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2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-10Merge tag 'libnvdimm-for-4.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "Outside of the new ACPI-NFIT hot-add support this pull request is more notable for what it does not contain, than what it does. There were a handful of development topics this cycle, dax get_user_pages, dax fsync, and raw block dax, that need more more iteration and will wait for 4.5. The patches to make devm and the pmem driver NUMA aware have been in -next for several weeks. The hot-add support has not, but is contained to the NFIT driver and is passing unit tests. The coredump support is straightforward and was looked over by Jeff. All of it has received a 0day build success notification across 107 configs. Summary: - Add support for the ACPI 6.0 NFIT hot add mechanism to process updates of the NFIT at runtime. - Teach the coredump implementation how to filter out DAX mappings. - Introduce NUMA hints for allocations made by the pmem driver, and as a side effect all devm allocations now hint their NUMA node by default" * tag 'libnvdimm-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: coredump: add DAX filtering for FDPIC ELF coredumps coredump: add DAX filtering for ELF coredumps acpi: nfit: Add support for hot-add nfit: in acpi_nfit_init, break on a 0-length table pmem, memremap: convert to numa aware allocations devm_memremap_pages: use numa_mem_id devm: make allocations numa aware by default devm_memremap: convert to return ERR_PTR devm_memunmap: use devres_release() pmem: kill memremap_pmem() x86, mm: quiet arch_add_memory()
2015-11-09Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge third patch-bomb from Andrew Morton: "We're pretty much done over here - I'm still waiting for a nouveau merge so I can cleanly finish up Christoph's dma-mapping rework. - bunch of small misc stuff - fold abs64() into abs(), remove abs64() - new_valid_dev() cleanups - binfmt_elf_fdpic feature work" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (24 commits) fs/binfmt_elf_fdpic.c: provide NOMMU loader for regular ELF binaries fs/stat.c: remove unnecessary new_valid_dev() check fs/reiserfs/namei.c: remove unnecessary new_valid_dev() check fs/nilfs2/namei.c: remove unnecessary new_valid_dev() check fs/ncpfs/dir.c: remove unnecessary new_valid_dev() check fs/jfs: remove unnecessary new_valid_dev() checks fs/hpfs/namei.c: remove unnecessary new_valid_dev() check fs/f2fs/namei.c: remove unnecessary new_valid_dev() check fs/ext2/namei.c: remove unnecessary new_valid_dev() check fs/exofs/namei.c: remove unnecessary new_valid_dev() check fs/btrfs/inode.c: remove unnecessary new_valid_dev() check fs/9p: remove unnecessary new_valid_dev() checks include/linux/kdev_t.h: old/new_valid_dev() can return bool include/linux/kdev_t.h: remove unused huge_valid_dev() kmap_atomic_to_page() has no users, remove it drivers/scsi/cxgbi: fix build with EXTRA_CFLAGS dma: remove external references to dma_supported Documentation/sysctl/vm.txt: fix misleading code reference of overcommit_memory remove abs64() kernel.h: make abs() work with 64-bit types ...
