Author: Matthew Malcomson Date: 2021-01-13T11:35:09Z New Revision: 1854594b80b444dc21b830b51e53e05d38fc7d60
URL: https://github.com/llvm/llvm-project/commit/1854594b80b444dc21b830b51e53e05d38fc7d60 DIFF: https://github.com/llvm/llvm-project/commit/1854594b80b444dc21b830b51e53e05d38fc7d60.diff LOG: Hwasan InitPrctl check for error using internal_iserror When adding this function in https://reviews.llvm.org/D68794 I did not notice that internal_prctl has the API of the syscall to prctl rather than the API of the glibc (posix) wrapper. This means that the error return value is not necessarily -1 and that errno is not set by the call. For InitPrctl this means that the checks do not catch running on a kernel *without* the required ABI (not caught since I only tested this function correctly enables the ABI when it exists). This commit updates the two calls which check for an error condition to use `internal_iserror`. That function sets a provided integer to an equivalent errno value and returns a boolean to indicate success or not. Tested by running on a kernel that has this ABI and on one that does not. Verified that running on the kernel without this ABI the current code prints the provided error message and does not attempt to run the program. Verified that running on the kernel with this ABI the current code does not print an error message and turns on the ABI. All tests done on an AArch64 Linux machine. Reviewed By: eugenis Differential Revision: https://reviews.llvm.org/D94425 Added: Modified: compiler-rt/lib/hwasan/hwasan_linux.cpp Removed: ################################################################################ diff --git a/compiler-rt/lib/hwasan/hwasan_linux.cpp b/compiler-rt/lib/hwasan/hwasan_linux.cpp index e99926d355cf..793fd2fab6bf 100644 --- a/compiler-rt/lib/hwasan/hwasan_linux.cpp +++ b/compiler-rt/lib/hwasan/hwasan_linux.cpp @@ -119,8 +119,10 @@ void InitPrctl() { #define PR_GET_TAGGED_ADDR_CTRL 56 #define PR_TAGGED_ADDR_ENABLE (1UL << 0) // Check we're running on a kernel that can use the tagged address ABI. - if (internal_prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0) == (uptr)-1 && - errno == EINVAL) { + int local_errno = 0; + if (internal_iserror(internal_prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0), + &local_errno) && + local_errno == EINVAL) { #if SANITIZER_ANDROID // Some older Android kernels have the tagged pointer ABI on // unconditionally, and hence don't have the tagged-addr prctl while still @@ -137,8 +139,8 @@ void InitPrctl() { } // Turn on the tagged address ABI. - if (internal_prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE, 0, 0, 0) == - (uptr)-1 || + if (internal_iserror(internal_prctl(PR_SET_TAGGED_ADDR_CTRL, + PR_TAGGED_ADDR_ENABLE, 0, 0, 0)) || !internal_prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0)) { Printf( "FATAL: HWAddressSanitizer failed to enable tagged address syscall " _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
