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2009-09-11scsi,block: update SCSI to handle mixed merge failuresTejun Heo
Update scsi_io_completion() such that it only fails requests till the next error boundary and retry the leftover. This enables block layer to merge requests with different failfast settings and still behave correctly on errors. Allow merge of requests of different failfast settings. As SCSI is currently the only subsystem which follows failfast status, there's no need to worry about other block drivers for now. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Niel Lambrechts <niel.lambrechts@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11block: implement mixed merge of different failfast requestsTejun Heo
Failfast has characteristics from other attributes. When issuing, executing and successuflly completing requests, failfast doesn't make any difference. It only affects how a request is handled on failure. Allowing requests with different failfast settings to be merged cause normal IOs to fail prematurely while not allowing has performance penalties as failfast is used for read aheads which are likely to be located near in-flight or to-be-issued normal IOs. This patch introduces the concept of 'mixed merge'. A request is a mixed merge if it is merge of segments which require different handling on failure. Currently the only mixable attributes are failfast ones (or lack thereof). When a bio with different failfast settings is added to an existing request or requests of different failfast settings are merged, the merged request is marked mixed. Each bio carries failfast settings and the request always tracks failfast state of the first bio. When the request fails, blk_rq_err_bytes() can be used to determine how many bytes can be safely failed without crossing into an area which requires further retrials. This allows request merging regardless of failfast settings while keeping the failure handling correct. This patch only implements mixed merge but doesn't enable it. The next one will update SCSI to make use of mixed merge. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Niel Lambrechts <niel.lambrechts@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11block: use the same failfast bits for bio and requestTejun Heo
bio and request use the same set of failfast bits. This patch makes the following changes to simplify things. * enumify BIO_RW* bits and reorder bits such that BIOS_RW_FAILFAST_* bits coincide with __REQ_FAILFAST_* bits. * The above pushes BIO_RW_AHEAD out of sync with __REQ_FAILFAST_DEV but the matching is useless anyway. init_request_from_bio() is responsible for setting FAILFAST bits on FS requests and non-FS requests never use BIO_RW_AHEAD. Drop the code and comment from blk_rq_bio_prep(). * Define REQ_FAILFAST_MASK which is OR of all FAILFAST bits and simplify FAILFAST flags handling in init_request_from_bio(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-10md: Fix "strchr" [drivers/md/dm-log-userspace.ko] undefined!Geert Uytterhoeven
Commit b8313b6da7e2e7c7f47d93d8561969a3ff9ba0ea ("dm log: remove incorrect field from userspace table output") added a call to strstr() with a single-character "needle" string parameter. Unfortunately some versions of gcc replace such calls to strstr() by calls to strchr() behind our back. This causes linking errors if strchr() is defined as an inline function in <asm/string.h> (e.g. on m68k): | WARNING: "strchr" [drivers/md/dm-log-userspace.ko] undefined! Avoid this by explicitly calling strchr() instead. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-09Merge branch 'lookup-permissions-cleanup'Linus Torvalds
* lookup-permissions-cleanup: jffs2/jfs/xfs: switch over to 'check_acl' rather than 'permission()' ext[234]: move over to 'check_acl' permission model shmfs: use 'check_acl' instead of 'permission' Make 'check_acl()' a first-class filesystem op Simplify exec_permission_lite(), part 3 Simplify exec_permission_lite() further Simplify exec_permission_lite() logic Do not call 'ima_path_check()' for each path component
2009-09-09binfmt_elf: fix PT_INTERP bss handlingRoland McGrath
In fs/binfmt_elf.c, load_elf_interp() calls padzero() for .bss even if the PT_LOAD has no PROT_WRITE and no .bss. This generates EFAULT. Here is a small test case. (Yes, there are other, useful PT_INTERP which have only .text and no .data/.bss.) ----- ptinterp.S _start: .globl _start nop int3 ----- $ gcc -m32 -nostartfiles -nostdlib -o ptinterp ptinterp.S $ gcc -m32 -Wl,--dynamic-linker=ptinterp -o hello hello.c $ ./hello Segmentation fault # during execve() itself After applying the patch: $ ./hello Trace trap # user-mode execution after execve() finishes If the ELF headers are actually self-inconsistent, then dying is fine. But having no PROT_WRITE segment is perfectly normal and correct if there is no segment with p_memsz > p_filesz (i.e. bss). John Reiser suggested checking for PROT_WRITE in the bss logic. I think it makes most sense to simply apply the bss logic only when there is bss. This patch looks less trivial than it is due to some reindentation. It just moves the "if (last_bss > elf_bss) {" test up to include the partial-page bss logic as well as the more-pages bss logic. Reported-by: John Reiser <jreiser@bitwagon.com> Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-09Linux 2.6.31v2.6.31Linus Torvalds
2009-09-09aoe: allocate unused request_queue for sysfsEd Cashin
