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path: root/drivers/char/mem.c
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2012-07-11powerpc: Disable /dev/port interface on systems without an ISA bridgeHaren Myneni1-1/+10
Some power systems do not have legacy ISA devices. So, /dev/port is not a valid interface on these systems. User level tools such as kbdrate is trying to access the device using this interface which is causing the system crash. This patch will fix this issue by not creating this interface on these powerpc systems. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-05-10printk - fix compilation for CONFIG_PRINTK=nKay Sievers1-0/+2
Reported-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-08kmsg: export printk records to the /dev/kmsg interfaceKay Sievers1-60/+1
Support for multiple concurrent readers of /dev/kmsg, with read(), seek(), poll() support. Output of message sequence numbers, to allow userspace log consumers to reliably reconnect and reconstruct their state at any given time. After open("/dev/kmsg"), read() always returns *all* buffered records. If only future messages should be read, SEEK_END can be used. In case records get overwritten while /dev/kmsg is held open, or records get faster overwritten than they are read, the next read() will return -EPIPE and the current reading position gets updated to the next available record. The passed sequence numbers allow the log consumer to calculate the amount of lost messages. [root@mop ~]# cat /dev/kmsg 5,0,0;Linux version 3.4.0-rc1+ (kay@mop) (gcc version 4.7.0 20120315 ... 6,159,423091;ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff]) 7,160,424069;pci_root PNP0A03:00: host bridge window [io 0x0000-0x0cf7] (ignored) SUBSYSTEM=acpi DEVICE=+acpi:PNP0A03:00 6,339,5140900;NET: Registered protocol family 10 30,340,5690716;udevd[80]: starting version 181 6,341,6081421;FDC 0 is a S82078B 6,345,6154686;microcode: CPU0 sig=0x623, pf=0x0, revision=0x0 7,346,6156968;sr 1:0:0:0: Attached scsi CD-ROM sr0 SUBSYSTEM=scsi DEVICE=+scsi:1:0:0:0 6,347,6289375;microcode: CPU1 sig=0x623, pf=0x0, revision=0x0 Cc: Karel Zak <kzak@redhat.com> Tested-by: William Douglas <william.douglas@intel.com> Signed-off-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-08printk: convert byte-buffer to variable-length record bufferKay Sievers1-17/+38
- Record-based stream instead of the traditional byte stream buffer. All records carry a 64 bit timestamp, the syslog facility and priority in the record header. - Records consume almost the same amount, sometimes less memory than the traditional byte stream buffer (if printk_time is enabled). The record header is 16 bytes long, plus some padding bytes at the end if needed. The byte-stream buffer needed 3 chars for the syslog prefix, 15 char for the timestamp and a newline. - Buffer management is based on message sequence numbers. When records need to be discarded, the reading heads move on to the next full record. Unlike the byte-stream buffer, no old logged lines get truncated or partly overwritten by new ones. Sequence numbers also allow consumers of the log stream to get notified if any message in the stream they are about to read gets discarded during the time of reading. - Better buffered IO support for KERN_CONT continuation lines, when printk() is called multiple times for a single line. The use of KERN_CONT is now mandatory to use continuation; a few places in the kernel need trivial fixes here. The buffering could possibly be extended to per-cpu variables to allow better thread-safety for multiple printk() invocations for a single line. - Full-featured syslog facility value support. Different facilities can tag their messages. All userspace-injected messages enforce a facility value > 0 now, to be able to reliably distinguish them from the kernel-generated messages. Independent subsystems like a baseband processor running its own firmware, or a kernel-related userspace process can use their own unique facility values. Multiple independent log streams can co-exist that way in the same buffer. All share the same global sequence number counter to ensure proper ordering (and interleaving) and to allow the consumers of the log to reliably correlate the events from different facilities. Tested-by: William Douglas <william.douglas@intel.com> Signed-off-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-04switch device_get_devnode() and ->devnode() to umode_t *Al Viro1-2/+2
both callers of device_get_devnode() are only interested in lower 16bits and nobody tries to return anything wider than 16bit anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-01drivers/char: Add export.h for EXPORT_SYMBOL/THIS_MODULE as requiredPaul Gortmaker1-0/+1
They will need it called out explicitly in the near future due to a module.h usage cleanup that removes its implicit presence everywhere. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-04-20kmsg: properly support writev to avoid interleaved printk lines fixAndrew Morton1-3/+4
make `len' size_t, avoid multiple-assignments. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Lennart Poettering <lennart@poettering.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-20printk: /dev/kmsg - properly support writev() to avoid interleaved printk() ↵Kay Sievers1-15/+26
lines printk: /dev/kmsg - properly support writev() to avoid interleaved printk lines We should avoid calling printk() in a loop, when we pass a single string to /dev/kmsg with writev(). Cc: Lennart Poettering <lennart@poettering.net> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-24drivers/char/mem.c: clean up the codeChangli Gao1-4/+1
Reduce the lines of code and simplify the logic. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26vfs: introduce FMODE_UNSIGNED_OFFSET for allowing negative f_posKAMEZAWA Hiroyuki1-0/+4
Now, rw_verify_area() checsk f_pos is negative or not. And if negative, returns -EINVAL. But, some special files as /dev/(k)mem and /proc/<pid>/mem etc.. has negative offsets. And we can't do any access via read/write to the file(device). So introduce FMODE_UNSIGNED_OFFSET to allow negative file offsets. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-22Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds1-0/+3
