diff options
Diffstat (limited to 'src/libstd/sys')
| -rw-r--r-- | src/libstd/sys/unix/thread.rs | 29 |
1 files changed, 13 insertions, 16 deletions
diff --git a/src/libstd/sys/unix/thread.rs b/src/libstd/sys/unix/thread.rs index f32016ce1d6..7fdecc9c0c0 100644 --- a/src/libstd/sys/unix/thread.rs +++ b/src/libstd/sys/unix/thread.rs @@ -326,23 +326,20 @@ pub mod guard { // Reallocate the last page of the stack. // This ensures SIGBUS will be raised on // stack overflow. - if cfg!(target_os = "netbsd") { - let result = mmap(stackaddr, PAGE_SIZE, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0); - if result != stackaddr || result == MAP_FAILED { - panic!("failed to allocate a guard page"); - } - let result = mprotect(stackaddr, PAGE_SIZE, 0); + // Systems which enforce strict PAX MPROTECT do not allow + // to mprotect() a mapping with less restrictive permissions + // than the initial mmap() used, so we mmap() here with + // read/write permissions and only then mprotect() it to + // no permissions at all. See issue #50313. + let result = mmap(stackaddr, PAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0); + if result != stackaddr || result == MAP_FAILED { + panic!("failed to allocate a guard page"); + } - if result != 0 { - panic!("unable to protect the guard page"); - } - } else { - let result = mmap(stackaddr, PAGE_SIZE, PROT_NONE, - MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0); - if result != stackaddr || result == MAP_FAILED { - panic!("failed to allocate a guard page"); - } + let result = mprotect(stackaddr, PAGE_SIZE, PROT_NONE); + if result != 0 { + panic!("failed to protect the guard page"); } let guardaddr = stackaddr as usize; |