[PATCH] D28267: ELF: Round p_memsz of the PT_GNU_RELRO program header up to the page size.

[Ed Maste via Phabricator via llvm-commits]

emaste added inline comments.


================
Comment at: lld/ELF/Writer.cpp:1452-1453
       P.p_align = 1;
+      // The glibc dynamic loader rounds the size down, so we need to round up
+      // to protect the last page.
+      P.p_memsz = alignTo(P.p_memsz, Config->MaxPageSize);
----------------
For reference the FreeBSD rtld algorithm is:
```
            obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
            obj->relro_size = round_page(ph->p_memsz);
```
https://svnweb.freebsd.org/base/head/libexec/rtld-elf/rtld.c?annotate=310422#l1334


https://reviews.llvm.org/D28267