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path: root/fs/binfmt_elf.c
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2007-01-26[PATCH] core-dumping unreadable binaries via PT_INTERPAlexey Dobriyan
Proposed patch to fix #5 in http://www.isec.pl/vulnerabilities/isec-0017-binfmt_elf.txt aka http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-1073 To reproduce, do * grab poc at the end of advisory. * add line "eph.p_memsz = 4096;" after "eph.p_filesz = 4096;" where first "4096" is something equal to or greater than 4096. * ./poc /usr/bin/sudo && ls -l Here I get with 2.6.20-rc5: -rw------- 1 ad ad 102400 2007-01-15 19:17 core ---s--x--x 2 root root 101820 2007-01-15 19:15 /usr/bin/sudo Check for MAY_READ like binfmt_misc.c does. Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-26[PATCH] i386 vDSO: use VM_ALWAYSDUMPRoland McGrath
This patch fixes core dumps to include the vDSO vma, which is left out now. It removes the special-case core writing macros, which were not doing the right thing for the vDSO vma anyway. Instead, it uses VM_ALWAYSDUMP in the vma; there is no need for the fixmap page to be installed. It handles the CONFIG_COMPAT_VDSO case by making elf_core_dump use the fake vma from get_gate_vma after real vmas in the same way the /proc/PID/maps code does. This changes core dumps so they no longer include the non-PT_LOAD phdrs from the vDSO. I made the change to add them in the first place, but in turned out that nothing ever wanted them there since the advent of NT_AUXV. It's cleaner to leave them out, and just let the phdrs inside the vDSO image speak for themselves. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-26[PATCH] Add VM_ALWAYSDUMPRoland McGrath
This patch adds the VM_ALWAYSDUMP flag for vm_flags in vm_area_struct. This provides a clean explicit way to have a vma always included in core dumps, as is needed for vDSO's. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-06Revert "[PATCH] binfmt_elf: randomize PIE binaries (2nd try)"Linus Torvalds
This reverts commit 59287c0913cc9a6c75712a775f6c1c1ef418ef3b. Hugh Dickins reports that it causes random failures on x86 with SuSE 10.2, and points out "Isn't that randomization, anywhere from 0x10000 to ELF_ET_DYN_BASE, sure to place the ET_DYN from time to time just where the comment says it's trying to avoid? I assume that somehow results in the error reported." (where the comment in question is the existing comment in the source code about mmap/brk clashes). Suggested-by: Hugh Dickins <hugh@veritas.com> Acked-by: Marcus Meissner <meissner@suse.de> Cc: Andrew Morton <akpm@osdl.org> Cc: Andi Kleen <ak@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] add process_session() helper routineCedric Le Goater
Replace occurences of task->signal->session by a new process_session() helper routine. It will be useful for pid namespaces to abstract the session pid number. Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] VFS: change struct file to use struct pathJosef "Jeff" Sipek
This patch changes struct file to use struct path instead of having independent pointers to struct dentry and struct vfsmount, and converts all users of f_{dentry,vfsmnt} in fs/ to use f_path.{dentry,mnt}. Additionally, it adds two #define's to make the transition easier for users of the f_dentry and f_vfsmnt. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] fs: remove unused variableDavid Rientjes
Removed unused 'have_pt_gnu_stack' variable. Reported by David Binderman <dcb314@hotmail.com> Signed-off-by: David Rientjes <rientjes@cs.washington.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] elf: Always define elf_addr_t in linux/elf.hMagnus Damm
Define elf_addr_t in linux/elf.h. The size of the type is determined using ELF_CLASS. This allows us to remove the defines that today are spread all over .c and .h files. Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Cc: Daniel Jacobowitz <drow@false.org> Cc: Roland McGrath <roland@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] binfmt: fix uaccess handlingHeiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] binfmt_elf: randomize PIE binaries (2nd try)Marcus Meissner
