[compiler-rt] Add aarch64 syscall optimization support

[zatrazz]

Summary

This patch adds the inline syscall support for aarch64 instead of relying
on the syscall runtime function. I had to use the macro system instead of
template one (as x86_64 does) because I have hit a issue with GCC where
named register through asm were not used in template instanciation
(and it has shown on both GCC 4.8 and GCC 4.9).

[samsonov]

lib/sanitizer_common/sanitizer_linux.cc

102

Please add this file to lib/sanitizer_common/CMakeLists.txt

lib/sanitizer_common/sanitizer_syscall_linux_aarch64.inc

29

Any specific reason for not using u64 for argument types as we do on x86_64?

[zatrazz]

Thanks for the review, I will repost the patch with the recommend changes.

lib/sanitizer_common/sanitizer_linux.cc

102

I will add it.

lib/sanitizer_common/sanitizer_syscall_linux_aarch64.inc

29

Not really, I will change it to u64.

[zatrazz]

Updated patch with recommended changes:

• Add sanitizer_syscall_linux_aarch64.inc to lib/sanitizer_common/CMakeLists.txt
• Use u64 on syscall wrappers

[rengolin]

How did you test this?

lib/sanitizer_common/sanitizer_syscall_linux_aarch64.inc

131

Some comments about this would be welcome.

[zatrazz]

The test is basically run the sanitizers tests and check for regression, since all internal syscalls will use the wrappers instead of normal syscall libc function.

lib/sanitizer_common/sanitizer_syscall_linux_aarch64.inc

131

This is the default return code Linux assumes for syscall failures (you can check on libc projects, like glibc and must, that they use the same return check value).

[rengolin]

lib/sanitizer_common/sanitizer_syscall_linux_aarch64.inc

131

I mean, on the code. :)

[rengolin]

Just add a brief description before internal_iserror() and LGTM. Thanks!

[samsonov]

LGTM

lib/sanitizer_common/CMakeLists.txt

107

Please sort the file names.

lib/sanitizer_common/CMakeLists.txt

set(SANITIZER_HEADERS
   sanitizer_stoptheworld.h
   sanitizer_suppressions.h
   sanitizer_symbolizer.h
   sanitizer_symbolizer_internal.h
   sanitizer_symbolizer_libbacktrace.h
   sanitizer_symbolizer_mac.h
   sanitizer_syscall_generic.inc
   sanitizer_syscall_linux_x86_64.inc
+  sanitizer_syscall_linux_aarch64.inc
   sanitizer_thread_registry.h)
 
 set(SANITIZER_COMMON_DEFINITIONS)
 
 if(MSVC)
   list(APPEND SANITIZER_COMMON_DEFINITIONS
     SANITIZER_NEEDS_SEGV=0)
 else()

lib/sanitizer_common/sanitizer_linux.cc

 #else
 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
 #endif
 
 namespace __sanitizer {
 
 #if SANITIZER_LINUX && defined(__x86_64__)
 #include "sanitizer_syscall_linux_x86_64.inc"
+#elif SANITIZER_LINUX && defined(__aarch64__)
+#include "sanitizer_syscall_linux_aarch64.inc"
 #else
 #include "sanitizer_syscall_generic.inc"
 #endif
 
 // --------------- sanitizer_libc.h
 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
                    OFF_T offset) {
 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS

lib/sanitizer_common/sanitizer_syscall_linux_aarch64.inc

+//===-- sanitizer_syscall_linux_aarch64.inc --------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Implementations of internal_syscall and internal_iserror for Linux/aarch64.
+//
+//===----------------------------------------------------------------------===//
+
+#define SYSCALL(name) __NR_ ## name
+
+static uptr __internal_syscall(u64 nr) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0");
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall0(n) \
+  (__internal_syscall)(n)
+
+static uptr __internal_syscall(u64 nr, u64 arg1) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall1(n, a1) \
+  (__internal_syscall)(n, (u64)(a1))
+
+static uptr __internal_syscall(u64 nr, u64 arg1, long arg2) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  register u64 x1 asm("x1") = arg2;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0), "r"(x1)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall2(n, a1, a2) \
+  (__internal_syscall)(n, (u64)(a1), (long)(a2))
+
+static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  register u64 x1 asm("x1") = arg2;
+  register u64 x2 asm("x2") = arg3;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0), "r"(x1), "r"(x2)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall3(n, a1, a2, a3) \
+  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3))
+
+static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3,
+                               u64 arg4) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  register u64 x1 asm("x1") = arg2;
+  register u64 x2 asm("x2") = arg3;
+  register u64 x3 asm("x3") = arg4;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0), "r"(x1), "r"(x2), "r"(x3)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall4(n, a1, a2, a3, a4) \
+  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3), (long)(a4))
+
+static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3,
+                               u64 arg4, long arg5) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  register u64 x1 asm("x1") = arg2;
+  register u64 x2 asm("x2") = arg3;
+  register u64 x3 asm("x3") = arg4;
+  register u64 x4 asm("x4") = arg5;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0), "r"(x1), "r"(x2), "r"(x3), "r"(x4)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall5(n, a1, a2, a3, a4, a5) \
+  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3), (long)(a4), \
+                       (u64)(a5))
+
+static uptr __internal_syscall(u64 nr, u64 arg1, long arg2, long arg3,
+                               u64 arg4, long arg5, long arg6) {
+  register u64 x8 asm("x8") = nr;
+  register u64 x0 asm("x0") = arg1;
+  register u64 x1 asm("x1") = arg2;
+  register u64 x2 asm("x2") = arg3;
+  register u64 x3 asm("x3") = arg4;
+  register u64 x4 asm("x4") = arg5;
+  register u64 x5 asm("x5") = arg6;
+  asm volatile("svc 0"
+               : "=r"(x0)
+               : "r"(x8), "0"(x0), "r"(x1), "r"(x2), "r"(x3), "r"(x4), "r"(x5)
+               : "memory", "cc");
+  return x0;
+}
+#define __internal_syscall6(n, a1, a2, a3, a4, a5, a6) \
+  (__internal_syscall)(n, (u64)(a1), (long)(a2), (long)(a3), (long)(a4), \
+                       (u64)(a5), (long)(a6))
+
+#define __SYSCALL_NARGS_X(a1, a2, a3, a4, a5, a6, a7, a8, n, ...) n
+#define __SYSCALL_NARGS(...) \
+  __SYSCALL_NARGS_X(__VA_ARGS__, 7, 6, 5, 4, 3, 2, 1, 0, )
+#define __SYSCALL_CONCAT_X(a, b) a##b
+#define __SYSCALL_CONCAT(a, b) __SYSCALL_CONCAT_X(a, b)
+#define __SYSCALL_DISP(b, ...) \
+  __SYSCALL_CONCAT(b, __SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)
+
+#define internal_syscall(...) __SYSCALL_DISP(__internal_syscall, __VA_ARGS__)
+
+
+bool internal_iserror(uptr retval, int *rverrno) {
+  if (retval >= (uptr)-4095) {
+    if (rverrno)
+      *rverrno = -retval;
+    return true;
+  }
+  return false;
+}