diff options
Diffstat (limited to 'absl/debugging/internal/address_is_readable.cc')
| -rw-r--r-- | absl/debugging/internal/address_is_readable.cc | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/absl/debugging/internal/address_is_readable.cc b/absl/debugging/internal/address_is_readable.cc index 91eaa76f..be17a105 100644 --- a/absl/debugging/internal/address_is_readable.cc +++ b/absl/debugging/internal/address_is_readable.cc @@ -50,8 +50,10 @@ namespace debugging_internal { // NOTE: any new system calls here may also require sandbox reconfiguration. // bool AddressIsReadable(const void *addr) { - // Align address on 8-byte boundary. On aarch64, checking last - // byte before inaccessible page returned unexpected EFAULT. + // rt_sigprocmask below checks 8 contiguous bytes. If addr resides in the + // last 7 bytes of a page (unaligned), rt_sigprocmask would additionally + // check the readability of the next page, which is not desired. Align + // address on 8-byte boundary to check only the current page. const uintptr_t u_addr = reinterpret_cast<uintptr_t>(addr) & ~uintptr_t{7}; addr = reinterpret_cast<const void *>(u_addr); |