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2016-07-28binfmt_flat: allow compressed flat binary format to work on MMU systemsNicolas Pitre
Let's take the simple and obvious approach by decompressing the binary into a kernel buffer and then copying it to user space. Those who are looking for top performance on an MMU system are unlikely to choose this executable format anyway. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-07-28binfmt_flat: add MMU-specific supportNicolas Pitre
Not much else to do at this point except for the different stack setups. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-07-28binfmt_flat: update libraries' data segment pointer with userspace accessorsNicolas Pitre
This is needed on systems with a MMU. This also gets rid of the strangest C code I've seen lateli i.e. an integer indexed with a pointer value within square brackets. That really looked backwards. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-07-28binfmt_flat: use clear_user() rather than memset() to clear .bssNicolas Pitre
This is needed on systems with a MMU. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-07-28binfmt_flat: use proper user space accessors with old relocs codeNicolas Pitre
Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-07-25binfmt_flat: use proper user space accessors with relocs processing codeNicolas Pitre
Relocs are fixed up in place in user space memory. The appropriate accessors are required for this code to work with an active MMU. The architecture specific handlers flat_get_addr_from_rp() and flat_put_addr_at_rp() for ARM and M68K are adjusted with separate patches. SuperH and Xtensa are left out as they doesn't implement __get_user_unaligned() and __put_user_unaligned() yet. The other architectures that use BFLT don't have any MMU. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-07-25binfmt_flat: clean up create_flat_tables() and stack accessesNicolas Pitre
In addition to better code clarity, this brings proper usage of user memory accessors everywhere the stack is touched. This is essential for making this work on MMU systems. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-07-25binfmt_flat: use generic transfer_args_to_stack()Nicolas Pitre
This gets rid of the rather ugly, open coded and suboptimal copy code. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-07-25binfmt_flat: prevent kernel dammage from corrupted executable headersNicolas Pitre
Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-07-25binfmt_flat: convert printk invocations to their modern formNicolas Pitre
Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-07-25binfmt_flat: assorted cleanupsNicolas Pitre
Remove excessive casts, do some code grouping, fix most important checkpatch.pl complaints, etc. No functional changes. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2016-05-27remove lots of IS_ERR_VALUE abusesArnd Bergmann
Most users of IS_ERR_VALUE() in the kernel are wrong, as they pass an 'int' into a function that takes an 'unsigned long' argument. This happens to work because the type is sign-extended on 64-bit architectures before it gets converted into an unsigned type. However, anything that passes an 'unsigned short' or 'unsigned int' argument into IS_ERR_VALUE() is guaranteed to be broken, as are 8-bit integers and types that are wider than 'unsigned long'. Andrzej Hajda has already fixed a lot of the worst abusers that were causing actual bugs, but it would be nice to prevent any users that are not passing 'unsigned long' arguments. This patch changes all users of IS_ERR_VALUE() that I could find on 32-bit ARM randconfig builds and x86 allmodconfig. For the moment, this doesn't change the definition of IS_ERR_VALUE() because there are probably still architecture specific users elsewhere. Almost all the warnings I got are for files that are better off using 'if (err)' or 'if (err < 0)'. The only legitimate user I could find that we get a warning for is the (32-bit only) freescale fman driver, so I did not remove the IS_ERR_VALUE() there but changed the type to 'unsigned long'. For 9pfs, I just worked around one user whose calling conventions are so obscure that I did not dare change the behavior. I was using this definition for testing: #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \ unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO)) which ends up making all 16-bit or wider types work correctly with the most plausible interpretation of what IS_ERR_VALUE() was supposed to return according to its users, but also causes a compile-time warning for any users that do not pass an 'unsigned long' argument. I suggested this approach earlier this year, but back then we ended up deciding to just fix the users that are obviously broken. After the initial warning that caused me to get involved in the discussion (fs/gfs2/dir.c) showed up again in the mainline kernel, Linus asked me to send the whole thing again. [ Updated the 9p parts as per Al Viro - Linus ] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Andrzej Hajda <a.hajda@samsung.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.org/lkml/2016/1/7/363 Link: https://lkml.org/lkml/2016/5/27/486 Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04fs/binfmt_flat.c: make old_reloc() staticAxel Lin
