From 18c0e02e2bd53ceedbb843b06ff90890f1c734b0 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 31 Oct 2012 21:27:48 -0400 Subject: add dl_iterate_phdr interface patches by Alex Caudill (npx). the dynamic-linked version is almost identical to the final submitted patch; I just added a couple missing lines for saving the phdr address when the dynamic linker is invoked directly to run a program, and removed a couple to avoid introducing another unnecessary type. the static-linked version is based on npx's draft. it could use some improvements which are contingent on the startup code saving some additional information for later use. --- src/ldso/dl_iterate_phdr.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 src/ldso/dl_iterate_phdr.c (limited to 'src/ldso/dl_iterate_phdr.c') diff --git a/src/ldso/dl_iterate_phdr.c b/src/ldso/dl_iterate_phdr.c new file mode 100644 index 00000000..49b321a0 --- /dev/null +++ b/src/ldso/dl_iterate_phdr.c @@ -0,0 +1,43 @@ +#ifndef SHARED + +#include +#include +#include "libc.h" + +#define AUX_CNT 38 + +int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data) +{ + unsigned char *p; + ElfW(Phdr) *phdr, *tls_phdr=0; + size_t base = 0; + size_t n; + struct dl_phdr_info info; + size_t i, aux[AUX_CNT]; + + for (i=0; libc.auxv[i]; i+=2) + if (libc.auxv[i]p_type == PT_PHDR) + base = aux[AT_PHDR] - phdr->p_vaddr; + if (phdr->p_type == PT_TLS) + tls_phdr = phdr; + } + info.dlpi_addr = base; + info.dlpi_name = "/proc/self/exe"; + info.dlpi_phdr = (void *)aux[AT_PHDR]; + info.dlpi_phnum = aux[AT_PHNUM]; + info.dlpi_adds = 0; + info.dlpi_subs = 0; + if (tls_phdr) { + info.dlpi_tls_modid = 1; + info.dlpi_tls_data = (void *)(base + tls_phdr->p_vaddr); + } else { + info.dlpi_tls_modid = 0; + info.dlpi_tls_data = 0; + } + return (callback)(&info, sizeof (info), data); +} +#endif -- cgit v1.2.1