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| author | Rich Felker <dalias@aerifal.cx> | 2012-01-23 02:02:59 -0500 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2012-01-23 02:02:59 -0500 |
| commit | e12fe65c928f038fb8db0caddcf535ab0a980c58 (patch) | |
| tree | 0ad98e45dd5ba4213fe7f7e386669ba2bc7f2e2d | |
| parent | c82f4a32ec694903a37d3f9e48da52486a470aa2 (diff) | |
| download | musl-e12fe65c928f038fb8db0caddcf535ab0a980c58.tar.gz musl-e12fe65c928f038fb8db0caddcf535ab0a980c58.tar.xz musl-e12fe65c928f038fb8db0caddcf535ab0a980c58.zip | |
dynamic linker support for PIE binaries (position-independent main program)
even with this change, PIE will not work yet due to deficiencies in the crt1.o startup code.
| -rw-r--r-- | src/ldso/dynlink.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index e1c2ad7d..df54230c 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -511,10 +511,13 @@ void *__dynlink(int argc, char **argv) ehdr->e_phnum, ehdr->e_phentsize)); decode_dyn(lib); - /* Assume base address of 0 for the main program. This is not - * valid for PIE code; we will have to search the PHDR to get - * the correct load address in the PIE case (not yet supported). */ + /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */ app->base = 0; + phdr = (void *)aux[AT_PHDR]; + for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) { + if (phdr->p_type == PT_PHDR) + app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr); + } app->name = argv[0]; app->global = 1; app->dynv = (void *)(app->base + find_dyn( |