old_reloc() is only used in this file, make it static. Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29new helper: read_code()Al Viro
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 <viro@zeniv.linux.org.uk>
2013-02-22new helper: file_inode(file)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28get rid of pt_regs argument of ->load_binary()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-06coredump: pass siginfo_t* to do_coredump() and below, not merely signrDenys Vlasenko
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 <vda.linux@googlemail.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: "Jonathan M. Foote" <jmfoote@cert.org> Cc: Roland McGrath <roland@hack.frob.com> Cc: Pedro Alves <palves@redhat.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-30binfmt_flat: use vm_munmap, we are missing ->mmap_sem thereAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-04-20VM: add "vm_mmap()" helper functionLinus Torvalds
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 <torvalds@linux-foundation.org>
2012-03-28Merge tag 'split-asm_system_h-for-linus-20120328' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system Pull "Disintegrate and delete asm/system.h" from David Howells: "Here are a bunch of patches to disintegrate asm/system.h into a set of separate bits to relieve the problem of circular inclusion dependencies. I've built all the working defconfigs from all the arches that I can and made sure that they don't break. The reason for these patches is that I recently encountered a circular dependency problem that came about when I produced some patches to optimise get_order() by rewriting it to use ilog2(). This uses bitops - and on the SH arch asm/bitops.h drags in asm-generic/get_order.h by a circuituous route involving asm/system.h. The main difficulty seems to be asm/system.h. It holds a number of low level bits with no/few dependencies that are commonly used (eg. memory barriers) and a number of bits with more dependencies that aren't used in many places (eg. switch_to()). These patches break asm/system.h up into the following core pieces: (1) asm/barrier.h Move memory barriers here. This already done for MIPS and Alpha. (2) asm/switch_to.h Move switch_to() and related stuff here. (3) asm/exec.h Move arch_align_stack() here. Other process execution related bits could perhaps go here from asm/processor.h. (4) asm/cmpxchg.h Move xchg() and cmpxchg() here as they're full word atomic ops and frequently used by atomic_xchg() and atomic_cmpxchg(). (5) asm/bug.h Move die() and related bits. (6) asm/auxvec.h Move AT_VECTOR_SIZE_ARCH here. Other arch headers are created as needed on a per-arch basis." Fixed up some conflicts from other header file cleanups and moving code around that has happened in the meantime, so David's testing is somewhat weakened by that. We'll find out anything that got broken and fix it.. * tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits) Delete all instances of asm/system.h Remove all #inclusions of asm/system.h Add #includes needed to permit the removal of asm/system.h Move all declarations of free_initmem() to linux/mm.h Disintegrate asm/system.h for OpenRISC Split arch_align_stack() out from asm-generic/system.h Split the switch_to() wrapper out of asm-generic/system.h Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h Create asm-generic/barrier.h Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h Disintegrate asm/system.h for Xtensa Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt] Disintegrate asm/system.h for Tile Disintegrate asm/system.h for Sparc Disintegrate asm/system.h for SH Disintegrate asm/system.h for Score Disintegrate asm/system.h for S390 Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PA-RISC Disintegrate asm/system.h for MN10300 ...
2012-03-28Remove all #inclusions of asm/system.hDavid Howells
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*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-24Merge tag 'module-for-3.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull cleanup of fs/ and lib/ users of module.h from Paul Gortmaker: "Fix up files in fs/ and lib/ dirs to only use module.h if they really need it. These are trivial in scope vs the work done previously. We now have things where any few remaining cleanups can be farmed out to arch or subsystem maintainers, and I have done so when possible. What is remaining here represents the bits that don't clearly lie within a single arch/subsystem boundary, like the fs dir and the lib dir. Some duplicate includes arising from overlapping fixes from independent subsystem maintainer submissions are also quashed." Fix up trivial conflicts due to clashes with other include file cleanups (including some due to the previous bug.h cleanup pull). * tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: lib: reduce the use of module.h wherever possible fs: reduce the use of module.h wherever possible includecheck: delete any duplicate instances of module.h
2012-03-20take removal of PF_FORKNOEXEC to flush_old_exec()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20__register_binfmt() made voidAl Viro
