diff options
author | Jack Lloyd <[email protected]> | 2019-01-05 10:46:42 -0500 |
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committer | Jack Lloyd <[email protected]> | 2019-01-05 10:50:16 -0500 |
commit | 23bd016eb9864c93fffbf87c97adf50444394bfb (patch) | |
tree | abfc5ca888080c83ff376cc6dddcec1fe6c7fbd1 | |
parent | 5930abcb9bebbb6ce03463d80a8551f048f7817a (diff) |
Revert #1798
The problem in #602 is not the use of mmap but the use of mmap with
MAP_SHARED. Using MAP_PRIVATE creates a CoW mapping just like malloc
or posix_memalign would.
I'm not sure why it took me so long to figure this out ...
-rw-r--r-- | src/lib/utils/os_utils.cpp | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/src/lib/utils/os_utils.cpp b/src/lib/utils/os_utils.cpp index 172fc27be..f373ece99 100644 --- a/src/lib/utils/os_utils.cpp +++ b/src/lib/utils/os_utils.cpp @@ -339,15 +339,25 @@ std::vector<void*> OS::allocate_locked_pages(size_t count) void* ptr = nullptr; #if defined(BOTAN_TARGET_OS_HAS_POSIX1) && defined(BOTAN_TARGET_OS_HAS_POSIX_MLOCK) - int rc = ::posix_memalign(&ptr, page_size, 2*page_size); - if(rc != 0 || ptr == nullptr) +#if !defined(MAP_NOCORE) + #define MAP_NOCORE 0 +#endif + + ptr = ::mmap(nullptr, 2*page_size, + PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE | MAP_NOCORE, + /*fd=*/-1, /*offset=*/0); + + if(ptr == MAP_FAILED) + { continue; + } // failed to lock if(::mlock(ptr, page_size) != 0) { - std::free(ptr); + ::munmap(ptr, 2*page_size); continue; } @@ -421,7 +431,7 @@ void OS::free_locked_pages(const std::vector<void*>& pages) #if defined(BOTAN_TARGET_OS_HAS_POSIX1) && defined(BOTAN_TARGET_OS_HAS_POSIX_MLOCK) ::munlock(ptr, page_size); - std::free(ptr); + ::munmap(ptr, 2*page_size); #elif defined(BOTAN_TARGET_OS_HAS_VIRTUAL_LOCK) ::VirtualUnlock(ptr, page_size); ::VirtualFree(ptr, 0, MEM_RELEASE); |