2015-11-09fs/binfmt_elf_fdpic.c: provide NOMMU loader for regular ELF binariesRich Felker
The ELF binary loader in binfmt_elf.c requires an MMU, making it impossible to use regular ELF binaries on NOMMU archs. However, the FDPIC ELF loader in binfmt_elf_fdpic.c is fully capable as a loader for plain ELF, which requires constant displacements between LOAD segments, since it already supports FDPIC ELF files flagged as needing constant displacement. This patch adjusts the FDPIC ELF loader to accept non-FDPIC ELF files on NOMMU archs. They are treated identically to FDPIC ELF files with the constant-displacement flag bit set, except for personality, which must match the ABI of the program being loaded; the PER_LINUX_FDPIC personality controls how the kernel interprets function pointers passed to sigaction. Files that do not set a stack size requirement explicitly are given a default stack size (matching the amount of committed stack the normal ELF loader for MMU archs would give them) rather than being rejected; this is necessary because plain ELF files generally do not declare stack requirements in theit program headers. Only ET_DYN (PIE) format ELF files are supported, since loading at a fixed virtual address is not possible on NOMMU. This patch was developed and tested on J2 (SH2-compatible) but should be usable immediately on all archs where binfmt_elf_fdpic is available. Moreover, by providing dummy definitions of the elf_check_fdpic() and elf_check_const_displacement() macros for archs which lack an FDPIC ABI, it should be possible to enable building of binfmt_elf_fdpic on all other NOMMU archs and thereby give them ELF binary support, but I have not yet tested this. The motivation for using binfmt_elf_fdpic.c rather than adapting binfmt_elf.c to NOMMU is that the former already has all the necessary code to work properly on NOMMU and has already received widespread real-world use and testing. I hope this is not controversial. I'm not really happy with having to unset the FDPIC_FUNCPTRS personality bit when loading non-FDPIC ELF. This bit should really reset automatically on execve, since otherwise, executing non-ELF binaries (e.g. bFLT) from an FDPIC process will leave the personality in the wrong state and severely break signal handling. But that's a separate, existing bug and I don't know the right place to fix it. Signed-off-by: Rich Felker <dalias@libc.org> Acked-by: Greg Ungerer <gerg@uclinux.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Matt Mackall <mpm@selenic.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Oleg Endo <oleg.endo@t-online.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-09coredump: add DAX filtering for FDPIC ELF coredumpsRoss Zwisler
Add explicit filtering for DAX mappings to FDPIC ELF coredump. This is useful because DAX mappings have the potential to be very large. This patch has only been compile tested. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-10-26fs/binfmt_elf_fdpic.c: fix brk area overlap with stack on NOMMURich Felker
On NOMMU archs, the FDPIC ELF loader sets up the usable brk range to overlap with all but the last PAGE_SIZE bytes of the stack. This leads to catastrophic memory reuse/corruption if brk is used. Fix by setting the brk area to zero size to disable its use. Signed-off-by: Rich Felker <dalias@libc.org> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2014-10-09handle suicide on late failure exits in execve() in search_binary_handler()Al Viro
... 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 <viro@zeniv.linux.org.uk>
2013-11-09elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo)Al Viro
we can't get to do_coredump() if that condition isn't satisfied... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09new helper: dump_align()Al Viro
dump_skip to given alignment... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09dump_skip(): dump_seek() replacement taking coredump_paramsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09convert the rest of binfmt_elf_fdpic to dump_emit()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09switch elf_core_write_extra_data() to dump_emit()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09switch elf_core_write_extra_phdrs() to dump_emit()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24file->f_op is never NULL...Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-02Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc update from Benjamin Herrenschmidt: "The main highlights this time around are: - A pile of addition POWER8 bits and nits, such as updated performance counter support (Michael Ellerman), new branch history buffer support (Anshuman Khandual), base support for the new PCI host bridge when not using the hypervisor (Gavin Shan) and other random related bits and fixes from various contributors. - Some rework of our page table format by Aneesh Kumar which fixes a thing or two and paves the way for THP support. THP itself will not make it this time around however. - More Freescale updates, including Altivec support on the new e6500 cores, new PCI controller support, and a pile of new boards support and updates. - The usual batch of trivial cleanups & fixes" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits) powerpc: Fix build error for book3e powerpc: Context switch the new EBB SPRs powerpc: Turn on the EBB H/FSCR bits powerpc: Replace CPU_FTR_BCTAR with CPU_FTR_ARCH_207S powerpc: Setup BHRB instructions facility in HFSCR for POWER8 powerpc: Fix interrupt range check on debug exception powerpc: Update tlbie/tlbiel as per ISA doc powerpc: Print page size info during boot powerpc: print both base and actual page size on hash failure powerpc: Fix hpte_decode to use the correct decoding for page sizes powerpc: Decode the pte-lp-encoding bits correctly. powerpc: Use encode avpn where we need only avpn values powerpc: Reduce PTE table memory wastage powerpc: Move the pte free routines from common header powerpc: Reduce the PTE_INDEX_SIZE powerpc: Switch 16GB and 16MB explicit hugepages to a different page table format powerpc: New hugepage directory format powerpc: Don't truncate pgd_index wrongly powerpc: Don't hard code the size of pte page powerpc: Save DAR and DSISR in pt_regs on MCE ...
