x86 ptrace: unify syscall tracing
This unifies and cleans up the syscall tracing code on i386 and x86_64.
Using a single function for entry and exit tracing on 32-bit made the
do_syscall_trace() into some terrible spaghetti. The logic is clear and
simple using separate syscall_trace_enter() and syscall_trace_leave()
functions as on 64-bit.
The unification adds PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP support
on x86_64, for 32-bit ptrace() callers and for 64-bit ptrace() callers
tracing either 32-bit or 64-bit tasks. It behaves just like 32-bit.
Changing syscall_trace_enter() to return the syscall number shortens
all the assembly paths, while adding the SYSEMU feature in a simple way.
Signed-off-by: Roland McGrath <roland@redhat.com>
diff --git a/include/asm-x86/ptrace-abi.h b/include/asm-x86/ptrace-abi.h
index f224eb3..72e7b9d 100644
--- a/include/asm-x86/ptrace-abi.h
+++ b/include/asm-x86/ptrace-abi.h
@@ -73,11 +73,11 @@
#ifdef __x86_64__
# define PTRACE_ARCH_PRCTL 30
-#else
-# define PTRACE_SYSEMU 31
-# define PTRACE_SYSEMU_SINGLESTEP 32
#endif
+#define PTRACE_SYSEMU 31
+#define PTRACE_SYSEMU_SINGLESTEP 32
+
#define PTRACE_SINGLEBLOCK 33 /* resume execution until next branch */
#ifndef __ASSEMBLY__