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author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2022-09-02 14:07:06 +0100 |
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committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2022-10-12 14:22:03 +0100 |
commit | e841326457b09c3d6af9634fe918a47d61113b04 (patch) | |
tree | 55e969bbd963aa85f728d60dcd3060f53738a745 | |
parent | a1d26f7b1d8d78588c6fd301515a07f92883b150 (diff) | |
download | glibc-e841326457b09c3d6af9634fe918a47d61113b04.tar.gz glibc-e841326457b09c3d6af9634fe918a47d61113b04.tar.xz glibc-e841326457b09c3d6af9634fe918a47d61113b04.zip |
cheri: elf: Use RW permissions for l_ld when needed
The dynamic section of an executable needs to be written to set the DT_DEBUG entry for debuggers (unless the target has some other place to store r_debug). For this reason we make l_ld writable whenever the dynamic section is writable. The ld.so l_ld is kept RX, since it does not have DT_DEBUG. (Note: relocating the dynamic section is not allowed on cheri and that's the only other reason glibc would write to it.)
-rw-r--r-- | elf/dl-load.c | 4 | ||||
-rw-r--r-- | elf/rtld.c | 4 |
2 files changed, 6 insertions, 2 deletions
diff --git a/elf/dl-load.c b/elf/dl-load.c index 367b8cdab1..192ad4f7c9 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1276,7 +1276,9 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, } if (l->l_ld != 0) - l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr); + l->l_ld = (ElfW(Dyn) *) (l->l_ld_readonly + ? dl_rx_ptr (l, (elfptr_t) l->l_ld) + : dl_rw_ptr (l, (elfptr_t) l->l_ld)); elf_get_dynamic_info (l, false, false); diff --git a/elf/rtld.c b/elf/rtld.c index 007e938b90..fcb8b9e888 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1181,8 +1181,10 @@ rtld_setup_main_map (struct link_map *main_map) case PT_DYNAMIC: /* This tells us where to find the dynamic section, which tells us everything we need to do. */ - main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr; main_map->l_ld_readonly = (ph->p_flags & PF_W) == 0; + main_map->l_ld = (void *) (main_map->l_ld_readonly + ? dl_rx_ptr (main_map, ph->p_vaddr) + : dl_rw_ptr (main_map, ph->p_vaddr)); break; case PT_INTERP: /* This "interpreter segment" was used by the program loader to |