Randomizes -pie compiled binaries from 64k (0x10000) up to ELF_ET_DYN_BASE. 0 -> 64k is excluded to allow NULL ptr accesses to fail. Signed-off-by: Marcus Meissner <meissner@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-04[POWERPC] coredump: Add SPU elf notes to coredump.Dwayne Grant McConnell
This patch adds SPU elf notes to the coredump. It creates a separate note for each of /regs, /fpcr, /lslr, /decr, /decr_status, /mem, /signal1, /signal1_type, /signal2, /signal2_type, /event_mask, /event_status, /mbox_info, /ibox_info, /wbox_info, /dma_info, /proxydma_info, /object-id. A new macro, ARCH_HAVE_EXTRA_NOTES, was created for architectures to specify they have extra elf core notes. A new macro, ELF_CORE_EXTRA_NOTES_SIZE, was created so the size of the additional notes could be calculated and added to the notes phdr entry. A new macro, ELF_CORE_WRITE_EXTRA_NOTES, was created so the new notes would be written after the existing notes. The SPU coredump code resides in spufs. Stub functions are provided in the kernel which are hooked into the spufs code which does the actual work via register_arch_coredump_calls(). A new set of __spufs_<file>_read/get() functions was provided to allow the coredump code to read from the spufs files without having to lock the SPU context for each file read from. Cc: <linux-arch@vger.kernel.org> Signed-off-by: Dwayne Grant McConnell <decimal@us.ibm.com> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
2006-10-15[PATCH] Fix core files so they make sense to gdb...Petr Vandrovec
It is silly to use non-static variable for writting zeroes to the file. And more seriously, foffset in core dump file dump function was incremented too much, so some parts of core dump were shifted by size of few phdrs and notes down, so although gdb was able to load that file, it did not make lot of sense - in my test case data pages were shifted down by about 900 bytes. Signed-off-by: Petr Vandrovec <petr@vandrovec.name> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-13[PATCH] Get core dump code to work...Petr Vandrovec
The file based core dump code was broken by pipe changes - a relative llseek returns the absolute file position on success, not the relative one, so dump_seek() always failed when invoked with non-zero current position. Only success/failure can be tested with relative lseek, we have to trust kernel that on success we've got right file offset. With this fix in place I have finally real core files instead of 1KB fragments... Signed-off-by: Petr Vandrovec <petr@vandrovec.name> [ Cleaned it up a bit while here - use SEEK_CUR instead of hardcoding 1 ] Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] Support piping into commands in /proc/sys/kernel/core_patternAndi Kleen
Using the infrastructure created in previous patches implement support to pipe core dumps into programs. This is done by overloading the existing core_pattern sysctl with a new syntax: |program When the first character of the pattern is a '|' the kernel will instead threat the rest of the pattern as a command to run. The core dump will be written to the standard input of that program instead of to a file. This is useful for having automatic core dump analysis without filling up disks. The program can do some simple analysis and save only a summary of the core dump. The core dump proces will run with the privileges and in the name space of the process that caused the core dump. I also increased the core pattern size to 128 bytes so that longer command lines fit. Most of the changes comes from allowing core dumps without seeks. They are fairly straight forward though. One small incompatibility is that if someone had a core pattern previously that started with '|' they will get suddenly new behaviour. I think that's unlikely to be a real problem though. Additional background: > Very nice, do you happen to have a program that can accept this kind of > input for crash dumps? I'm guessing that the embedded people will > really want this functionality. I had a cheesy demo/prototype. Basically it wrote the dump to a file again, ran gdb on it to get a backtrace and wrote the summary to a shared directory. Then there was a simple CGI script to generate