Andy Whitcroft reported an oops in aoe triggered by use of an incorrectly initialised request_queue object: [ 2645.959090] kobject '<NULL>' (ffff880059ca22c0): tried to add an uninitialized object, something is seriously wrong. [ 2645.959104] Pid: 6, comm: events/0 Not tainted 2.6.31-5-generic #24-Ubuntu [ 2645.959107] Call Trace: [ 2645.959139] [<ffffffff8126ca2f>] kobject_add+0x5f/0x70 [ 2645.959151] [<ffffffff8125b4ab>] blk_register_queue+0x8b/0xf0 [ 2645.959155] [<ffffffff8126043f>] add_disk+0x8f/0x160 [ 2645.959161] [<ffffffffa01673c4>] aoeblk_gdalloc+0x164/0x1c0 [aoe] The request queue of an aoe device is not used but can be allocated in code that does not sleep. Bruno bisected this regression down to cd43e26f071524647e660706b784ebcbefbd2e44 block: Expose stacked device queues in sysfs "This seems to generate /sys/block/$device/queue and its contents for everyone who is using queues, not just for those queues that have a non-NULL queue->request_fn." Addresses http://bugs.launchpad.net/bugs/410198 Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13942 Note that embedding a queue inside another object has always been an illegal construct, since the queues are reference counted and must persist until the last reference is dropped. So aoe was always buggy in this respect (Jens). Signed-off-by: Ed Cashin <ecashin@coraid.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Bruno Premont <bonbons@linux-vserver.org> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-08i915: disable interrupts before tearing down GEM stateLinus Torvalds
Reinette Chatre reports a frozen system (with blinking keyboard LEDs) when switching from graphics mode to the text console, or when suspending (which does the same thing). With netconsole, the oops turned out to be BUG: unable to handle kernel NULL pointer dereference at 0000000000000084 IP: [<ffffffffa03ecaab>] i915_driver_irq_handler+0x26b/0xd20 [i915] and it's due to the i915_gem.c code doing drm_irq_uninstall() after having done i915_gem_idle(). And the i915_gem_idle() path will do i915_gem_idle() -> i915_gem_cleanup_ringbuffer() -> i915_gem_cleanup_hws() -> dev_priv->hw_status_page = NULL; but if an i915 interrupt comes in after this stage, it may want to access that hw_status_page, and gets the above NULL pointer dereference. And since the NULL pointer dereference happens from within an interrupt, and with the screen still in graphics mode, the common end result is simply a silently hung machine. Fix it by simply uninstalling the irq handler before idling rather than after. Fixes http://bugzilla.kernel.org/show_bug.cgi?id=13819 Reported-and-tested-by: Reinette Chatre <reinette.chatre@intel.com> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-08jffs2/jfs/xfs: switch over to 'check_acl' rather than 'permission()'Linus Torvalds
This avoids an indirect call in the VFS for each path component lookup. Well, at least as long as you own the directory in question, and the ACL check is unnecessary. Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-08ext[234]: move over to 'check_acl' permission modelLinus Torvalds
Don't implement per-filesystem 'extX_permission()' functions that have to be called for every path component operation, and instead just expose the actual ACL checking so that the VFS layer can now do it for us. Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-08shmfs: use 'check_acl' instead of 'permission'Linus Torvalds
shmfs wants purely standard POSIX ACL semantics, so we can use the new generic VFS layer POSIX ACL checking rather than cooking our own 'permission()' function. Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-08Make 'check_acl()' a first-class filesystem opLinus Torvalds
This is stage one in flattening out the callchains for the common permission testing. Rather than have most filesystem implement their own inode->i_op->permission function that just calls back down to the VFS layers 'generic_permission()' with the per-filesystem ACL checking function, the filesystem can just expose its 'check_acl' function directly, and let the VFS layer do everything for it. This is all just preparatory - no filesystem actually enables this yet. Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-08Simplify exec_permission_lite(), part 3Linus Torvalds
Don't call down to the generic inode_permission() function just to call the inode-specific permission function - just do it directly. The generic inode_permission() code does things like checking MAY_WRITE and devcgroup_inode_permission(), neither of which are relevant for the light pathname walk permission checks (we always do just MAY_EXEC, and the inode is never a special device). Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-08Simplify exec_permission_lite() furtherLinus Torvalds
This function is only called for path components that are already known to be directories (they have a '->lookup' method). So don't bother doing that whole S_ISDIR() testing, the whole point of the 'lite()' version is that we know that we are looking at a directory component, and that we're only checking name lookup permission. Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-08Simplify exec_permission_lite() logicLinus Torvalds
Instead of returning EAGAIN and having the caller do something special for that case, just do the special case directly. Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-08Do not call 'ima_path_check()' for each path componentLinus Torvalds
Not only is that a supremely timing-critical path, but it's hopefully some day going to be lockless for the common case, and ima can't do that. Plus the integrity code doesn't even care about non-regular files, so it was always a total waste of time and effort. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-08drm/i915: fix mask bits settingZhenyu Wang
eDP is exclusive connector too, and add missing crtc_mask setting for TV. This fixes http://bugzilla.kernel.org/show_bug.cgi?id=14139 Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> Reported-and-tested-by: Carlos R. Mafra <crmafra2@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-07Merge branch 'drm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 * 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: drm/radeon/kms: add LTE/GTE discard + rv515 two sided stencil register.
