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fix dl_iterate_phdr dlpi_tls_data reporting to match spec

dl_iterate_phdr was wrongly reporting the address of the DSO's PT_TLS
image rather than the calling thread's instance of the TLS. the man
page, which is essentially normative for a nonstandard function of
this sort, clearly specifies the latter. it does not clarify where
exactly within/relative-to the image the pointer should point, but the
reasonable thing to do is match the ABI's DTP offset, and this seems
to be what other implementations do.
Rich Felker 4 years ago
parent
commit
521b4d27a0
2 changed files with 3 additions and 2 deletions
  1. 1 1
      ldso/dynlink.c
  2. 2 1
      src/ldso/dl_iterate_phdr.c

+ 1 - 1
ldso/dynlink.c

@@ -2331,7 +2331,7 @@ int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void
 		info.dlpi_adds      = gencnt;
 		info.dlpi_subs      = 0;
 		info.dlpi_tls_modid = current->tls_id;
-		info.dlpi_tls_data  = current->tls.image;
+		info.dlpi_tls_data = __tls_get_addr((tls_mod_off_t[]){current->tls_id,0});
 
 		ret = (callback)(&info, sizeof (info), data);
 

+ 2 - 1
src/ldso/dl_iterate_phdr.c

@@ -1,5 +1,6 @@
 #include <elf.h>
 #include <link.h>
+#include "pthread_impl.h"
 #include "libc.h"
 
 #define AUX_CNT 38
@@ -35,7 +36,7 @@ static int static_dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size
 	info.dlpi_subs  = 0;
 	if (tls_phdr) {
 		info.dlpi_tls_modid = 1;
-		info.dlpi_tls_data = (void *)(base + tls_phdr->p_vaddr);
+		info.dlpi_tls_data = __tls_get_addr((tls_mod_off_t[]){1,0});
 	} else {
 		info.dlpi_tls_modid = 0;
 		info.dlpi_tls_data = 0;