06 Sep, 2021
1 commit
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fs/binfmt_aout.c: In function ‘load_aout_library’:
fs/binfmt_aout.c:311:27: error: expected ‘)’ before ‘;’ token
311 | MAP_FIXED | MAP_PRIVATE;
| ^
fs/binfmt_aout.c:309:10: error: too few arguments to function ‘vm_mmap’
309 | error = vm_mmap(file, start_addr, ex.a_text + ex.a_data,
| ^~~~~~~
In file included from fs/binfmt_aout.c:12:
include/linux/mm.h:2626:35: note: declared here
2626 | extern unsigned long __must_check vm_mmap(struct file *, unsigned long,
| ^~~~~~~Fix this by reverting the accidental replacement of a comma by a
semicolon.Fixes: 42be8b42535183f8 ("binfmt: don't use MAP_DENYWRITE when loading shared libraries via uselib()")
Reported-by: noreply@ellerman.id.au
Reported-by: Guenter Roeck
Signed-off-by: Geert Uytterhoeven
Signed-off-by: Linus Torvalds
04 Sep, 2021
2 commits
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At exec time when we mmap the new executable via MAP_DENYWRITE we have it
opened via do_open_execat() and already deny_write_access()'ed the file
successfully. Once exec completes, we allow_write_acces(); however,
we set mm->exe_file in begin_new_exec() via set_mm_exe_file() and
also deny_write_access() as long as mm->exe_file remains set. We'll
effectively deny write access to our executable via mm->exe_file
until mm->exe_file is changed -- when the process is removed, on new
exec, or via sys_prctl(PR_SET_MM_MAP/EXE_FILE).Let's remove all usage of MAP_DENYWRITE, it's no longer necessary for
mm->exe_file.In case of an elf interpreter, we'll now only deny write access to the file
during exec. This is somewhat okay, because the interpreter behaves
(and sometime is) a shared library; all shared libraries, especially the
ones loaded directly in user space like via dlopen() won't ever be mapped
via MAP_DENYWRITE, because we ignore that from user space completely;
these shared libraries can always be modified while mapped and executed.
Let's only special-case the main executable, denying write access while
being executed by a process. This can be considered a minor user space
visible change.While this is a cleanup, it also fixes part of a problem reported with
VM_DENYWRITE on overlayfs, as VM_DENYWRITE is effectively unused with
this patch and will be removed next:
"Overlayfs did not honor positive i_writecount on realfile for
VM_DENYWRITE mappings." [1][1] https://lore.kernel.org/r/YNHXzBgzRrZu1MrD@miu.piliscsaba.redhat.com/
Reported-by: Chengguang Xu
Acked-by: "Eric W. Biederman"
Acked-by: Christian König
Signed-off-by: David Hildenbrand -
uselib() is the legacy systemcall for loading shared libraries.
Nowadays, applications use dlopen() to load shared libraries, completely
implemented in user space via mmap().For example, glibc uses MAP_COPY to mmap shared libraries. While this
maps to MAP_PRIVATE | MAP_DENYWRITE on Linux, Linux ignores any
MAP_DENYWRITE specification from user space in mmap.With this change, all remaining in-tree users of MAP_DENYWRITE use it
to map an executable. We will be able to open shared libraries loaded
via uselib() writable, just as we already can via dlopen() from user
space.This is one step into the direction of removing MAP_DENYWRITE from the
kernel. This can be considered a minor user space visible change.Acked-by: "Eric W. Biederman"
Acked-by: Christian König
Signed-off-by: David Hildenbrand
30 Jun, 2021
1 commit
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Ever since commit e9714acf8c43 ("mm: kill vma flag VM_EXECUTABLE and
mm->num_exe_file_vmas"), VM_EXECUTABLE is gone and MAP_EXECUTABLE is
essentially completely ignored. Let's remove all usage of MAP_EXECUTABLE.[akpm@linux-foundation.org: fix blooper in fs/binfmt_aout.c. per David]
Link: https://lkml.kernel.org/r/20210421093453.6904-3-david@redhat.com
Signed-off-by: David Hildenbrand
Acked-by: "Eric W. Biederman"
Reviewed-by: Kees Cook
Cc: Alexander Shishkin
Cc: Alexander Viro
Cc: Arnaldo Carvalho de Melo
Cc: Borislav Petkov
Cc: Catalin Marinas
Cc: Don Zickus
Cc: Feng Tang
Cc: Greg Ungerer
Cc: "H. Peter Anvin"
Cc: Ingo Molnar
Cc: Jiri Olsa
Cc: Kevin Brodsky
Cc: Mark Rutland
Cc: Michal Hocko
Cc: Mike Rapoport
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 May, 2020
3 commits
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There is and has been for a very long time been a lot more going on in
flush_old_exec than just flushing the old state. After the movement
of code from setup_new_exec there is a whole lot more going on than
just flushing the old executables state.Rename flush_old_exec to begin_new_exec to more accurately reflect
what this function does.Reviewed-by: Kees Cook
Reviewed-by: Greg Ungerer
Signed-off-by: "Eric W. Biederman" -
The two functions are now always called one right after the
other so merge them together to make future maintenance easier.Reviewed-by: Kees Cook
Reviewed-by: Greg Ungerer
Signed-off-by: "Eric W. Biederman" -
In 2016 Linus moved install_exec_creds immediately after
setup_new_exec, in binfmt_elf as a cleanup and as part of closing a
potential information leak.Perform the same cleanup for the other binary formats.
