diff options
| author | Ben Gamari <ben@smart-cactus.org> | 2020-11-18 11:40:29 -0500 |
|---|---|---|
| committer | GHC GitLab CI <ghc-ci@gitlab-haskell.org> | 2020-12-07 15:14:40 +0000 |
| commit | 658b7fc9bf450b531655745f582ff0d0e369fe33 (patch) | |
| tree | 57cf9ad6a67c6427f14948719c33a395cf8e3ae4 | |
| parent | 4f01c8b4ef2a1ac81f3ea242ef6b41e3f6582f23 (diff) | |
| download | haskell-658b7fc9bf450b531655745f582ff0d0e369fe33.tar.gz | |
rts/linker: Align bssSize to page size when mapping symbol extras
We place symbol_extras right after bss. We also need
to ensure that symbol_extras can be mprotect'd independently from the
rest of the image. To ensure this we round up the size of bss to a page
boundary, thus ensuring that symbol_extras is also page-aligned.
(cherry picked from commit 9f40cf6ca9fb24dbc55f7eae43e2b89aa12bf251)
(cherry picked from commit 4b83b6a8f8ac08e81b6e75c47f133e3ed6bdea95)
| -rw-r--r-- | rts/linker/SymbolExtras.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/rts/linker/SymbolExtras.c b/rts/linker/SymbolExtras.c index b5a06c662c..7f77d5120a 100644 --- a/rts/linker/SymbolExtras.c +++ b/rts/linker/SymbolExtras.c @@ -77,7 +77,9 @@ int ocAllocateExtras(ObjectCode* oc, int count, int first, int bssSize) /* N.B. We currently can't mark symbol extras as non-executable in this * case. */ size_t n = roundUpToPage(oc->fileSize); - bssSize = roundUpToAlign(bssSize, 8); + // round bssSize up to the nearest page size since we need to ensure that + // symbol_extras is aligned to a page boundary so it can be mprotect'd. + bssSize = roundUpToPage(bssSize); size_t allocated_size = n + bssSize + extras_size; void *new = mmapForLinker(allocated_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS, -1, 0); if (new) { |