a "top 10" crashes HTML listing. Unfortunately this still had the disadvantage to needing full disk space for a dump except for deleting it afterwards (in fact it was worse because over the pipe holes didn't work so if you have a holey address map it would require more space). Fortunately gdb seems to be happy to handle /proc/pid/fd/xxx input pipes as cores (at least it worked with zsh's =(cat core) syntax), so it would be likely possible to do it without temporary space with a simple wrapper that calls it in the right way. I ran out of time before doing that though. The demo prototype scripts weren't very good. If there is really interest I can dig them out (they are currently on a laptop disk on the desk with the laptop itself being in service), but I would recommend to rewrite them for any serious application of this and fix the disk space problem. Also to be really useful it should probably find a way to automatically fetch the debuginfos (I cheated and just installed them in advance). If nobody else does it I can probably do the rewrite myself again at some point. My hope at some point was that desktops would support it in their builtin crash reporters, but at least the KDE people I talked too seemed to be happy with their user space only solution. Alan sayeth: I don't believe that piping as such as neccessarily the right model, but the ability to intercept and processes core dumps from user space is asked for by many enterprise users as well. They want to know about, capture, analyse and process core dumps, often centrally and in automated form. [akpm@osdl.org: loff_t != unsigned long] Signed-off-by: Andi Kleen <ak@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-30[PATCH] BLOCK: Move extern declarations out of fs/*.c into header files [try #6]David Howells
Create a new header file, fs/internal.h, for common definitions local to the sources in the fs/ directory. Move extern definitions that should be in header files from fs/*.c to fs/internal.h or other main header files where they span directories. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-29[PATCH] elf_core_dump: don't take tasklist_lockOleg Nesterov
do_each_thread() is rcu-safe, and all tasks which use this ->mm must sleep in wait_for_completion(&mm->core_done) at this point, so we can use RCU locks. Also, remove unneeded INIT_LIST_HEAD(new) before list_add(new, head). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] Fix unserialized task->files changingKirill Korotaev
Fixed race on put_files_struct on exec with proc. Restoring files on current on error path may lead to proc having a pointer to already kfree-d files_struct. ->files changing at exit.c and khtread.c are safe as exit_files() makes all things under lock. Found during OpenVZ stress testing. [akpm@osdl.org: add export] Signed-off-by: Pavel Emelianov <xemul@openvz.org> Signed-off-by: Kirill Korotaev <dev@openvz.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6Linus Torvalds
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (225 commits) [PATCH] Don't set calgary iommu as default y [PATCH] i386/x86-64: New Intel feature flags [PATCH] x86: Add a cumulative thermal throttle event counter. [PATCH] i386: Make the jiffies compares use the 64bit safe macros. [PATCH] x86: Refactor thermal throttle processing [PATCH] Add 64bit jiffies compares (for use with get_jiffies_64) [PATCH] Fix unwinder warning in traps.c [PATCH] x86: Allow disabling early pci scans with pci=noearly or disallowing conf1 [PATCH] x86: Move direct PCI scanning functions out of line [PATCH] i386/x86-64: Make all early PCI scans dependent on CONFIG_PCI [PATCH] Don't leak NT bit into next task [PATCH] i386/x86-64: Work around gcc bug with noreturn functions in unwinder [PATCH] Fix some broken white space in ia32_signal.c [PATCH] Initialize argument registers for 32bit signal handlers. [PATCH] Remove all traces of signal number conversion [PATCH] Don't synchronize time reading on single core AMD systems [PATCH] Remove outdated comment in x86-64 mmconfig code [PATCH] Use string instructions for Core2 copy/clear [PATCH] x86: - restore i8259A eoi status on resume [PATCH] i386: Split multi-line printk in oops output. ...
