Commit 9f40cf6c authored by Ben Gamari's avatar Ben Gamari 🐢 Committed by Marge Bot

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.
parent fc963932
Pipeline #27662 canceled with stages
......@@ -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) {
......
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