From 56ea76b6bf190bffdc07aba90e4b25dfc096027b Mon Sep 17 00:00:00 2001 From: Bernd Schmidt Date: Mon, 11 Apr 2011 13:13:18 +0200 Subject: Fix nommu handling of DT_TEXTREL We have a problem with DT_TEXTREL shared libraries on nommu machines. The dynamic linker's strategy is to map the text segment read-only first, then look for DT_TEXTREL, and use mprotect to change protections if necessary. This fails on nommu, since a nommu kernel can decide to share the memory for private read-only file mappings, and mprotect doesn't (can't) do anything about this sharing. Existing nommu targets apparently have no need for this, but on C6X, we may need to assign library indices at run-time if no --dsbt-index option was passed to the linker at build time. Hence, the following patch, which instead of using mprotect, redoes the mapping with PF_W set. Signed-off-by: Bernd Schmidt --- ldso/ldso/bfin/dl-inlines.h | 41 +++++++++++++++++++++++++++++++++-------- ldso/ldso/bfin/dl-sysdep.h | 2 ++ 2 files changed, 35 insertions(+), 8 deletions(-) (limited to 'ldso/ldso/bfin') diff --git a/ldso/ldso/bfin/dl-inlines.h b/ldso/ldso/bfin/dl-inlines.h index 6524f5edc..969986218 100644 --- a/ldso/ldso/bfin/dl-inlines.h +++ b/ldso/ldso/bfin/dl-inlines.h @@ -88,14 +88,39 @@ __dl_init_loadaddr_hdr (struct elf32_fdpic_loadaddr loadaddr, void *addr, segdata->p_memsz = phdr->p_memsz; #if defined (__SUPPORT_LD_DEBUG__) - { - extern char *_dl_debug; - extern int _dl_debug_file; - if (_dl_debug) - _dl_dprintf(_dl_debug_file, "%i: mapped %x at %x, size %x\n", - loadaddr.map->nsegs-1, - segdata->p_vaddr, segdata->addr, segdata->p_memsz); - } + if (_dl_debug) + _dl_dprintf(_dl_debug_file, "%i: mapped %x at %x, size %x\n", + loadaddr.map->nsegs-1, + segdata->p_vaddr, segdata->addr, segdata->p_memsz); +#endif +} + +/* Replace an existing entry in the load map. */ +static __always_inline void +__dl_update_loadaddr_hdr (struct elf32_fdpic_loadaddr loadaddr, void *addr, + Elf32_Phdr *phdr) +{ + struct elf32_fdpic_loadseg *segdata; + void *oldaddr; + int i; + + for (i = 0; i < loadaddr.map->nsegs; i++) + if (loadaddr.map->segs[i].p_vaddr == phdr->p_vaddr + && loadaddr.map->segs[i].p_memsz == phdr->p_memsz) + break; + if (i == loadaddr.map->nsegs) + _dl_exit (-1); + + segdata = loadaddr.map->segs + i; + oldaddr = (void *)segdata->addr; + _dl_munmap (oldaddr, segdata->p_memsz); + segdata->addr = (Elf32_Addr) addr; + +#if defined (__SUPPORT_LD_DEBUG__) + if (_dl_debug) + _dl_dprintf(_dl_debug_file, "%i: changed mapping %x at %x (old %x), size %x\n", + loadaddr.map->nsegs-1, + segdata->p_vaddr, segdata->addr, oldaddr, segdata->p_memsz); #endif } diff --git a/ldso/ldso/bfin/dl-sysdep.h b/ldso/ldso/bfin/dl-sysdep.h index 50c750990..168e5c89a 100644 --- a/ldso/ldso/bfin/dl-sysdep.h +++ b/ldso/ldso/bfin/dl-sysdep.h @@ -120,6 +120,8 @@ struct funcdesc_ht; #define DL_INIT_LOADADDR_HDR(LOADADDR, ADDR, PHDR) \ (__dl_init_loadaddr_hdr ((LOADADDR), (ADDR), (PHDR), \ dl_init_loadaddr_load_count)) +#define DL_UPDATE_LOADADDR_HDR(LOADADDR, ADDR, PHDR) \ + (__dl_update_loadaddr_hdr ((LOADADDR), (ADDR), (PHDR))) #define DL_LOADADDR_UNMAP(LOADADDR, LEN) \ (__dl_loadaddr_unmap ((LOADADDR), (NULL))) #define DL_LIB_UNMAP(LIB, LEN) \ -- cgit v1.2.3