Just don't pass NULL to it - nobody does, anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-02-28fs: reduce the use of module.h wherever possiblePaul Gortmaker
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-05-03CRED: Fix load_flat_shared_library() to initialise bprm correctlyDavid Howells
Fix binfmt_flag's load_flat_shared_library() to initialise bprm correctly. Currently, prepare_binprm() is called with only .filename .file and .cred fields set in bprm, but the .cred_prepared and .per_clear fields at least need initialising. Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2010-06-29flat: tweak default stack alignmentMike Frysinger
The recent commit 1f0ce8b3dd667dca7 ("mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slab_def.h>") which moved the ARCH_SLAB_MINALIGN default into the global header inadvertently broke FLAT for a bunch of systems. Blackfin systems now fail on any FLAT exec with: Unable to read code+data+bss, errno 14 When your /init is a FLAT binary, obviously this can be annoying ;). This stems from the alignment usage in the FLAT loader. The behavior before was that FLAT would default to ARCH_SLAB_MINALIGN only if it was defined, and this was only defined by arches when they wanted a larger alignment value. Otherwise it'd default to pointer alignment. Arguably, this is kind of hokey that the FLAT is semi-abusing defines it shouldn't. So let's merge the two alignment requirements so the floor is never 0. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Cc: David McCullough <davidm@snapgear.com> Cc: Greg Ungerer <gerg@uclinux.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: David Howells <dhowells@redhat.com> Cc: David Woodhouse <David.Woodhouse@intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-04flat: fix unmap len in load error pathMike Frysinger
The data chunk is mmaped with 'len' which remains unchanged, so use that when unmapping in the error path rather than trying to recalculate (and incorrectly so) the value used originally. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: David McCullough <davidm@snapgear.com> Acked-by: Greg Ungerer <gerg@uclinux.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-04fs/binfmt_flat.c: split the stack & data alignmentsMike Frysinger
The stack and data have different alignment requirements, so don't force them to wear the same shoe. Increase the data alignment to match that which the elf2flt linker script has always been using: 0x20 bytes. Not only does this bring the kernel loader in line with the toolchain, but it also fixes a swath of gcc tests which try to force larger alignment values but randomly fail when the FLAT loader fails to deliver. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: David Woodhouse <David.Woodhouse@intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: David McCullough <davidm@snapgear.com> Acked-by: Greg Ungerer <gerg@uclinux.org> Cc: Paul Mundt <lethal@linux-sh.org> Tested-by: Michal Simek <monstr@monstr.eu> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jie Zhang <jie@codesourcery.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-21uclinux: error message when FLAT reloc symbol is invalid, v2Jun Sun
This patch fixes a cosmetic error in printk. Text segment and data/bss segment are allocated from two different areas. It is not meaningful to give the diff between them in the error reporting messages. Signed-off-by: Jun Sun <jsun@junsun.net> Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2010-03-06fs: use rlimit helpersJiri Slaby
Make sure compiler won't do weird things with limits. E.g. fetching them twice may return 2 different values after writable limits are implemented. I.e. either use rlimit helpers added in commit 3e10e716abf3 ("resource: add helpers for fetching rlimits") or ACCESS_ONCE if not applicable. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-29Split 'flush_old_exec' into two functionsLinus Torvalds
'flush_old_exec()' is the point of no return when doing an execve(), and it is pretty badly misnamed. It doesn't just flush the old executable environment, it also starts up the new one. Which is very inconvenient for things like setting up the new personality, because we want the new personality to affect the starting of the new environment, but at the same time we do _not_ want the new personality to take effect if flushing the old one fails. As a result, the x86-64 '32-bit' personality is actually done using this insane "I'm going to change the ABI, but I haven't done it yet" bit (TIF_ABI_PENDING), with SET_PERSONALITY() not actually setting the personality, but just the "pending" bit, so that "flush_thread()" can do the actual personality magic. This patch in no way changes any of that insanity, but it does split the 'flush_old_exec()' function up into a preparatory part that can fail (still called flush_old_exec()), and a new part that will actually set up the new exec environment (setup_new_exec()). All callers are changed to trivially comply with the new world order. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-17mm: introduce coredump parameter structureMasami Hiramatsu
