From 6fc30c2493fcfedec89e45088bea87766a1e3286 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 17 Sep 2015 08:05:34 +0000 Subject: [PATCH] remove old dlstart stage-2 symbolic lookup code; add new generic this new generic version of the stage-2 function lookup should work for any arch where static data is accessible via got-relative or pc-relative addressing, using approximately the technique described in the log message for commit 2907afb8dbd4c1d34825c3c9bd2b41564baca210. since all the mips-like archs that need got slots fo access static data have already transitioned to the new stage chaining scheme, the old dynamic symbol lookup code is now removed. aarch64, arm, and sh have not yet transitioned; with this commit, they are now using the new generic code. --- src/ldso/dlstart.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/src/ldso/dlstart.c b/src/ldso/dlstart.c index eb919ab4..a968baab 100644 --- a/src/ldso/dlstart.c +++ b/src/ldso/dlstart.c @@ -9,6 +9,14 @@ #include "crt_arch.h" +#ifndef GETFUNCSYM +#define GETFUNCSYM(fp, sym, got) do { \ + __attribute__((__visibility__("hidden"))) void sym(); \ + static void (*static_func_ptr)() = sym; \ + __asm__ __volatile__ ( "" : "+m"(static_func_ptr) : : "memory"); \ + *(fp) = static_func_ptr; } while(0) +#endif + __attribute__((__visibility__("hidden"))) void _dlstart_c(size_t *sp, size_t *dynv) { @@ -74,23 +82,9 @@ void _dlstart_c(size_t *sp, size_t *dynv) *rel_addr = (size_t)base + rel[2]; } -#ifndef GETFUNCSYM - const char *strings = (void *)(base + dyn[DT_STRTAB]); - const Sym *syms = (void *)(base + dyn[DT_SYMTAB]); - - /* Call dynamic linker stage-2, __dls2 */ - for (i=0; ;i++) { - const char *s = strings + syms[i].st_name; - if (s[0]=='_' && s[1]=='_' && s[2]=='d' - && s[3]=='l' && s[4]=='s' && s[5]=='2' && !s[6]) - break; - } - ((stage2_func)(base + syms[i].st_value))(base, sp); -#else stage2_func dls2; GETFUNCSYM(&dls2, __dls2, base+dyn[DT_PLTGOT]); dls2(base, sp); -#endif } #endif -- 2.25.1