Different binary formats doing the same things the same way makes exec
easier to reason about and easier to maintain.Greg Ungerer reports:
> I tested the the whole series on non-MMU m68k and non-MMU arm
> (exercising binfmt_flat) and it all tested out with no problems,
> so for the binfmt_flat changes:
Tested-by: Greg UngererRef: 9f834ec18def ("binfmt_elf: switch to new creds when switching to new mm")
Reviewed-by: Kees Cook
Reviewed-by: Greg Ungerer
Signed-off-by: "Eric W. Biederman"
21 May, 2019
1 commit
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Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the fileThese files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:GPL-2.0-only
Signed-off-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
06 Mar, 2019
1 commit
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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
04 Jan, 2019
1 commit
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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
12 Apr, 2018
1 commit
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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
05 Sep, 2017
1 commit
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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
02 Mar, 2017
1 commit
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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
25 Dec, 2016
1 commit
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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
29 May, 2016
1 commit
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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
28 May, 2016
1 commit
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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
24 May, 2016
1 commit
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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
20 Nov, 2014
1 commit
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Signed-off-by: Al Viro
09 Oct, 2014
1 commit
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... rather than doing that in the guts of ->load_binary().
[updated to fix the bug spotted by Shentino - for SIGSEGV we really need
something stronger than send_sig_info(); again, better do that in one place]Signed-off-by: Al Viro
09 Nov, 2013
2 commits
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Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
25 Oct, 2013
1 commit
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Signed-off-by: Al Viro
11 Jul, 2013
1 commit
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Since all architectures have been converted to use vm_unmapped_area(),
there is no remaining use for the free_area_cache.Signed-off-by: Michel Lespinasse
Acked-by: Rik van Riel
Cc: "James E.J. Bottomley"
Cc: "Luck, Tony"
Cc: Benjamin Herrenschmidt
Cc: David Howells
Cc: Helge Deller
Cc: Ivan Kokshaysky
Cc: Matt Turner
Cc: Paul Mackerras
Cc: Richard Henderson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 May, 2013
1 commit
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Pull VFS updates from Al Viro,
Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).7kloc removed.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
don't bother with deferred freeing of fdtables
proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
proc: Make the PROC_I() and PDE() macros internal to procfs
proc: Supply a function to remove a proc entry by PDE
take cgroup_open() and cpuset_open() to fs/proc/base.c
ppc: Clean up scanlog
ppc: Clean up rtas_flash driver somewhat
hostap: proc: Use remove_proc_subtree()
drm: proc: Use remove_proc_subtree()
drm: proc: Use minor->index to label things, not PDE->name
drm: Constify drm_proc_list[]
zoran: Don't print proc_dir_entry data in debug
reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
proc: Supply an accessor for getting the data from a PDE's parent
airo: Use remove_proc_subtree()
rtl8192u: Don't need to save device proc dir PDE
rtl8187se: Use a dir under /proc/net/r8180/
proc: Add proc_mkdir_data()
proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
proc: Move PDE_NET() to fs/proc/proc_net.c
...
01 May, 2013
1 commit
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Cleanup. Every linux_binfmt->core_dump() sets PF_DUMPCORE, move this into
zap_threads() called by do_coredump().Signed-off-by: Oleg Nesterov
Acked-by: Mandeep Singh Baines
Cc: Neil Horman
Cc: "Rafael J. Wysocki"
Cc: Tejun Heo
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Apr, 2013
1 commit
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switch binfmts that use ->read() to that (and to kernel_read()
in several cases in binfmt_flat - sure, it's nommu, but still,
doing ->read() into kmalloc'ed buffer...)Signed-off-by: Al Viro
23 Feb, 2013
1 commit
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Signed-off-by: Al Viro
29 Nov, 2012
1 commit
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Signed-off-by: Al Viro
06 Oct, 2012
2 commits
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This is a preparatory patch for the introduction of NT_SIGINFO elf note.