Introduce coredump parameter data structure (struct coredump_params) to simplify binfmt->core_dump() arguments. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Suggested-by: Ingo Molnar <mingo@elte.hu> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24flat: use IS_ERR_VALUE() helper macroMike Frysinger
There is a common macro now for testing mixed pointer/errno values, so use that rather than handling the casts ourself. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: David McCullough <david_mccullough@securecomputing.com> Acked-by: Greg Ungerer <gerg@uclinux.org> Cc: David Howells <dhowells@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-07flat: fix uninitialized ptr with shared libsLinus Torvalds
The new credentials code broke load_flat_shared_library() as it now uses an uninitialized cred pointer. Reported-by: Bernd Schmidt <bernds_cb1@t-online.de> Tested-by: Bernd Schmidt <bernds_cb1@t-online.de> Cc: Mike Frysinger <vapier@gentoo.org> Cc: David Howells <dhowells@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-29flat: fix data sections alignmentOskar Schirmer
The flat loader uses an architecture's flat_stack_align() to align the stack but assumes word-alignment is enough for the data sections. However, on the Xtensa S6000 we have registers up to 128bit width which can be used from userspace and therefor need userspace stack and data-section alignment of at least this size. This patch drops flat_stack_align() and uses the same alignment that is required for slab caches, ARCH_SLAB_MINALIGN, or wordsize if it's not defined by the architecture. It also fixes m32r which was obviously kaput, aligning an uninitialized stack entry instead of the stack pointer. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Oskar Schirmer <os@emlix.com> Cc: David Howells <dhowells@redhat.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Bryan Wu <cooloney@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Paul Mundt <lethal@linux-sh.org> Cc: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Johannes Weiner <jw@emlix.com> Acked-by: Mike Frysinger <vapier.adi@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08FLAT: Don't attempt to expand the userspace stack to fill the space allocatedDavid Howells
Stop the FLAT binfmt from attempting to expand the userspace stack and brk segments to fill the space actually allocated for it. The space allocated may be rounded up by mmap(), and may be wasted. However, finding out how much space we actually obtained uses the contentious kobjsize() function which we'd like to get rid of as it doesn't necessarily work for all slab allocators. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Mike Frysinger <vapier.adi@gmail.com> Acked-by: Paul Mundt <lethal@linux-sh.org>
2008-11-14CRED: Make execve() take advantage of copy-on-write credentialsDavid Howells
Make execve() take advantage of copy-on-write credentials, allowing it to set up the credentials in advance, and then commit the whole lot after the point of no return. This patch and the preceding patches have been tested with the LTP SELinux testsuite. This patch makes several logical sets of alteration: (1) execve(). The credential bits from struct linux_binprm are, for the most part, replaced with a single credentials pointer (bprm->cred). This means that all the creds can be calculated in advance and then applied at the point of no return with no possibility of failure. I would like to replace bprm->cap_effective with: cap_isclear(bprm->cap_effective) but this seems impossible due to special behaviour for processes of pid 1 (they always retain their parent's capability masks where normally they'd be changed - see cap_bprm_set_creds()). The following sequence of events now happens: (a) At the start of do_execve, the current task's cred_exec_mutex is locked to prevent PTRACE_ATTACH from obsoleting the calculation of creds that we make. (a) prepare_exec_creds() is then called to make a copy of the current task's credentials and prepare it. This copy is then assigned to bprm->cred. This renders security_bprm_alloc() and security_bprm_free() unnecessary, and so they've been removed. (b) The determination of unsafe execution is now performed immediately after (a) rather than later on in the code. The result is stored in bprm->unsafe for future reference. (c) prepare_binprm() is called, possibly multiple times. (i) This applies the result of set[ug]id binaries to the new creds attached to bprm->cred. Personality bit clearance is recorded, but now deferred on the basis that the exec procedure may yet fail. (ii) This then calls the new security_bprm_set_creds(). This should calculate the new LSM and capability credentials into *bprm->cred. This folds together security_bprm_set() and parts of security_bprm_apply_creds() (these two have been removed). Anything that might fail must be done at this point. (iii) bprm->cred_prepared is set to 1. bprm->cred_prepared is 0 on the first pass of the security calculations, and 1 on all subsequent passes. This allows SELinux in (ii) to base its calculations only on the initial script and not on the interpreter. (d) flush_old_exec() is called to commit the task to execution. This performs the following steps with regard to credentials: (i) Clear