зеркало из https://github.com/mozilla/gecko-dev.git
29e5c3b9dd
In bug 1470701, we added a dummy global variable so that it ends up in the bss section, making it large enough for two pointers. Unfortunately, in some cases, the symbol is eliminated by the linker because it is unused. So we try to ensure it stays there. Differential Revision: https://phabricator.services.mozilla.com/D11257 --HG-- extra : moz-landing-system : lando |
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| .. | ||
| inject | ||
| Makefile.in | ||
| README | ||
| dummy.c | ||
| elf.cpp | ||
| elfhack.cpp | ||
| elfxx.h | ||
| inject.c | ||
| moz.build | ||
| test-array.c | ||
| test-ctors.c | ||
| test.c | ||
README
Elfhack is a program to optimize ELF binaries for size and cold startup speed. Presently, it is quite experimental, though it works well for the target it was created for: Firefox's libxul.so. Elfhack currently only does one thing: packing dynamic relocations ; which ends up being a quite complex task, that can be summarized this way: - Remove RELATIVE relocations from the .rel.dyn/.rela.dyn section. - Inject a small code able to apply relative relocations "by hand" after the .rel.dyn/.rela.dyn section. - Inject a section containing relocative relocations in a different and more packed format, after the small code. - Register the small code as DT_INIT function. Make the small code call what was initially the DT_INIT function, if there was one. - Remove the hole between the new section containing relative relocations and the following sections, adjusting offsets and base addresses accordingly. - Adjust PT_LOAD entries to fit new offsets, and add an additional PT_LOAD entry when that is necessary to handle the discrepancy between offsets and base addresses, meaning the section offsets may yet again need adjustments. - Adjust various DT_* dynamic tags to fit the new ELF layout. - Adjust section headers. - Adjust ELF headers. See http://glandium.org/blog/?p=1177#relocations for some figures.