lwn.git/fs/binfmt_elf_fdpic.c, branch docs-next-merge

coredump: fix dumping through pipes

2016-06-08T02:07:09+00:00

The offset in the core file used to be tracked with ->written field of the coredump_params structure. The field was retired in favour of file->f_pos. However, ->f_pos is not maintained for pipes which leads to breakage. Restore explicit tracking of the offset in coredump_params. Introduce ->pos field for this purpose since ->written was already reused. Fixes: a00839395103 ("get rid of coredump_params->written"). Reported-by: Zbigniew Jędrzejewski-Szmek Signed-off-by: Mateusz Guzik Reviewed-by: Omar Sandoval Signed-off-by: Al Viro

Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-05-18T18:51:59+00:00

Pull misc vfs cleanups from Al Viro: "Assorted cleanups and fixes all over the place" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: coredump: only charge written data against RLIMIT_CORE coredump: get rid of coredump_params->written ecryptfs_lookup(): try either only encrypted or plaintext name ecryptfs: avoid multiple aliases for directories bpf: reject invalid names right in ->lookup() __d_alloc(): treat NULL name as QSTR("/", 1) mtd: switch ubi_open_volume_path() to vfs_stat() mtd: switch open_mtd_by_chdev() to use of vfs_stat()

coredump: get rid of coredump_params->written

2016-05-12T20:55:50+00:00

cprm->written is redundant with cprm->file->f_pos, so use that instead. Signed-off-by: Omar Sandoval Signed-off-by: Al Viro

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

2016-04-04T17:41:08+00:00

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: - << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ; - >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ; - 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 Acked-by: Michal Hocko Signed-off-by: Linus Torvalds

Merge tag 'libnvdimm-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2015-11-10T20:07:22+00:00

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()

Merge branch 'akpm' (patches from Andrew)

2015-11-10T05:05:13+00:00

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 : (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 ...

fs/binfmt_elf_fdpic.c: provide NOMMU loader for regular ELF binaries

2015-11-09T23:11:24+00:00

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 Acked-by: Greg Ungerer Cc: Paul Gortmaker Cc: Matt Mackall Cc: David Woodhouse Cc: Alexander Viro Cc: David Howells Cc: Oleg Endo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

coredump: add DAX filtering for FDPIC ELF coredumps

2015-11-09T18:29:54+00:00

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 Acked-by: Jeff Moyer Signed-off-by: Dan Williams

fs/binfmt_elf_fdpic.c: fix brk area overlap with stack on NOMMU

2015-10-25T23:02:32+00:00

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 Acked-by: David Howells Signed-off-by: Greg Ungerer

handle suicide on late failure exits in execve() in search_binary_handler()

2014-10-09T06:39:00+00:00

... 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