The patch titled
fdpic: ignore the loader's PT_GNU_STACK when calculating the stack size
has been added to the -mm tree. Its filename is
fdpic-ignore-the-loaders-pt_gnu_stack-when-calculating-the-stack-size.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: fdpic: ignore the loader's PT_GNU_STACK when calculating the stack size
From: David Howells <dhowells@xxxxxxxxxx>
Ignore the loader's PT_GNU_STACK when calculating the stack size, and only
consider the executable's PT_GNU_STACK, assuming the executable has one.
Currently the behaviour is to take the largest stack size and use that,
but that means you can't reduce the stack size in the executable. The
loader's stack size should probably only be used when executing the loader
directly.
WARNING: This patch is slightly dangerous - it may render a system
inoperable if the loader's stack size is larger than that of important
executables, and the system relies unknowingly on this increasing the size
of the stack.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Mike Frysinger <vapier@xxxxxxxxxx>
Acked-by: Paul Mundt <lethal@xxxxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/binfmt_elf_fdpic.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff -puN fs/binfmt_elf_fdpic.c~fdpic-ignore-the-loaders-pt_gnu_stack-when-calculating-the-stack-size fs/binfmt_elf_fdpic.c
--- a/fs/binfmt_elf_fdpic.c~fdpic-ignore-the-loaders-pt_gnu_stack-when-calculating-the-stack-size
+++ a/fs/binfmt_elf_fdpic.c
@@ -283,20 +283,23 @@ static int load_elf_fdpic_binary(struct
}
stack_size = exec_params.stack_size;
- if (stack_size < interp_params.stack_size)
- stack_size = interp_params.stack_size;
-
if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
executable_stack = EXSTACK_ENABLE_X;
else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
executable_stack = EXSTACK_DISABLE_X;
- else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
- executable_stack = EXSTACK_ENABLE_X;
- else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
- executable_stack = EXSTACK_DISABLE_X;
else
executable_stack = EXSTACK_DEFAULT;
+ if (stack_size == 0) {
+ stack_size = interp_params.stack_size;
+ if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
+ executable_stack = EXSTACK_ENABLE_X;
+ else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
+ executable_stack = EXSTACK_DISABLE_X;
+ else
+ executable_stack = EXSTACK_DEFAULT;
+ }
+
retval = -ENOEXEC;
if (stack_size == 0)
goto error;
_
Patches currently in -mm which might be from dhowells@xxxxxxxxxx are
linux-next.patch
flat-fix-uninitialized-ptr-with-shared-libs.patch
mm-count-only-reclaimable-lru-pages-v2.patch
include-linux-credh-work-around-gcc-424-warning-in-get_cred.patch
frv-duplicate-output_buffer-of-e03.patch
do_wait-wakeup-optimization-change-__wake_up_parent-to-use-filtered-wakeup-selinux_bprm_committed_creds-use-__wake_up_parent.patch
elf-clean-up-fill_note_info.patch
elf-clean-up-fill_note_info-fix.patch
fdpic-ignore-the-loaders-pt_gnu_stack-when-calculating-the-stack-size.patch
flat-use-is_err_value-helper-macro.patch
mutex-subsystem-synchro-test-module.patch
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