2009-09-07Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: IMA: update ima_counts_put
2009-09-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: gianfar: Fix build.
2009-09-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6: pcmcia: add CNF-CDROM-ID for ide
2009-09-07Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel: agp/intel: support for new chip variant of IGDNG mobile drm/i915: Unref old_obj on get_fence_reg() error path drm/i915: increase default latency constant (v2 w/comment)
2009-09-07drm/radeon/kms: add LTE/GTE discard + rv515 two sided stencil register.Dave Airlie
This adds some rv350+ register for LTE/GTE discard, and enables the rv515 two sided stencil register. It also disables the DEPTHXY_OFFSET register which can be used to workaround the CS checker. Moves rs690 to proper place in rs600 and uses correct table on rs600. Signed-off-by: Dave Airlie <airlied@redhat.com>
2009-09-07IMA: update ima_counts_putMimi Zohar
- As ima_counts_put() may be called after the inode has been freed, verify that the inode is not NULL, before dereferencing it. - Maintain the IMA file counters in may_open() properly, decrementing any counter increments on subsequent errors. Reported-by: Ciprian Docan <docan@eden.rutgers.edu> Reported-by: J.R. Okajima <hooanon05@yahoo.co.jp> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com Signed-off-by: James Morris <jmorris@namei.org>
2009-09-06gianfar: Fix build.David S. Miller
Reported by Michael Guntsche <mike@it-loops.com> -------------------- Commit 38bddf04bcfe661fbdab94888c3b72c32f6873b3 gianfar: gfar_remove needs to call unregister_netdev() breaks the build of the gianfar driver because "dev" is undefined in this function. To quickly test rc9 I changed this to priv->ndev but I do not know if this is the correct one. -------------------- Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-05Linux 2.6.31-rc9v2.6.31-rc9Linus Torvalds
2009-09-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: firewire: sbp2: fix freeing of unallocated memory firewire: ohci: fix Ricoh R5C832, video reception firewire: ohci: fix Agere FW643 and multiple cameras firewire: core: fix crash in iso resource management
2009-09-05powerpc: Fix i8259 interrupt driver kernel crash on ML510Roderick Colenbrander
This patch fixes a null pointer exception caused by removal of 'ack()' for level interrupts in the Xilinx interrupt driver. A recent change to the xilinx interrupt controller removed the ack hook for level irqs. Signed-off-by: Roderick Colenbrander <thunderbird2k@gmail.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05Merge git://git.infradead.org/~dwmw2/mtd-2.6.31Linus Torvalds
* git://git.infradead.org/~dwmw2/mtd-2.6.31: JFFS2: add missing verify buffer allocation/deallocation mtd: nftl: fix offset alignments mtd: nftl: write support is broken mtd: m25p80: fix null pointer dereference bug
2009-09-05Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: Allow changing max_sectors_kb above the default 512
2009-09-05Merge branch 'fix/oxygen' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 * 'fix/oxygen' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: sound: oxygen: handle cards with missing EEPROM sound: oxygen: fix MCLK rate for 192 kHz playback
2009-09-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: tc: Fix unitialized kernel memory leak pkt_sched: Revert tasklet_hrtimer changes. net: sk_free() should be allowed right after sk_alloc() gianfar: gfar_remove needs to call unregister_netdev() ipw2200: firmware DMA loading rework
2009-09-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: skcipher - Fix skcipher_dequeue_givcrypt NULL test
2009-09-05Merge branch 'fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: [CPUFREQ] Re-enable cpufreq suspend and resume code
2009-09-05Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] fix csum_ipv6_magic() [IA64] Fix warning in dma-mapping.c
2009-09-05Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds
* 'for-linus' of git://oss.sgi.com/xfs/xfs: xfs: actually enable the swapext compat handler
2009-09-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: nilfs2: fix preempt count underflow in nilfs_btnode_prepare_change_key
2009-09-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: don't assume existence of cpu0
2009-09-05Merge branch 'slab/urgent' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: slub: Fix kmem_cache_destroy() with SLAB_DESTROY_BY_RCU
2009-09-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dmLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: dm snapshot: fix on disk chunk size validation dm exception store: split set_chunk_size dm snapshot: fix header corruption race on invalidation dm snapshot: refactor zero_disk_area to use chunk_io dm log: userspace add luid to distinguish between concurrent log instances dm raid1: do not allow log_failure variable to unset after being set dm log: remove incorrect field from userspace table output dm log: fix userspace status output dm stripe: expose correct io hints dm table: add more context to terse warning messages dm table: fix queue_limit checking device iterator dm snapshot: implement iterate devices dm multipath: fix oops when request based io fails when no paths
2009-09-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: PCI SR-IOV: correct broken resource alignment calculations
2009-09-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6: sparc64: Fix bootup with mcount in some configs. sparc64: Kill spurious NMI watchdog triggers by increasing limit to 30 seconds.