2013-05-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 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 ...
2013-04-30coredump: factor out the setting of PF_DUMPCOREOleg Nesterov
Cleanup. Every linux_binfmt->core_dump() sets PF_DUMPCORE, move this into zap_threads() called by do_coredump(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Mandeep Singh Baines <msb@chromium.org> Cc: Neil Horman <nhorman@redhat.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> 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>
2013-04-26powerpc: Add HWCAP2 aux entryMichael Neuling
We are currently out of free bits in AT_HWCAP. With POWER8, we have several hardware features that we need to advertise. Tested on POWER and x86. Signed-off-by: Michael Neuling <michael@neuling.org> Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-26Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile (part one) from Al Viro: "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent locking violations, etc. The most visible changes here are death of FS_REVAL_DOT (replaced with "has ->d_weak_revalidate()") and a new helper getting from struct file to inode. Some bits of preparation to xattr method interface changes. Misc patches by various people sent this cycle *and* ocfs2 fixes from several cycles ago that should've been upstream right then. PS: the next vfs pile will be xattr stuff." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) saner proc_get_inode() calling conventions proc: avoid extra pde_put() in proc_fill_super() fs: change return values from -EACCES to -EPERM fs/exec.c: make bprm_mm_init() static ocfs2/dlm: use GFP_ATOMIC inside a spin_lock ocfs2: fix possible use-after-free with AIO ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero target: writev() on single-element vector is pointless export kernel_write(), convert open-coded instances fs: encode_fh: return FILEID_INVALID if invalid fid_type kill f_vfsmnt vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op nfsd: handle vfs_getattr errors in acl protocol switch vfs_getattr() to struct path default SET_PERSONALITY() in linux/elf.h ceph: prepopulate inodes only when request is aborted d_hash_and_lookup(): export, switch open-coded instances 9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate() 9p: split dropping the acls from v9fs_set_create_acl() ...
2013-02-22new helper: file_inode(file)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-01-27cputime: Use accessors to read task cputime statsFrederic Weisbecker
This is in preparation for the full dynticks feature. While remotely reading the cputime of a task running in a full dynticks CPU, we'll need to do some extra-computation. This way we can account the time it spent tickless in userspace since its last cputime snapshot. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-11-28get rid of pt_regs argument of ->load_binary()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull generic execve() changes from Al Viro: "This introduces the generic kernel_thread() and kernel_execve() functions, and switches x86, arm, alpha, um and s390 over to them." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits) s390: convert to generic kernel_execve() s390: switch to generic kernel_thread() s390: fold kernel_thread_helper() into ret_from_fork() s390: fold execve_tail() into start_thread(), convert to generic sys_execve() um: switch to generic kernel_thread() x86, um/x86: switch to generic sys_execve and kernel_execve x86: split ret_from_fork alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve() alpha: switch to generic kernel_thread() alpha: switch to generic sys_execve() arm: get rid of execve wrapper, switch to generic execve() implementation arm: optimized current_pt_regs() arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve() arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk] generic sys_execve() generic kernel_execve() new helper: current_pt_regs() preparation for generic kernel_thread() um: kill thread->forking um: let signal_delivered() do SIGTRAP on singlestepping into handler ...