2006-09-26[PATCH] binfmt_elf: consistently use loff_tAndrew Morton
As David Howells <dhowells@redhat.com> points out, binfmt_elf sometimes uses off_t, sometimes uses loff_t. Use loff_t throughout. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] i386/x86-64: Don't randomize stack top when no randomization ↵Andi Kleen
personality is set Based on patch from Frank van Maarseveen <frankvm@frankvm.com>, but extended. Signed-off-by: Andi Kleen <ak@suse.de>
2006-07-10[PATCH] FDPIC: Move roundup() into linux/kernel.hDavid Howells
Move the roundup() macro from binfmt_elf.c into linux/kernel.h as it's generally useful. [akpm@osdl.org: nuke all the other implementations] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] binfmt_elf: fix checks for bad addressChuck Ebbert
Fix check for bad address; use macro instead of open-coding two checks. Taken from RHEL4 kernel update. From: Ernie Petrides <petrides@redhat.com> For background, the BAD_ADDR() macro should return TRUE if the address is TASK_SIZE, because that's the lowest address that is *not* valid for user-space mappings. The macro was correct in binfmt_aout.c but was wrong for the "equal to" case in binfmt_elf.c. There were two in-line validations of user-space addresses in binfmt_elf.c, which have been appropriately converted to use the corrected BAD_ADDR() macro in the patch you posted yesterday. Note that the size checks against TASK_SIZE are okay as coded. The additional changes that I propose are below. These are in the error paths for bad ELF entry addresses once load_elf_binary() has already committed to exec'ing the new image (following the tearing down of the task's original address space). The 1st hunk deals with the interp-side of the outer "if". There were two problems here. The printk() should be removed because this path can be triggered at will by a bogus interpreter image created and used by a malicious user. Further, the error code should not be ENOEXEC, because that causes the loop in search_binary_handler() to continue trying other exec handlers (twice, in fact). But it's too late for this to work correctly, because the user address space has already been torn down, and an exec() failure cannot be returned to the user code because the code no longer exists. The only recovery is to force a SIGSEGV, but it's best to terminate the search loop immediately. I somewhat arbitrarily chose EINVAL as a fallback error code, but any error returned by load_elf_interp() will override that (but this value will never be seen by user-space). The 2nd hunk deals with the non-interp-side of the outer "if". There were two problems here as well. The SIGSEGV needs to be forced, because a prior sigaction() syscall might have set the associated disposition to SIG_IGN. And the ENOEXEC should be changed to EINVAL as described above. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Ernie Petrides <petrides@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] binflt_elf: remove more castsJesper Juhl
Remove redundant casts from NEW_AUX_ENT() arguments in fs/binfmt_elf.c Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] binfmt_elf: CodingStyle cleanup and remove some pointless castsJesper Juhl
Do a CodingStyle cleanup of fs/binfmt_elf.c and also remove some pointless casts of kmalloc() return values in the same file. Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-22[PATCH] remove steal_locks()Miklos Szeredi
This patch removes the steal_locks() function. steal_locks() doesn't work correctly with any filesystem that does it's own lock management, including NFS, CIFS, etc. In addition it has weird semantics on local filesystems in case tasks sharing file-descriptor tables are doing POSIX locking operations in parallel to execve(). The steal_locks() function has an effect on applications doing: clone(CLONE_FILES) /* in child */ lock execve lock POSIX locks acquired before execve (by "child", "parent" or any further task sharing files_struct) will after the execve be owned exclusively by "child". According to Chris Wright some LSB/LTP kind of suite triggers without the stealing behavior, but there's no known real-world application that would also fail. Apps using NPTL are not affected, since all other threads are killed before execve. Apps using LinuxThreads are only affected if they - have multiple threads during exec (LinuxThreads doesn't kill other threads, the app may do it with pthread_kill_other_threads_np()) - rely on POSIX locks being inherited across exec Both conditions are documented, but not their interaction. Apps using clone() natively are affected if they - use clone(CLONE_FILES) - rely on POSIX locks being inherited across exec The above scenarios are unlikely, but possible. If the patch is vetoed, there's a plan B, that involves mostly keeping the weird stealing semantics, but changing the way lock ownership is handled so that network and local filesystems work consistently. That would add more complexity though, so this solution seems to be preferred by most people. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Matthew Wilcox <willy@debian.org> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Steven French <sfrench@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25[PATCH] x86_64: Increase the variability of the process stack on 64bit ↵Andi Kleen
