syscall_get_arch: add "struct task_struct *" argument

This argument is required to extend the generic ptrace API with
PTRACE_GET_SYSCALL_INFO request: syscall_get_arch() is going
to be called from ptrace_request() along with syscall_get_nr(),
syscall_get_arguments(), syscall_get_error(), and
syscall_get_return_value() functions with a tracee as their argument.

The primary intent is that the triple (audit_arch, syscall_nr, arg1..arg6)
should describe what system call is being called and what its arguments
are.

Reverts: 5e937a9ae913 ("syscall_get_arch: remove useless function arguments")
Reverts: 1002d94d3076 ("syscall.h: fix doc text for syscall_get_arch()")
Reviewed-by: Andy Lutomirski <[email protected]> # for x86
Reviewed-by: Palmer Dabbelt <[email protected]>
Acked-by: Paul Moore <[email protected]>
Acked-by: Paul Burton <[email protected]> # MIPS parts
Acked-by: Michael Ellerman <[email protected]> (powerpc)
Acked-by: Kees Cook <[email protected]> # seccomp parts
Acked-by: Mark Salter <[email protected]> # for the c6x bit
Cc: Elvira Khabirova <[email protected]>
Cc: Eugene Syromyatnikov <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
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Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Dmitry V. Levin <[email protected]>
Signed-off-by: Paul Moore <[email protected]>

1 files changed, 3 insertions, 2 deletions

diff --git a/include/asm-generic/syscall.h b/include/asm-generic/syscall.h
index 0c938a4354f6..e0d060b43321 100644
--- a/include/asm-generic/syscall.h
+++ b/include/asm-generic/syscall.h
@@ -144,14 +144,15 @@ void syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
 
 /**
  * syscall_get_arch - return the AUDIT_ARCH for the current system call
+ * @task:	task of interest, must be blocked
  *
  * Returns the AUDIT_ARCH_* based on the system call convention in use.
  *
- * It's only valid to call this when current is stopped on entry to a system
+ * It's only valid to call this when @task is stopped on entry to a system
  * call, due to %TIF_SYSCALL_TRACE, %TIF_SYSCALL_AUDIT, or %TIF_SECCOMP.
  *
  * Architectures which permit CONFIG_HAVE_ARCH_SECCOMP_FILTER must
  * provide an implementation of this.
  */
-int syscall_get_arch(void);
+int syscall_get_arch(struct task_struct *task);
 #endif	/* _ASM_SYSCALL_H */