct *task, struct pt_regs *regs);

/**
 * syscall_get_error - check result of traced system call
 * @task:	task of interest, must be blocked
 * @regs:	task_pt_regs() of @task
 *
 * Returns 0 if the system call succeeded, or -ERRORCODE if it failed.
 *
 * It's only valid to call this when @task is stopped for tracing on exit
 * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or
 * %SYSCALL_WORK_SYSCALL_AUDIT.
 */
long syscall_get_error(struct task_struct *task, struct pt_regs *regs);

/**
 * syscall_get_return_value - get the return value of a traced system call
 * @task:	task of interest, must be blocked
 * @regs:	task_pt_regs() of @task
 *
 * Returns the return value of the successful system call.
 * This value is meaningless if syscall_get_error() returned nonzero.
 *
 * It's only valid to call this when @task is stopped for tracing on exit
 * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or
 * %SYSCALL_WORK_SYSCALL_AUDIT.
 */
long syscall_get_return_value(struct task_struct *task, struct pt_regs *regs);

/**
 * syscall_set_return_value - change the return value of a traced system call
 * @task:	task of interest, must be blocked
 * @regs:	task_pt_regs() of @task
 * @error:	negative error code, or zero to indicate success
 * @val:	user return value if @error is zero
 *

Annotation

Implementation Notes