pdeath_signal and set dumpable on certain circumstances that may not be covered by commit_creds(). (ii) Clear any bits in current->personality that were deferred from (c.i). (e) install_exec_creds() [compute_creds() as was] is called to install the new credentials. This performs the following steps with regard to credentials: (i) Calls security_bprm_committing_creds() to apply any security requirements, such as flushing unauthorised files in SELinux, that must be done before the credentials are changed. This is made up of bits of security_bprm_apply_creds() and security_bprm_post_apply_creds(), both of which have been removed. This function is not allowed to fail; anything that might fail must have been done in (c.ii). (ii) Calls commit_creds() to apply the new credentials in a single assignment (more or less). Possibly pdeath_signal and dumpable should be part of struct creds. (iii) Unlocks the task's cred_replace_mutex, thus allowing PTRACE_ATTACH to take place. (iv) Clears The bprm->cred pointer as the credentials it was holding are now immutable. (v) Calls security_bprm_committed_creds() to apply any security alterations that must be done after the creds have been changed. SELinux uses this to flush signals and signal handlers. (f) If an error occurs before (d.i), bprm_free() will call abort_creds() to destroy the proposed new credentials and will then unlock cred_replace_mutex. No changes to the credentials will have been made. (2) LSM interface. A number of functions have been changed, added or removed: (*) security_bprm_alloc(), ->bprm_alloc_security() (*) security_bprm_free(), ->bprm_free_security() Removed in favour of preparing new credentials and modifying those. (*) security_bprm_apply_creds(), ->bprm_apply_creds() (*) security_bprm_post_apply_creds(), ->bprm_post_apply_creds() Removed; split between security_bprm_set_creds(), security_bprm_committing_creds() and security_bprm_committed_creds(). (*) security_bprm_set(), ->bprm_set_security() Removed; folded into security_bprm_set_creds(). (*) security_bprm_set_creds(), ->bprm_set_creds() New. The new credentials in bprm->creds should be checked and set up as appropriate. bprm->cred_prepared is 0 on the first call, 1 on the second and subsequent calls. (*) security_bprm_committing_creds(), ->bprm_committing_creds() (*) security_bprm_committed_creds(), ->bprm_committed_creds() New. Apply the security effects of the new credentials. This includes closing unauthorised files in SELinux. This function may not fail. When the former is called, the creds haven't yet been applied to the process; when the latter is called, they have. The former may access bprm->cred, the latter may not. (3) SELinux. SELinux has a number of changes, in addition to those to support the LSM interface changes mentioned above: (a) The bprm_security_struct struct has been removed in favour of using the credentials-under-construction approach. (c) flush_unauthorized_files() now takes a cred pointer and passes it on to inode_has_perm(), file_has_perm() and dentry_open(). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-10-16uclinux: fix gzip header parsing in binfmt_flat.cVolodymyr G. Lukiianyk
There are off-by-one errors in decompress_exec() when calculating the length of optional "original file name" and "comment" fields: the "ret" index is not incremented when terminating '\0' character is reached. The check of the buffer overflow (after an "extra-field" length was taken into account) is also fixed. I've encountered this off-by-one error when tried to reuse gzip-header-parsing part of the decompress_exec() function. There was an "original file name" field in the payload (with miscalculated length) and zlib_inflate() returned Z_DATA_ERROR. But after the fix similar to this one all worked fine. Signed-off-by: Volodymyr G Lukiianyk <volodymyrgl@gmail.com> Acked-by: Greg Ungerer <gerg@snapgear.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-11binfmt_flat: Stub in a FLAT_PLAT_INIT().Takashi YOSHII
This provides a FLAT_PLAT_INIT() arch hook for platforms that need to set up specific register state prior to calling in to the process, as per ELF_PLAT_INIT(). Signed-off-by: Takashi YOSHII <yoshii.takashi@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-07-26tracehook: execRoland McGrath
This moves all the ptrace hooks related to exec into tracehook.h inlines. This also lifts the calls for tracing out of the binfmt load_binary hooks into search_binary_handler() after it calls into the binfmt module. This change has no effect, since all the binfmt modules' load_binary functions did the call at the end on success, and now search_binary_handler() does it immediately after return if successful. We consolidate the repeated code, and binfmt modules no longer need to import ptrace_notify(). Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06nommu: fix ksize() abusePekka Enberg
The nommu binfmt code uses ksize() for pointers returned from do_mmap() which is wrong. This converts the call-sites to use the nommu specific kobjsize() function which works as expected. Cc: Christoph Lameter <clameter@sgi.com> Cc: Matt Mackall <mpm@selenic.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29procfs task exe symlinkMatt Helsley
