kernel/fs/binfmt_aout.c, branch linux-5.1.y

a.out: remove core dumping support

2019-03-05T18:00:35Z

We're (finally) phasing out a.out support for good. As Borislav Petkov points out, we've supported ELF binaries for about 25 years by now, and coredumping in particular has bitrotted over the years. None of the tool chains even support generating a.out binaries any more, and the plan is to deprecate a.out support entirely for the kernel. But I want to start with just removing the core dumping code, because I can still imagine that somebody actually might want to support a.out as a simpler biinary format. Particularly if you generate some random binaries on the fly, ELF is a much more complicated format (admittedly ELF also does have a lot of toolchain support, mitigating that complexity a lot and you really should have moved over in the last 25 years). So it's at least somewhat possible that somebody out there has some workflow that still involves generating and running a.out executables. In contrast, it's very unlikely that anybody depends on debugging any legacy a.out core files. But regardless, I want this phase-out to be done in two steps, so that we can resurrect a.out support (if needed) without having to resurrect the core file dumping that is almost certainly not needed. Jann Horn pointed to the file that my first trivial cut at this had missed. And Alan Cox points out that the a.out binary loader _could_ be done in user space if somebody wants to, but we might keep just the loader in the kernel if somebody really wants it, since the loader isn't that big and has no really odd special cases like the core dumping does. Acked-by: Borislav Petkov Cc: Alan Cox Cc: Jann Horn Cc: Richard Weinberger Signed-off-by: Linus Torvalds

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57Z

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds

exec: introduce finalize_exec() before start_thread()

2018-04-11T17:28:37Z

Provide a final callback into fs/exec.c before start_thread() takes over, to handle any last-minute changes, like the coming restoration of the stack limit. Link: http://lkml.kernel.org/r/1518638796-20819-3-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook Cc: Andy Lutomirski Cc: Ben Hutchings Cc: Ben Hutchings Cc: Brad Spengler Cc: Greg KH Cc: Hugh Dickins Cc: "Jason A. Donenfeld" Cc: Laura Abbott Cc: Michal Hocko Cc: Oleg Nesterov Cc: Rik van Riel Cc: Willy Tarreau Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs: fix kernel_read prototype

2017-09-04T23:05:15Z

Use proper ssize_t and size_t types for the return value and count argument, move the offset last and make it an in/out argument like all other read/write helpers, and make the buf argument a void pointer to get rid of lots of casts in the callers. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:36Z

We are going to split out of , which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder file that just maps to to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

Replace with globally

2016-12-24T19:46:01Z

This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*' sed -i -e "s!$PATT!#include !" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro Signed-off-by: Linus Torvalds

fs: fix binfmt_aout.c build error

2016-05-28T23:34:59Z

Various builds (such as i386:allmodconfig) fail with fs/binfmt_aout.c:133:2: error: expected identifier or '(' before 'return' fs/binfmt_aout.c:134:1: error: expected identifier or '(' before '}' token [ Oops. My bad, I had stupidly thought that "allmodconfig" covered this on x86-64 too, but it obviously doesn't. Egg on my face. - Linus ] Fixes: 5d22fc25d4fc ("mm: remove more IS_ERR_VALUE abuses") Signed-off-by: Guenter Roeck Signed-off-by: Linus Torvalds

mm: remove more IS_ERR_VALUE abuses

2016-05-27T22:57:31Z

The do_brk() and vm_brk() return value was "unsigned long" and returned the starting address on success, and an error value on failure. The reasons are entirely historical, and go back to it basically behaving like the mmap() interface does. However, nobody actually wanted that interface, and it causes totally pointless IS_ERR_VALUE() confusion. What every single caller actually wants is just the simpler integer return of zero for success and negative error number on failure. So just convert to that much clearer and more common calling convention, and get rid of all the IS_ERR_VALUE() uses wrt vm_brk(). Signed-off-by: Linus Torvalds

mm, aout: handle vm_brk failures

2016-05-24T00:04:14Z

vm_brk is allowed to fail but load_aout_binary simply ignores the error and happily continues. I haven't noticed any problem from that in real life but later patches will make the failure more likely because vm_brk will become killable (resp. mmap_sem for write waiting will become killable) so we should be more careful now. The error handling should be quite straightforward because there are calls to vm_mmap which check the error properly already. The only notable exception is set_brk which is called after beyond_if label. But nothing indicates that we cannot move it above set_binfmt as the two do not depend on each other and fail before we do set_binfmt and alter reference counting. Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Alexander Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

assorted conversions to %p[dD]

2014-11-19T18:01:20Z

Signed-off-by: Al Viro