Merge pull request #1 from google/master

catch up

4 files changed, 43 insertions, 48 deletions

diff --git a/vdso/BUILD b/vdso/BUILD
index 7ceed349e..d37d4266d 100644
--- a/vdso/BUILD
+++ b/vdso/BUILD
@@ -3,20 +3,10 @@
 #   normal system VDSO (time, gettimeofday, clock_gettimeofday) but which uses
 #   timekeeping parameters managed by the sandbox kernel.
 
-load("@bazel_tools//tools/cpp:cc_flags_supplier.bzl", "cc_flags_supplier")
+load("//tools:defs.bzl", "cc_flags_supplier", "cc_toolchain", "select_arch")
 
 package(licenses = ["notice"])
 
-config_setting(
-    name = "x86_64",
-    constraint_values = ["@bazel_tools//platforms:x86_64"],
-)
-
-config_setting(
-    name = "aarch64",
-    constraint_values = ["@bazel_tools//platforms:aarch64"],
-)
-
 genrule(
     name = "vdso",
     srcs = [
@@ -39,14 +29,15 @@ genrule(
           "-O2 " +
           "-std=c++11 " +
           "-fPIC " +
+          "-fno-sanitize=all " +
           # Some toolchains enable stack protector by default. Disable it, the
           # VDSO has no hooks to handle failures.
           "-fno-stack-protector " +
           "-fuse-ld=gold " +
-          select({
-              ":x86_64": "-m64 ",
-              "//conditions:default": "",
-          }) +
+          select_arch(
+              amd64 = "-m64 ",
+              arm64 = "",
+          ) +
           "-shared " +
           "-nostdlib " +
           "-Wl,-soname=linux-vdso.so.1 " +
@@ -55,12 +46,10 @@ genrule(
           "-Wl,-Bsymbolic " +
           "-Wl,-z,max-page-size=4096 " +
           "-Wl,-z,common-page-size=4096 " +
-          select(
-              {
-                  ":x86_64": "-Wl,-T$(location vdso_amd64.lds) ",
-                  ":aarch64": "-Wl,-T$(location vdso_arm64.lds) ",
-              },
-              no_match_error = "Unsupported architecture",
+          select_arch(
+              amd64 = "-Wl,-T$(location vdso_amd64.lds) ",
+              arm64 = "-Wl,-T$(location vdso_arm64.lds) ",
+              no_match_error = "unsupported architecture",
           ) +
           "-o $(location vdso.so) " +
           "$(location vdso.cc) " +
@@ -68,14 +57,14 @@ genrule(
           "&& $(location :check_vdso) " +
           "--check-data " +
           "--vdso $(location vdso.so) ",
+    exec_tools = [
+        ":check_vdso",
+    ],
     features = ["-pie"],
     toolchains = [
-        "@bazel_tools//tools/cpp:current_cc_toolchain",
+        cc_toolchain,
         ":no_pie_cc_flags",
     ],
-    tools = [
-        ":check_vdso",
-    ],
     visibility = ["//:sandbox"],
 )
 
@@ -87,6 +76,6 @@ cc_flags_supplier(
 py_binary(
     name = "check_vdso",
     srcs = ["check_vdso.py"],
-    python_version = "PY2",
+    python_version = "PY3",
     visibility = ["//:sandbox"],
 )
diff --git a/vdso/syscalls.h b/vdso/syscalls.h
index f5865bb72..0c6a922a0 100644
--- a/vdso/syscalls.h
+++ b/vdso/syscalls.h
@@ -26,6 +26,9 @@
 #include <stddef.h>
 #include <sys/types.h>
 
+#define __stringify_1(x...) #x
+#define __stringify(x...) __stringify_1(x)
+
 namespace vdso {
 
 #if __x86_64__
@@ -51,22 +54,15 @@ static inline int sys_getcpu(unsigned* cpu, unsigned* node,
   return num;
 }
 