2012-10-09mm: kill vma flag VM_RESERVED and mm->reserved_vm counterKonstantin Khlebnikov
A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA, currently it lost original meaning but still has some effects: | effect | alternative flags -+------------------------+--------------------------------------------- 1| account as reserved_vm | VM_IO 2| skip in core dump | VM_IO, VM_DONTDUMP 3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP 4| do not mlock | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP This patch removes reserved_vm counter from mm_struct. Seems like nobody cares about it, it does not exported into userspace directly, it only reduces total_vm showed in proc. Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP. remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP. remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP. [akpm@linux-foundation.org: drivers/vfio/pci/vfio_pci.c fixup] Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Eric Paris <eparis@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Venkatesh Pallipadi <venki@google.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
2012-09-20the only place that needs to include asm/exec.h is linux/binfmts.hAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace enhancements from Eric Biederman: "This is a course correction for the user namespace, so that we can reach an inexpensive, maintainable, and reasonably complete implementation. Highlights: - Config guards make it impossible to enable the user namespace and code that has not been converted to be user namespace safe. - Use of the new kuid_t type ensures the if you somehow get past the config guards the kernel will encounter type errors if you enable user namespaces and attempt to compile in code whose permission checks have not been updated to be user namespace safe. - All uids from child user namespaces are mapped into the initial user namespace before they are processed. Removing the need to add an additional check to see if the user namespace of the compared uids remains the same. - With the user namespaces compiled out the performance is as good or better than it is today. - For most operations absolutely nothing changes performance or operationally with the user namespace enabled. - The worst case performance I could come up with was timing 1 billion cache cold stat operations with the user namespace code enabled. This went from 156s to 164s on my laptop (or 156ns to 164ns per stat operation). - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value. Most uid/gid setting system calls treat these value specially anyway so attempting to use -1 as a uid would likely cause entertaining failures in userspace. - If setuid is called with a uid that can not be mapped setuid fails. I have looked at sendmail, login, ssh and every other program I could think of that would call setuid and they all check for and handle the case where setuid fails. - If stat or a similar system call is called from a context in which we can not map a uid we lie and return overflowuid. The LFS experience suggests not lying and returning an error code might be better, but the historical precedent with uids is different and I can not think of anything that would break by lying about a uid we can't map. - Capabilities are localized to the current user namespace making it safe to give the initial user in a user namespace all capabilities. My git tree covers all of the modifications needed to convert the core kernel and enough changes to make a system bootable to runlevel 1." Fix up trivial conflicts due to nearby independent changes in fs/stat.c * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits) userns: Silence silly gcc warning. cred: use correct cred accessor with regards to rcu read lock userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq userns: Convert cgroup permission checks to use uid_eq userns: Convert tmpfs to use kuid and kgid where appropriate userns: Convert sysfs to use kgid/kuid where appropriate userns: Convert sysctl permission checks to use kuid and kgids. userns: Convert proc to use kuid/kgid where appropriate userns: Convert ext4 to user kuid/kgid where appropriate userns: Convert ext3 to use kuid/kgid where appropriate userns: Convert ext2 to use kuid/kgid where appropriate. userns: Convert devpts to use kuid/kgid where appropriate userns: Convert binary formats to use kuid/kgid where appropriate userns: Add negative depends on entries to avoid building code that is userns unsafe userns: signal remove unnecessary map_cred_ns userns: Teach inode_capable to understand inodes whose uids map to other namespaces. userns: Fail exec for suid and sgid binaries with ids outside our user namespace. userns: Convert stat to return values mapped from kuids and kgids userns: Convert user specfied uids and gids in chown into kuids and kgid userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs ...
