diff options
Diffstat (limited to 'third_party/abseil-cpp/absl/debugging/internal/vdso_support.cc')
-rw-r--r-- | third_party/abseil-cpp/absl/debugging/internal/vdso_support.cc | 45 |
1 files changed, 21 insertions, 24 deletions
diff --git a/third_party/abseil-cpp/absl/debugging/internal/vdso_support.cc b/third_party/abseil-cpp/absl/debugging/internal/vdso_support.cc index 1e8a78ac9c..977a9f6b3c 100644 --- a/third_party/abseil-cpp/absl/debugging/internal/vdso_support.cc +++ b/third_party/abseil-cpp/absl/debugging/internal/vdso_support.cc @@ -20,12 +20,25 @@ #ifdef ABSL_HAVE_VDSO_SUPPORT // defined in vdso_support.h +#if !defined(__has_include) +#define __has_include(header) 0 +#endif + #include <errno.h> #include <fcntl.h> +#if __has_include(<syscall.h>) +#include <syscall.h> +#elif __has_include(<sys/syscall.h>) #include <sys/syscall.h> +#endif #include <unistd.h> -#if __GLIBC_PREREQ(2, 16) // GLIBC-2.16 implements getauxval. +#if defined(__GLIBC__) && \ + (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 16)) +#define ABSL_HAVE_GETAUXVAL +#endif + +#ifdef ABSL_HAVE_GETAUXVAL #include <sys/auxv.h> #endif @@ -37,6 +50,11 @@ #define AT_SYSINFO_EHDR 33 // for crosstoolv10 #endif +#if defined(__FreeBSD__) +using Elf64_auxv_t = Elf64_Auxinfo; +using Elf32_auxv_t = Elf32_Auxinfo; +#endif + namespace absl { ABSL_NAMESPACE_BEGIN namespace debugging_internal { @@ -65,7 +83,7 @@ VDSOSupport::VDSOSupport() // the operation should be idempotent. const void *VDSOSupport::Init() { const auto kInvalidBase = debugging_internal::ElfMemImage::kInvalidBase; -#if __GLIBC_PREREQ(2, 16) +#ifdef ABSL_HAVE_GETAUXVAL if (vdso_base_.load(std::memory_order_relaxed) == kInvalidBase) { errno = 0; const void *const sysinfo_ehdr = @@ -74,17 +92,8 @@ const void *VDSOSupport::Init() { vdso_base_.store(sysinfo_ehdr, std::memory_order_relaxed); } } -#endif // __GLIBC_PREREQ(2, 16) +#endif // ABSL_HAVE_GETAUXVAL if (vdso_base_.load(std::memory_order_relaxed) == kInvalidBase) { - // Valgrind zaps AT_SYSINFO_EHDR and friends from the auxv[] - // on stack, and so glibc works as if VDSO was not present. - // But going directly to kernel via /proc/self/auxv below bypasses - // Valgrind zapping. So we check for Valgrind separately. - if (RunningOnValgrind()) { - vdso_base_.store(nullptr, std::memory_order_relaxed); - getcpu_fn_.store(&GetCPUViaSyscall, std::memory_order_relaxed); - return nullptr; - } int fd = open("/proc/self/auxv", O_RDONLY); if (fd == -1) { // Kernel too old to have a VDSO. @@ -175,18 +184,6 @@ int GetCPU() { return ret_code == 0 ? cpu : ret_code; } -// We need to make sure VDSOSupport::Init() is called before -// InitGoogle() does any setuid or chroot calls. If VDSOSupport -// is used in any global constructor, this will happen, since -// VDSOSupport's constructor calls Init. But if not, we need to -// ensure it here, with a global constructor of our own. This -// is an allowed exception to the normal rule against non-trivial -// global constructors. -static class VDSOInitHelper { - public: - VDSOInitHelper() { VDSOSupport::Init(); } -} vdso_init_helper; - } // namespace debugging_internal ABSL_NAMESPACE_END } // namespace absl |