From 7a2ff73d68079d4a7f23957712e566865d4491d6 Mon Sep 17 00:00:00 2001 From: Ed Maste Date: Tue, 5 Jan 2016 15:52:16 +0000 Subject: rtld: populate DT_DEBUG iff DYNAMIC segment is writable MIPS has/had a read-only DYNAMIC segment, and uses an extra level of indirection (through MIPS_RLD_MAP) to locate the debugger rendezvous data. Some linkers (e.g. LLVM's lld) may produce MIPS binaries with a writable DYNAMIC segment, which would allow us to eventually drop a special case. Therefore, instead of hardcoding knowledge that DYNAMIC is not writable on MIPS just check the permissions on the segment. Reviewed by: kib MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D4791 --- libexec/rtld-elf/rtld.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'libexec') diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c index 66edc157d393..6daef2d13405 100644 --- a/libexec/rtld-elf/rtld.c +++ b/libexec/rtld-elf/rtld.c @@ -1144,13 +1144,13 @@ digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, * is mapped read-only. DT_MIPS_RLD_MAP is used instead. */ -#ifndef __mips__ case DT_DEBUG: + if (!obj->writable_dynamic) + break; if (!early) dbg("Filling in DT_DEBUG entry"); ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; break; -#endif case DT_FLAGS: if (dynp->d_un.d_val & DF_ORIGIN) @@ -1331,6 +1331,8 @@ digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) break; case PT_DYNAMIC: + if (ph->p_flags & PROT_WRITE) + obj->writable_dynamic = true; obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); break; -- cgit v1.2.3