The kernel implements readlink of /proc/pid/exe by getting the file from the first executable VMA. Then the path to the file is reconstructed and reported as the result. Because of the VMA walk the code is slightly different on nommu systems. This patch avoids separate /proc/pid/exe code on nommu systems. Instead of walking the VMAs to find the first executable file-backed VMA we store a reference to the exec'd file in the mm_struct. That reference would prevent the filesystem holding the executable file from being unmounted even after unmapping the VMAs. So we track the number of VM_EXECUTABLE VMAs and drop the new reference when the last one is unmapped. This avoids pinning the mounted filesystem. [akpm@linux-foundation.org: improve comments] [yamamoto@valinux.co.jp: fix dup_mmap] Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: David Howells <dhowells@redhat.com> Cc:"Eric W. Biederman" <ebiederm@xmission.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29make BINFMT_FLAT a boolAdrian Bunk
I have not yet seen anyone saying he has a reasonable use case for using BINFMT_FLAT modular on his embedded device. Considering that fs/binfmt_flat.c even lacks a MODULE_LICENSE() I really doubt there is any, and this patch therefore makes BINFMT_FLAT a bool. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Bryan Wu <cooloney.lkml@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14FLAT binaries: drop BINFMT_FLAT bad header magic warningMike Frysinger
The warning issued by fs/binfmt_flat.c when the format handler is given a non-FLAT and non-script executable is annoying to say the least when working with FDPIC ELF objects. If you build a kernel that supports both FLAT and FDPIC ELFs on no-mmu, every time you execute an FDPIC ELF, the kernel spits out this message. While I understand a lot of newcomers to the no-mmu world screw up generation of FLAT binaries, this warning is not usable for systems that support more than just FLAT. Signed-off-by: Jie Zhang <jie.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Cc: Bernd Schmidt <bernds_cb1@t-online.de> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08aout: remove unnecessary inclusions of {asm, linux}/a.out.hDavid Howells
Remove now unnecessary inclusions of {asm,linux}/a.out.h. [akpm@linux-foundation.org: fix alpha build] Signed-off-by: David Howells <dhowells@redhat.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17binfmt_flat: warning fixesAndrew Morton
Fix this lot: fs/binfmt_flat.c: In function `decompress_exec': fs/binfmt_flat.c:293: warning: label `out' defined but not used fs/binfmt_flat.c: In function `load_flat_file': fs/binfmt_flat.c:462: warning: unsigned int format, long int arg (arg 3) fs/binfmt_flat.c:462: warning: unsigned int format, long int arg (arg 4) fs/binfmt_flat.c:518: warning: comparison of distinct pointer types lacks a cast fs/binfmt_flat.c:549: warning: passing arg 1 of `ksize' makes pointer from integer without a cast fs/binfmt_flat.c:601: warning: passing arg 1 of `ksize' makes pointer from integer without a cast fs/binfmt_flat.c: In function `load_flat_binary': fs/binfmt_flat.c:116: warning: 'dummy' might be used uninitialized in this function Acked-by: Greg Ungerer <gerg@uclinux.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17core_pattern: ignore RLIMIT_CORE if core_pattern is a pipeNeil Horman
For some time /proc/sys/kernel/core_pattern has been able to set its output destination as a pipe, allowing a user space helper to receive and intellegently process a core. This infrastructure however has some shortcommings which can be enhanced. Specifically: 1) The coredump code in the kernel should ignore RLIMIT_CORE limitation when core_pattern is a pipe, since file system resources are not being consumed in this case, unless the user application wishes to save the core, at which point the app is restricted by usual file system limits and restrictions. 2) The core_pattern code should be able to parse and pass options to the user space helper as an argv array. The real core limit of the uid of the crashing proces should also be passable to the user space helper (since it is overridden to zero when called). 3) Some miscellaneous bugs need to be cleaned up (specifically the recognition of a recursive core dump, should the user mode helper itself crash. Also, the core dump code in the kernel should not wait for the user mode helper to exit, since the same context is responsible for writing to the pipe, and a read of the pipe by the user mode helper will result in a deadlock. This patch: Remove the check of RLIMIT_CORE if core_pattern is a pipe. In the event that core_pattern is a pipe, the entire core will be fed to the user mode helper. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Cc: <martin.pitt@ubuntu.com> Cc: <wwoods@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-03binfmt_flat: checkpatch fixing minimum support for the blackfin relocationsAndrew Morton
Cc: Bernd Schmidt <bernd.schmidt@analog.com> Cc: David McCullough <davidm@snapgear.com> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Miles Bader <miles.bader@necel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Bryan Wu <bryan.wu@analog.com>