2012-05-15userns: Convert binary formats to use kuid/kgid where appropriateEric W. Biederman
Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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>
2012-03-28Add #includes needed to permit the removal of asm/system.hDavid Howells
asm/system.h is a cause of circular dependency problems because it contains commonly used primitive stuff like barrier definitions and uncommonly used stuff like switch_to() that might require MMU definitions. asm/system.h has been disintegrated by this point on all arches into the following common segments: (1) asm/barrier.h Moved memory barrier definitions here. (2) asm/cmpxchg.h Moved xchg() and cmpxchg() here. #included in asm/atomic.h. (3) asm/bug.h Moved die() and similar here. (4) asm/exec.h Moved arch_align_stack() here. (5) asm/elf.h Moved AT_VECTOR_SIZE_ARCH here. (6) asm/switch_to.h Moved switch_to() here. Signed-off-by: David Howells <dhowells@redhat.com>
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>
2011-07-20consolidate BINPRM_FLAGS_ENFORCE_NONDUMP handlingAl Viro
new helper: would_dump(bprm, file). Checks if we are allowed to read the file and if we are not - sets ENFORCE_NODUMP. Exported, used in places that previously open-coded the same logics. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-06FDPIC: Fix memory leakDavidlohr Bueso
The shdr4extnum variable isn't being freed in the cleanup process of elf_fdpic_core_dump(). Signed-off-by: Davidlohr Bueso <dave@gnu.org> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-01binfmt_elf_fdpic: Fix clear_user() error handlingTakuya Yoshikawa
clear_user() returns the number of bytes that could not be copied rather than an error code. So we should return -EFAULT rather than directly returning the results. Without this patch, positive values may be returned to elf_fdpic_map_file() and the following error handlings do not function as expected. 1. ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); if (ret < 0) return ret; 2. ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); if (ret < 0) return ret; Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mike Frysinger <vapier@gentoo.org> CC: Alexander Viro <viro@zeniv.linux.org.uk> CC: Andrew Morton <akpm@linux-foundation.org> CC: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com> CC: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-27Remove redundant check for CONFIG_MMUChristoph Egger
The checks for CONFIG_MMU at this location are duplicated as all the code is located inside a #ifndef CONFIG_MMU block. So the first conditional block will always be included while the second never will. Signed-off-by: Christoph Egger <siccegge@stud.informatik.uni-erlangen.de> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24FDPIC: For-loop in elf_core_vma_data_size() is incorrectDavid Howells
Fix an incorrect for-loop in elf_core_vma_data_size(). The advance-pointer statement lacks an assignment: CC fs/binfmt_elf_fdpic.o fs/binfmt_elf_fdpic.c: In function 'elf_core_vma_data_size': fs/binfmt_elf_fdpic.c:1593: warning: statement with no effect Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-08Merge branch 'for-next' into for-linusJiri Kosina
Conflicts: Documentation/filesystems/proc.txt arch/arm/mach-u300/include/mach/debug-macro.S drivers/net/qlge/qlge_ethtool.c drivers/net/qlge/qlge_main.c drivers/net/typhoon.c
2010-03-06coredump: pass mm->flags as a coredump parameter for consistencyMasami Hiramatsu
Pass mm->flags as a coredump parameter for consistency. --- 1787 if (mm->core_state || !get_dumpable(mm)) { <- (1) 1788 up_write(&mm->mmap_sem); 1789 put_cred(cred); 1790 goto fail; 1791 } 1792 [...] 1798 if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ <-(2) 1799 flag = O_EXCL; /* Stop rewrite attacks */ 1800 cred->fsuid = 0; /* Dump root private */ 1801 } --- Since dumpable bits are not protected by lock, there is a chance to change these bits between (1) and (2). To solve this issue, this patch copies mm->flags to coredump_params.mm_flags at the beginning of do_coredump() and uses it instead of get_dumpable() while dumping core. This copy is also passed to binfmt->core_dump, since elf*_core_dump() uses dump_filter bits in mm->flags. [akpm@linux-foundation.org: fix merge] Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Reviewed-by: 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>
2010-03-06elf coredump: add extended numbering supportDaisuke HATAYAMA
