From cadaf1336332ca7bcdfe4a400776e5782a20e26d Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 28 Oct 2015 07:49:44 -0700 Subject: [PATCH] Keep only ELF_RTYPE_CLASS_{PLT|COPY} bits for prelink prelink runs ld.so with the environment variable LD_TRACE_PRELINKING set to dump the relocation type class from _dl_debug_bindings. prelink has the following relocation type classes: #define RTYPE_CLASS_VALID 8 #define RTYPE_CLASS_PLT (8|1) #define RTYPE_CLASS_COPY (8|2) #define RTYPE_CLASS_TLS (8|4) where ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA has a conflict with RTYPE_CLASS_TLS. Since prelink only uses ELF_RTYPE_CLASS_PLT and ELF_RTYPE_CLASS_COPY bits, we should clear the other bits when the DL_DEBUG_PRELINK bit is set. [BZ #19178] * elf/dl-lookup.c (RTYPE_CLASS_VALID): New. (RTYPE_CLASS_PLT): Likewise. (RTYPE_CLASS_COPY): Likewise. (RTYPE_CLASS_TLS): Likewise. (_dl_debug_bindings): Use RTYPE_CLASS_TLS and RTYPE_CLASS_VALID to set relocation type class for DL_DEBUG_PRELINK. Keep only ELF_RTYPE_CLASS_PLT and ELF_RTYPE_CLASS_COPY bits for DL_DEBUG_PRELINK. Upstream-Status: submitted (https://sourceware.org/bugzilla/show_bug.cgi?id=19178) Signed-off-by: Mark Hatle --- elf/dl-lookup.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c index 581fb20..6ae6cc3 100644 --- a/elf/dl-lookup.c +++ b/elf/dl-lookup.c @@ -1016,6 +1016,18 @@ _dl_debug_bindings (const char *undef_name, struct link_map *undef_map, #ifdef SHARED if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) { +/* ELF_RTYPE_CLASS_XXX must match RTYPE_CLASS_XXX used by prelink with + LD_TRACE_PRELINKING. */ +#define RTYPE_CLASS_VALID 8 +#define RTYPE_CLASS_PLT (8|1) +#define RTYPE_CLASS_COPY (8|2) +#define RTYPE_CLASS_TLS (8|4) +#if ELF_RTYPE_CLASS_PLT != 0 && ELF_RTYPE_CLASS_PLT != 1 +# error ELF_RTYPE_CLASS_PLT must be 0 or 1! +#endif +#if ELF_RTYPE_CLASS_COPY != 0 && ELF_RTYPE_CLASS_COPY != 2 +# error ELF_RTYPE_CLASS_COPY must be 0 or 2! +#endif int conflict = 0; struct sym_val val = { NULL, NULL }; @@ -1071,12 +1083,17 @@ _dl_debug_bindings (const char *undef_name, struct link_map *undef_map, if (value->s) { + /* Keep only ELF_RTYPE_CLASS_PLT and ELF_RTYPE_CLASS_COPY + bits since since prelink only uses them. */ + type_class &= ELF_RTYPE_CLASS_PLT | ELF_RTYPE_CLASS_COPY; if (__glibc_unlikely (ELFW(ST_TYPE) (value->s->st_info) == STT_TLS)) - type_class = 4; + /* Clear the RTYPE_CLASS_VALID bit in RTYPE_CLASS_TLS. */ + type_class = RTYPE_CLASS_TLS & ~RTYPE_CLASS_VALID; else if (__glibc_unlikely (ELFW(ST_TYPE) (value->s->st_info) == STT_GNU_IFUNC)) - type_class |= 8; + /* Set the RTYPE_CLASS_VALID bit. */ + type_class |= RTYPE_CLASS_VALID; } if (conflict -- 1.9.3