With this patch we pass "siginfo_t *siginfo" instead of "int signr" to
do_coredump() and put it into coredump_params. It will be used by the
next patch. Most changes are simple s/signr/siginfo->si_signo/.Signed-off-by: Denys Vlasenko
Reviewed-by: Oleg Nesterov
Cc: Amerigo Wang
Cc: "Jonathan M. Foote"
Cc: Roland McGrath
Cc: Pedro Alves
Cc: Fengguang Wu
Cc: Stephen Rothwell
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Adds an expert Kconfig option, CONFIG_COREDUMP, which allows disabling of
core dump. This saves approximately 2.6k in the compiled kernel, and
complements CONFIG_ELF_CORE, which now depends on it.CONFIG_COREDUMP also disables coredump-related sysctls, except for
suid_dumpable and related functions, which are necessary for ptrace.[akpm@linux-foundation.org: fix binfmt_aout.c build]
Signed-off-by: Alex Kelly
Reviewed-by: Josh Triplett
Acked-by: Serge Hallyn
Acked-by: Kees Cook
Cc: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Apr, 2012
2 commits
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This continues the theme started with vm_brk() and vm_munmap():
vm_mmap() does the same thing as do_mmap(), but additionally does the
required VM locking.This uninlines (and rewrites it to be clearer) do_mmap(), which sadly
duplicates it in mm/mmap.c and mm/nommu.c. But that way we don't have
to export our internal do_mmap_pgoff() function.Some day we hopefully don't have to export do_mmap() either, if all
modular users can become the simpler vm_mmap() instead. We're actually
very close to that already, with the notable exception of the (broken)
use in i810, and a couple of stragglers in binfmt_elf.Signed-off-by: Linus Torvalds
-
It does the same thing as "do_brk()", except it handles the VM locking
too.It turns out that all external callers want that anyway, so we can make
do_brk() static to just mm/mmap.c while at it.Signed-off-by: Linus Torvalds
29 Mar, 2012
1 commit
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Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:perl -p -i -e 's!^#\s*include\s*.*\n!!' `grep -Irl '^#\s*include\s*' *`
Signed-off-by: David Howells
21 Mar, 2012
2 commits
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Signed-off-by: Al Viro
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Just don't pass NULL to it - nobody does, anyway.
Signed-off-by: Al Viro
06 Mar, 2012
1 commit
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Signed-off-by: Al Viro
Signed-off-by: Linus Torvalds
15 Oct, 2010
1 commit
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akiphie points out that a.out core-dumps have that odd task struct
dumping that was never used and was never really a good idea (it goes
back into the mists of history, probably the original core-dumping
code). Just remove it.Also do the access_ok() check on dump_write(). It probably doesn't
matter (since normal filesystems all seem to do it anyway), but he
points out that it's normally done by the VFS layer, so ...[ I suspect that we should possibly do "vfs_write()" instead of
calling ->write directly. That also does the whole fsnotify and write
statistics thing, which may or may not be a good idea. ]And just to be anal, do this all for the x86-64 32-bit a.out emulation
code too, even though it's not enabled (and won't currently even
compile)Reported-by: akiphie
Signed-off-by: Linus Torvalds
30 Mar, 2010
1 commit
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…it slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
25 Mar, 2010
1 commit
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fs/binfmt_aout.c: In function `aout_core_dump':
fs/binfmt_aout.c:125: warning: passing argument 2 of `dump_write' makes pointer from integer without a cast
include/linux/coredump.h:12: note: expected `const void *' but argument is of type `long unsigned int'
fs/binfmt_aout.c:132: warning: passing argument 2 of `dump_write' makes pointer from integer without a cast
include/linux/coredump.h:12: note: expected `const void *' but argument is of type `long unsigned int'due to dump_write() expecting a user void *. Fold casts into the
START_DATA/START_STACK macros and shut up the warnings.Signed-off-by: Borislav Petkov
Cc: Daisuke HATAYAMA
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Mar, 2010
1 commit
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My next patch will replace ELF_CORE_EXTRA_* macros by functions, putting
them into other newly created *.c files. Then, each files will contain
dump_write(), where each pair of binfmt_*.c and elfcore.c should be the
same. So, this patch moves them into a header file with dump_seek().
Also, the patch deletes confusing DUMP_WRITE macros in each files.Signed-off-by: Daisuke HATAYAMA
Cc: "Luck, Tony"
Cc: Jeff Dike
Cc: David Howells
Cc: Greg Ungerer
Cc: Roland McGrath
Cc: Oleg Nesterov
Cc: Ingo Molnar
Cc: Alexander Viro
Cc: Andi Kleen
Cc: Alan Cox
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