The current ELF dumper implementation can produce broken corefiles if program headers exceed 65535. This number is determined by the number of vmas which the process have. In particular, some extreme programs may use more than 65535 vmas. (If you google max_map_count, you can find some users facing this problem.) This kind of program never be able to generate correct coredumps. This patch implements ``extended numbering'' that uses sh_info field of the first section header instead of e_phnum field in order to represent upto 4294967295 vmas. This is supported by AMD64-ABI(http://www.x86-64.org/documentation.html) and Solaris(http://docs.sun.com/app/docs/doc/817-1984/). Of course, we are preparing patches for gdb and binutils. Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06elf coredump: make offset calculation process and writing process explicitDaisuke HATAYAMA
By the next patch, elf_core_dump() and elf_fdpic_core_dump() will support extended numbering and so will produce the corefiles with section header table in a special case. The problem is the process of writing a file header offset of the section header table into e_shoff field of the ELF header. ELF header is positioned at the beginning of the corefile, while section header at the end. So, we need to take which of the following ways: 1. Seek backward to retry writing operation for ELF header after writing process for a whole part 2. Make offset calculation process and writing process totally sequential The clause 1. is not always possible: one cannot assume that file system supports seek function. Consider the no_llseek case. Therefore, this patch adopts the clause 2. Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06elf coredump: replace ELF_CORE_EXTRA_* macros by functionsDaisuke HATAYAMA
elf_core_dump() and elf_fdpic_core_dump() use #ifdef and the corresponding macro for hiding _multiline_ logics in functions. This patch removes #ifdef and replaces ELF_CORE_EXTRA_* by corresponding functions. For architectures not implemeonting ELF_CORE_EXTRA_*, we use weak functions in order to reduce a range of modification. This cleanup is for my next patches, but I think this cleanup itself is worth doing regardless of my firnal purpose. Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06coredump: move dump_write() and dump_seek() into a header fileDaisuke HATAYAMA
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 <d.hatayama@jp.fujitsu.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06coredump: unify dump_seek() implementations for each binfmt_*.cDaisuke HATAYAMA
The current ELF dumper can produce broken corefiles if program headers exceed 65535. In particular, the program in 64-bit environment often demands more than 65535 mmaps. If you google max_map_count, then you can find many users facing this problem. Solaris has already dealt with this issue, and other OSes have also adopted the same method as in Solaris. Currently, Sun's document and AMD 64 ABI include the description for the extension, where they call the extension Extended Numbering. See Reference for further information. I believe that linux kernel should adopt the same way as they did, so I've written this patch. I am also preparing for patches of GDB and binutils. How to fix ========== In new dumping process, there are two cases according to weather or not the number of program headers is equal to or more than 65535. - if less than 65535, the produced corefile format is exactly the same as the ordinary one. - if equal to or more than 65535, then e_phnum field is set to newly introduced constant PN_XNUM(0xffff) and the actual number of program headers is set to sh_info field of the section header at index 0. Compatibility Concern ===================== * As already mentioned in Summary, Sun and AMD64 has already adopted this. See Reference. * There are four combinations according to whether kernel and userland tools are respectively modified or not. The next table summarizes shortly for each combination. --------------------------------------------- Original Kernel | Modified Kernel --------------------------------------------- < 65535 | >= 65535 | < 65535 | >= 65535 ------------------------------------------------------------- Original Tools | OK | broken | OK | broken (#) ------------------------------------------------------------- Modified Tools | OK | broken | OK | OK ------------------------------------------------------------- Note that there is no case that `OK' changes to `broken'. (#) Although this case remains broken, O-M behaves better than O-O. That is, while in O-O case e_phnum field would be extremely small due to integer overflow, in O-M case it is guaranteed to be at