architectures 8MB is not really very random, use 1GB (or more with larger page sizes) instead. Also use the low bits of the random generator output now instead of throwing them away. Only enabled on x86-64 right now. Other architectures need to add a suitable STACK_RND_MASK Cc: mingo@elte.hu Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25[PATCH] remove needless check in binfmt_elf.cCarsten Otte
Local variable i is unsigned int and thus cannot be negative. (akpm: unsigneds shouldn't be called `i'. This value cannot possibly be negative anyway). Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25[PATCH] use kzalloc and kcalloc in core fs codeOliver Neukum
Signed-off-by: Oliver Neukum <oliver@neukum.name> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-26[PATCH] x86_64: Check for bad elf entry address.Suresh Siddha
Fixes a local DOS on Intel systems that lead to an endless recursive fault. AMD machines don't seem to be affected. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14[PATCH] Unlinline a bunch of other functionsArjan van de Ven
Remove the "inline" keyword from a bunch of big functions in the kernel with the goal of shrinking it by 30kb to 40kb Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Jeff Garzik <jgarzik@pobox.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11missing printk loglevel and tiny tiny whitespace change in binfmt_elf()Jesper Juhl
Patch adds a mising printk loglevel (I think KERN_WARNING is appropriate here) in fs/binfmt_elf.c, and while I was there I made some tiny tiny tiny adjustments to whitespacing in the neighborhood. Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-01-10[PATCH] fs/binfmt_elf: Remove unneeded kmalloc() return value castsJesper Juhl
Remove unneeded casts of kmalloc() return value in binfmt_elf. Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] tiny: Configure ELF core dump supportMatt Mackall
configurable support for ELF core dumps text data bss dec hex filename 3330172 529036 190556 4049764 3dcb64 vmlinux-baseline 3325552 528912 190556 4045020 3db8dc vmlinux-no-elf add/remove: 0/8 grow/shrink: 0/0 up/down: 0/-4424 (-4424) function old new delta fill_note 32 - -32 maydump 58 - -58 dump_seek 67 - -67 writenote 180 - -180 elf_dump_thread_status 274 - -274 fill_psinfo 308 - -308 fill_prstatus 466 - -466 elf_core_dump 3039 - -3039 Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Fix handling of ELF segments with zero filesizeDavid Gibson
mmap() returns -EINVAL if given a zero length, and thus elf_map() in binfmt_elf.c does likewise if it attempts to map a (page-aligned) ELF segment with zero filesize. Such a situation never arises with the default linker scripts, but there's nothing inherently wrong with zero-filesize (but non-zero memsize) ELF segments. Custom linker scripts can generate them, and the kernel should be able to map them; this patch makes it so. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] kfree cleanup: fsJesper Juhl
This is the fs/ part of the big kfree cleanup patch. Remove pointless checks for NULL prior to calling kfree() in fs/. Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] Don't uselessly export task_struct to userspace in core dumpsEric W. Biederman
task_struct is an internal structure to the kernel with a lot of good information, that is probably interesting in core dumps. However there is no way for user space to know what format that information is in making it useless. I grepped the GDB 6.3 source code and NT_TASKSTRUCT while defined is not used anywhere else. So I would be surprised if anyone notices it is missing. In addition exporting kernel pointers to all the interesting kernel data structures sounds like the very definition of an information leak. I haven't a clue what someone with evil intentions could do with that information, but in any attack against the kernel it looks like this is the perfect tool for aiming that attack. So since NT_TASKSTRUCT is useless as currently defined and is potentially dangerous, let's just not export it. (akpm: Daniel Jacobowitz <dan@debian.org> "would be amazed" if anything was using NT_TASKSTRUCT). Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: mm_init set_mm_countersHugh Dickins
How is anon_rss initialized? In dup_mmap, and by mm_alloc's memset; but that's not so good if an mm_counter_t is a special type. And how is rss initialized? By set_mm_counter, all over the place. Come on, we just need to initialize them both at once by set_mm_counter in mm_init (which follows the memcpy when forking). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-11[PATCH] binfmt_elf bss padding fixakpm@osdl.org
