sparc/compat: provide an accurate in_compat_syscall implementation
On sparc64 compat-enabled kernels, any task can make 32-bit and 64-bit
syscalls. is_compat_task returns true in 32-bit tasks, which does not
necessarily imply that the current syscall is 32-bit.
Provide an in_compat_syscall implementation that checks whether the
current syscall is compat.
As far as I know, sparc is the only architecture on which is_compat_task
checks the compat status of the task and on which the compat status of a
syscall can differ from the compat status of the task. On x86,
is_compat_task checks the syscall type, not the task type.
[akpm@linux-foundation.org: add comment, per Sam]
[akpm@linux-foundation.org: update comment, per Andy]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h
index 830502fe..6f251c4 100644
--- a/arch/sparc/include/asm/compat.h
+++ b/arch/sparc/include/asm/compat.h
@@ -307,4 +307,11 @@
return test_thread_flag(TIF_32BIT);
}
+static inline bool in_compat_syscall(void)
+{
+ /* Vector 0x110 is LINUX_32BIT_SYSCALL_TRAP */
+ return pt_regs_trap_type(current_pt_regs()) == 0x110;
+}
+#define in_compat_syscall in_compat_syscall
+
#endif /* _ASM_SPARC64_COMPAT_H */