least 65535 by being set to PN_XNUM(0xFFFF), much closer to the actual correct value than the O-O case. Test Program ============ Here is a test program mkmmaps.c that is useful to produce the corefile with many mmaps. To use this, please take the following steps: $ ulimit -c unlimited $ sysctl vm.max_map_count=70000 # default 65530 is too small $ sysctl fs.file-max=70000 $ mkmmaps 65535 Then, the program will abort and a corefile will be generated. If failed, there are two cases according to the error message displayed. * ``out of memory'' means vm.max_map_count is still smaller * ``too many open files'' means fs.file-max is still smaller So, please change it to a larger value, and then retry it. mkmmaps.c == #include <stdio.h> #include <stdlib.h> #include <sys/mman.h> #include <fcntl.h> #include <unistd.h> int main(int argc, char **argv) { int maps_num; if (argc < 2) { fprintf(stderr, "mkmmaps [number of maps to be created]\n"); exit(1); } if (sscanf(argv[1], "%d", &maps_num) == EOF) { perror("sscanf"); exit(2); } if (maps_num < 0) { fprintf(stderr, "%d is invalid\n", maps_num); exit(3); } for (; maps_num > 0; --maps_num) { if (MAP_FAILED == mmap((void *)NULL, (size_t) 1, PROT_READ, MAP_SHARED | MAP_ANONYMOUS, (int) -1, (off_t) NULL)) { perror("mmap"); exit(4); } } abort(); { char buffer[128]; sprintf(buffer, "wc -l /proc/%u/maps", getpid()); system(buffer); } return 0; } Tested on i386, ia64 and um/sys-i386. Built on sh4 (which covers fs/binfmt_elf_fdpic.c) References ========== - Sun microsystems: Linker and Libraries. Part No: 817-1984-17, September 2008. URL: http://docs.sun.com/app/docs/doc/817-1984 - System V ABI AMD64 Architecture Processor Supplement Draft Version 0.99., May 11, 2009. URL: http://www.x86-64.org/ This patch: There are three different definitions for dump_seek() functions in binfmt_aout.c, binfmt_elf.c and binfmt_elf_fdpic.c, respectively. The only for binfmt_elf.c. My next patch will move dump_seek() into a header file in order to share the same implementations for dump_write() and dump_seek(). As the first step, this patch unify these three definitions for dump_seek() by applying the past commits that have been applied only for binfmt_elf.c. Specifically, the modification made here is part of the following commits: * d025c9db7f31fc0554ce7fb2dfc78d35a77f3487 * 7f14daa19ea36b200d237ad3ac5826ae25360461 This patch does not change a shape of corefiles. Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-02-09tree-wide: Assorted spelling fixesDaniel Mack
In particular, several occurances of funny versions of 'success', 'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address', 'beginning', 'desirable', 'separate' and 'necessary' are fixed. Signed-off-by: Daniel Mack <daniel@caiaq.de> Cc: Joe Perches <joe@perches.com> Cc: Junio C Hamano <gitster@pobox.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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>
2010-01-06FDPIC: Respect PT_GNU_STACK exec protection markings when creating NOMMU stackMike Frysinger
The current code will load the stack size and protection markings, but then only use the markings in the MMU code path. The NOMMU code path always passes PROT_EXEC to the mmap() call. While this doesn't matter to most people whilst the code is running, it will cause a pointless icache flush when starting every FDPIC application. Typically this icache flush will be of a region on the order of 128KB in size, or may be the entire icache, depending on the facilities available on the CPU. In the case where the arch default behaviour seems to be desired (EXSTACK_DEFAULT), we probe VM_STACK_FLAGS for VM_EXEC to determine whether we should be setting PROT_EXEC or not. For arches that support an MPU (Memory Protection Unit - an MMU without the virtual mapping capability), setting PROT_EXEC or not will make an important difference. It should be noted that this change also affects the executability of the brk region, since ELF-FDPIC has that share with the stack. However, this is probably irrelevant as NOMMU programs aren't likely to use the brk region, preferring instead allocation via mmap(). Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-04binfmt_elf_fdpic: Fix build breakage introduced by coredump changes.Daisuke HATAYAMA
Commit f6151dfea21496d43dbaba32cfcd9c9f404769bc introduces build breakage, so this patch fixes it together with some printk formatting cleanup. Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com> Signed-off-by: Paul Mundt <lethal@linux-sh.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>