Nir Tzachar <tzachar@cs.bgu.ac.il> points out that if an ELF file specifies a zero-length bss at a whacky address, we cannot load that binary because padzero() tries to zero out the end of the page at the whacky address, and that may not be writeable. See also http://bugzilla.kernel.org/show_bug.cgi?id=5411 So teach load_elf_binary() to skip the bss settng altogether if the elf file has a zero-length bss segment. Cc: Roland McGrath <roland@redhat.com> Cc: Daniel Jacobowitz <dan@debian.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] Avoiding mmap fragmentationWolfgang Wander
Ingo recently introduced a great speedup for allocating new mmaps using the free_area_cache pointer which boosts the specweb SSL benchmark by 4-5% and causes huge performance increases in thread creation. The downside of this patch is that it does lead to fragmentation in the mmap-ed areas (visible via /proc/self/maps), such that some applications that work fine under 2.4 kernels quickly run out of memory on any 2.6 kernel. The problem is twofold: 1) the free_area_cache is used to continue a search for memory where the last search ended. Before the change new areas were always searched from the base address on. So now new small areas are cluttering holes of all sizes throughout the whole mmap-able region whereas before small holes tended to close holes near the base leaving holes far from the base large and available for larger requests. 2) the free_area_cache also is set to the location of the last munmap-ed area so in scenarios where we allocate e.g. five regions of 1K each, then free regions 4 2 3 in this order the next request for 1K will be placed in the position of the old region 3, whereas before we appended it to the still active region 1, placing it at the location of the old region 2. Before we had 1 free region of 2K, now we only get two free regions of 1K -> fragmentation. The patch addresses thes issues by introducing yet another cache descriptor cached_hole_size that contains the largest known hole size below the current free_area_cache. If a new request comes in the size is compared against the cached_hole_size and if the request can be filled with a hole below free_area_cache the search is started from the base instead. The results look promising: Whereas 2.6.12-rc4 fragments quickly and my (earlier posted) leakme.c test program terminates after 50000+ iterations with 96 distinct and fragmented maps in /proc/self/maps it performs nicely (as expected) with thread creation, Ingo's test_str02 with 20000 threads requires 0.7s system time. Taking out Ingo's patch (un-patch available per request) by basically deleting all mentions of free_area_cache from the kernel and starting the search for new memory always at the respective bases we observe: leakme terminates successfully with 11 distinctive hardly fragmented areas in /proc/self/maps but thread creating is gringdingly slow: 30+s(!) system time for Ingo's test_str02 with 20000 threads. Now - drumroll ;-) the appended patch works fine with leakme: it ends with only 7 distinct areas in /proc/self/maps and also thread creation seems sufficiently fast with 0.71s for 20000 threads. Signed-off-by: Wolfgang Wander <wwc@rentec.com> Credit-to: "Richard Purdie" <rpurdie@rpsys.net> Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> (partly) Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-16[PATCH] Fix large core dumps with a 32-bit off_tDaniel Jacobowitz
The ELF core dump code has one use of off_t when writing out segments. Some of the segments may be passed the 2GB limit of an off_t, even on a 32-bit system, so it's important to use loff_t instead. This fixes a corrupted core dump in the bigcore test in GDB's testsuite. Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-16[PATCH] fix Linux kernel ELF core dump privilege elevationGreg Kroah-Hartman
As reported by Paul Starzetz <ihaquer@isec.pl> Reference: CAN-2005-1263 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-04-28[PATCH] Fix error recovery path for arch_setup_additional_pagesRoland McGrath
If arch_setup_additional_pages fails, the error path will do some double-frees. This fixes it. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16[PATCH] ppc64: Improve mapping of vDSOBenjamin Herrenschmidt
This patch reworks the way the ppc64 is mapped in user memory by the kernel to make it more robust against possible collisions with executable segments. Instead of just whacking a VMA at 1Mb, I now use get_unmapped_area() with a hint, and I moved the mapping of the vDSO to after the mapping of the various ELF segments and of the interpreter, so that conflicts get caught properly (it still has to be before create_elf_tables since the later will fill the AT_SYSINFO_EHDR with the proper address). While I was at it, I also changed the 32 and 64 bits vDSO's to link at their "natural" address of 1Mb instead of 0. This is the address where they are normally mapped in absence of conflict. By doing so, it should be possible to properly prelink one it's been verified to work on glibc. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!