2009-09-05Merge branch 'perfcounters-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf_counter/powerpc: Fix cache event codes for POWER7 perf_counter: Fix /0 bug in swcounters perf_counters: Increase paranoia level
2009-09-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: atkbd - add Compaq Presario R4000-series repeat quirk Input: i8042 - add Acer Aspire 5536 to the nomux list
2009-09-05ext2: fix unbalanced kmap()/kunmap()Nicolas Pitre
In ext2_rename(), dir_page is acquired through ext2_dotdot(). It is then released through ext2_set_link() but only if old_dir != new_dir. Failing that, the pkmap reference count is never decremented and the page remains pinned forever. Repeat that a couple times with highmem pages and all pkmap slots get exhausted, and every further kmap() calls end up stalling on the pkmap_map_wait queue at which point the whole system comes to a halt. Signed-off-by: Nicolas Pitre <nico@marvell.com> Acked-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05Merge branch 'upstream-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2 * 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: ocfs2: ocfs2_write_begin_nolock() should handle len=0 ocfs2: invalidate dentry if its dentry_lock isn't initialized.
2009-09-05pty: don't limit the writes to 'pty_space()' inside 'pty_write()'Linus Torvalds
The whole write-room thing is something that is up to the _caller_ to worry about, not the pty layer itself. The total buffer space will still be limited by the buffering routines themselves, so there is no advantage or need in having pty_write() artificially limit the size somehow. And what happened was that the caller (the n_tty line discipline, in this case) may have verified that there is room for 2 bytes to be written (for NL -> CRNL expansion), and it used to then do those writes as two single-byte writes. And if the first byte written (CR) then caused a new tty buffer to be allocated, pty_space() may have returned zero when trying to write the second byte (LF), and then incorrectly failed the write - leading to a lost newline character. This should finally fix http://bugzilla.kernel.org/show_bug.cgi?id=14015 Reported-by: Mikael Pettersson <mikpe@it.uu.se> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05n_tty: do O_ONLCR translation as a single writeLinus Torvalds
When translating CR to CRNL in the n_tty line discipline, we did it as two tty_put_char() calls. Which works, but is stupid, and has caused problems before too with bad interactions with the write_room() logic. The generic USB serial driver had that problem, for example. Now the pty layer had similar issues after being moved to the generic tty buffering code (in commit d945cb9cce20ac7143c2de8d88b187f62db99bdc: "pty: Rework the pty layer to use the normal buffering logic"). So stop doing the silly separate two writes, and do it as a single write instead. That's what the n_tty layer already does for the space expansion of tabs (XTABS), and it means that we'll now always have just a single write for the CRNL to match the single 'tty_write_room()' test, which hopefully means that the next time somebody screws up buffering, it won't cause weeks of debugging. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05exec: do not sleep in TASK_TRACED under ->cred_guard_mutexOleg Nesterov
Tom Horsley reports that his debugger hangs when it tries to read /proc/pid_of_tracee/maps, this happens since "mm_for_maps: take ->cred_guard_mutex to fix the race with exec" 04b836cbf19e885f8366bccb2e4b0474346c02d commit in 2.6.31. But the root of the problem lies in the fact that do_execve() path calls tracehook_report_exec() which can stop if the tracer sets PT_TRACE_EXEC. The tracee must not sleep in TASK_TRACED holding this mutex. Even if we remove ->cred_guard_mutex from mm_for_maps() and proc_pid_attr_write(), another task doing PTRACE_ATTACH should not hang until it is killed or the tracee resumes. With this patch do_execve() does not use ->cred_guard_mutex directly and we do not hold it throughout, instead: - introduce prepare_bprm_creds() helper, it locks the mutex and calls prepare_exec_creds() to initialize bprm->cred. - install_exec_creds() drops the mutex after commit_creds(), and thus before tracehook_report_exec()->ptrace_stop(). or, if exec fails, free_bprm() drops this mutex when bprm->cred != NULL which indicates install_exec_creds() was not called. Reported-by: Tom Horsley <tom.horsley@att.net> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>