[hurd,commited] hurd: Avoid overzealous shared objects constraints

Message ID 20211231172317.1588988-1-samuel.thibault@ens-lyon.org
State Committed, archived
Headers
Series [hurd,commited] hurd: Avoid overzealous shared objects constraints |

Checks

Context Check Description
dj/TryBot-apply_patch fail Patch failed to apply to master at the time it was sent
dj/TryBot-32bit fail Patch series failed to apply

Commit Message

Samuel Thibault Dec. 31, 2021, 5:23 p.m. UTC
  407765e9f24f ("hurd: Fix ELF_MACHINE_USER_ADDRESS_MASK value") switched
ELF_MACHINE_USER_ADDRESS_MASK from 0xf8000000UL to 0xf0000000UL to let
libraries etc. get loaded at 0x08000000. But
ELF_MACHINE_USER_ADDRESS_MASK is actually only meaningful for the main
program anyway, so keep it at 0xf8000000UL to prevent the program loader
from putting ld.so beyond 0x08000000. And conversely, drop the use of
ELF_MACHINE_USER_ADDRESS_MASK for shared objects, which don't need any
constraints since the program will have already be loaded by then.
---
 sysdeps/i386/dl-machine.h     | 2 +-
 sysdeps/mach/hurd/dl-sysdep.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)
  

Patch

diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
index 2f0dbc27a9..b5a5dd0983 100644
--- a/sysdeps/i386/dl-machine.h
+++ b/sysdeps/i386/dl-machine.h
@@ -117,7 +117,7 @@  elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
 
 /* Mask identifying addresses reserved for the user program,
    where the dynamic linker should not map anything.  */
-#define ELF_MACHINE_USER_ADDRESS_MASK	0xf0000000UL
+#define ELF_MACHINE_USER_ADDRESS_MASK	0xf8000000UL
 
 /* Initial entry point code for the dynamic linker.
    The C function `_dl_start' is the real entry point;
diff --git a/sysdeps/mach/hurd/dl-sysdep.c b/sysdeps/mach/hurd/dl-sysdep.c
index 968a58f668..b1a151abc1 100644
--- a/sysdeps/mach/hurd/dl-sysdep.c
+++ b/sysdeps/mach/hurd/dl-sysdep.c
@@ -476,7 +476,7 @@  __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset)
 
   mapaddr = (vm_address_t) addr;
   err = __vm_map (__mach_task_self (),
-		  &mapaddr, (vm_size_t) len, ELF_MACHINE_USER_ADDRESS_MASK,
+		  &mapaddr, (vm_size_t) len, 0,
 		  !(flags & MAP_FIXED),
 		  memobj_rd,
 		  (vm_offset_t) offset,
@@ -491,7 +491,7 @@  __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset)
       if (! err)
 	err = __vm_map (__mach_task_self (),
 			&mapaddr, (vm_size_t) len,
-			ELF_MACHINE_USER_ADDRESS_MASK,
+			0,
 			!(flags & MAP_FIXED),
 			memobj_rd, (vm_offset_t) offset,
 			flags & (MAP_COPY|MAP_PRIVATE),