-#elif __aarch64__
-
-static inline int sys_rt_sigreturn(void) {
-  int num = __NR_rt_sigreturn;
-
-  asm volatile(
-      "mov x8, %0\n"
-      "svc #0    \n"
-      : "+r"(num)
-      :
-      :);
-  return num;
+static inline void sys_rt_sigreturn(void) {
+  asm volatile("movl $" __stringify(__NR_rt_sigreturn)", %eax \n"
+               "syscall \n");
 }
 
-static inline int sys_clock_gettime(clockid_t _clkid, struct timespec *_ts) {
-  register struct timespec *ts asm("x1") = _ts;
+#elif __aarch64__
+
+static inline int sys_clock_gettime(clockid_t _clkid, struct timespec* _ts) {
+  register struct timespec* ts asm("x1") = _ts;
   register clockid_t clkid asm("x0") = _clkid;
   register long ret asm("x0");
   register long nr asm("x8") = __NR_clock_gettime;
@@ -78,8 +74,8 @@ static inline int sys_clock_gettime(clockid_t _clkid, struct timespec *_ts) {
   return ret;
 }
 
-static inline int sys_clock_getres(clockid_t _clkid, struct timespec *_ts) {
-  register struct timespec *ts asm("x1") = _ts;
+static inline int sys_clock_getres(clockid_t _clkid, struct timespec* _ts) {
+  register struct timespec* ts asm("x1") = _ts;
   register clockid_t clkid asm("x0") = _clkid;
   register long ret asm("x0");
   register long nr asm("x8") = __NR_clock_getres;
@@ -91,6 +87,11 @@ static inline int sys_clock_getres(clockid_t _clkid, struct timespec *_ts) {
   return ret;
 }
 
+static inline void sys_rt_sigreturn(void) {
+  asm volatile("mov x8, #" __stringify(__NR_rt_sigreturn)" \n"
+               "svc #0 \n");
+}
+
 #else
 #error "unsupported architecture"
 #endif
diff --git a/vdso/vdso.cc b/vdso/vdso.cc
index 8bb80a7a4..3b6653b5d 100644
--- a/vdso/vdso.cc
+++ b/vdso/vdso.cc
@@ -69,6 +69,12 @@ int __common_gettimeofday(struct timeval* tv, struct timezone* tz) {
 }
 }  // namespace
 
+// __kernel_rt_sigreturn() implements rt_sigreturn()
+extern "C" void __kernel_rt_sigreturn(unsigned long unused) {
+  // No optimizations yet, just make the real system call.
+  sys_rt_sigreturn();
+}
+
 #if __x86_64__
 
 // __vdso_clock_gettime() implements clock_gettime()
@@ -126,6 +132,10 @@ extern "C" int __kernel_clock_getres(clockid_t clock, struct timespec* res) {
     case CLOCK_REALTIME:
     case CLOCK_MONOTONIC:
     case CLOCK_BOOTTIME: {
+      if (res == nullptr) {
+        return 0;
+      }
+
       res->tv_sec = 0;
       res->tv_nsec = 1;
       break;
@@ -139,12 +149,6 @@ extern "C" int __kernel_clock_getres(clockid_t clock, struct timespec* res) {
   return ret;
 }
 
-// __kernel_rt_sigreturn() implements gettimeofday()
-extern "C" int __kernel_rt_sigreturn(unsigned long unused) {
-  // No optimizations yet, just make the real system call.
-  return sys_rt_sigreturn();
-}
-
 #else
 #error "unsupported architecture"
 #endif
diff --git a/vdso/vdso_amd64.lds b/vdso/vdso_amd64.lds
index e2615ae9e..d114290da 100644
--- a/vdso/vdso_amd64.lds
+++ b/vdso/vdso_amd64.lds
@@ -95,6 +95,7 @@ VERSION {
     __vdso_getcpu;
     time;
     __vdso_time;
+    __kernel_rt_sigreturn;
 
   local: *;
   };