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
2010-10-15llseek: automatically add .llseek fopArnd Bergmann1-0/+3
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-09-22char: Mark /dev/zero and /dev/kmem as not capable of writebackJan Kara1-1/+2
These devices don't do any writeback but their device inodes still can get dirty so mark bdi appropriately so that bdi code does the right thing and files inodes to lists of bdi carrying the device inodes. Cc: stable@kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-06Fix init ordering of /dev/console vs callers of modprobeDavid Howells1-1/+1
Make /dev/console get initialised before any initialisation routine that invokes modprobe because if modprobe fails, it's going to want to open /dev/console, presumably to write an error message to. The problem with that is that if the /dev/console driver is not yet initialised, the chardev handler will call request_module() to invoke modprobe, which will fail, because we never compile /dev/console as a module. This will lead to a modprobe loop, showing the following in the kernel log: request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 This can happen, for example, when the built in md5 module can't find the built in cryptomgr module (because the latter fails to initialise). The md5 module comes before the call to tty_init(), presumably because 'crypto' comes before 'drivers' alphabetically. Fix this by calling tty_init() from chrdev_init(). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07frv: hide uncached_access() when pgprot_noncached is not #definedDavid Howells1-0/+2
Hide uncached_access() when pgprot_noncached is not #defined. This prevents the following warning: CC drivers/char/mem.o drivers/char/mem.c:229: warning: 'uncached_access' defined but not used Repairs d7d4d849b4e3acc405ec222884936800ffb26d48 ("drivers/char/mem.c: cleanups"). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07/dev/mem: allow rewindingEric Dumazet1-5/+0
commit dcefafb6 ("/dev/mem: dont allow seek to last page") inadvertently disabled rewinding on /dev/mem. This broke x86info for example. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07devmem: handle class_create() failureAnton Blanchard1-0/+3
I hit this when we had a bug in IDR for a few days. Basically sysfs would fail to create new inodes since it uses an IDR and therefore class_create would fail. While we are unlikely to see this fail we may as well handle it instead of oopsing. Signed-off-by: Anton Blanchard <anton@samba.org> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-13drivers/char/mem.c: cleanupsAndrew Morton1-102/+102
- fix switch statement layout - fix whitespace stuff - fix comment layout - remove unneeded inlining - use __weak - remove trailing whitespace - move uncached_access() inside `#ifndef __HAVE_PHYS_MEM_ACCESS_PROT' - it is otherwise unused. Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-13/dev/mem: dont allow seek to last pageWu Fengguang1-6/+13
So as to return a uniform error -EOVERFLOW instead of a random one: # kmem-seek 0xfffffffffffffff0 seek /dev/kmem: Device or resource busy # kmem-seek 0xfffffffffffffff1 seek /dev/kmem: Block device required Suggested by OGAWA Hirofumi. Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-02-03devmem: fix kmem write bug on memory holesWu Fengguang1-1/+1
write_kmem() used to assume vwrite() always return the full buffer length. However now vwrite() could return 0 to indicate memory hole. This creates a bug that "buf" is not advanced accordingly. Fix it to simply ignore the return value, hence the memory hole. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-02-03devmem: check vmalloc address on kmem read/writeKAMEZAWA Hiroyuki1-10/+18
Otherwise vmalloc_to_page() will BUG(). This also makes the kmem read/write implementation aligned with mem(4): "References to nonexistent locations cause errors to be returned." Here we return -ENXIO (inspired by Hugh) if no bytes have been transfered to/from user space, otherwise return partial read/write results. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15/dev/mem: remove redundant parameter from do_write_kmem()Wu Fengguang1-8/+6
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Avi Kivity <avi@qumranet.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15/dev/mem: remove the "written" variable in write_kmem()Wu Fengguang1-27/+22
Also rename "len" to "sz". No behavior change. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Avi Kivity <avi@qumranet.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15/dev/mem: make size_inside_page() logic straightWu Fengguang1-22/+12
Also convert more size_inside_page() users. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Avi Kivity <avi@qumranet.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15/dev/mem: cleanup unxlate_dev_mem_ptr() callsWu Fengguang1-8/+6
No behaviour change. [akpm@linux-foundation.org: cleanuplets] [akpm@linux-foundation.org: remove unused `ret'] Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Acked-by: Andi Kleen <ak@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15/dev/mem: introduce size_inside_page()Wu Fengguang1-41/+19
Introduce size_inside_page() to replace duplicate /dev/mem code. Also apply it to /dev/kmem, whose alignment logic was buggy. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Acked-by: Andi Kleen <ak@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15/dev/mem: remove redundant test on lenWu Fengguang1-8/+6
The len test in write_kmem() is always true, so can be reduced. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Acked-by: Andi Kleen <ak@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-10vfs: Implement proper O_SYNC semanticsChristoph Hellwig1-3/+3
While Linux provided an O_SYNC flag basically since day 1, it took until Linux 2.4.0-test12pre2 to actually get it implemented for filesystems, since that day we had generic_osync_around with only minor changes and the great "For now, when the user asks for O_SYNC, we'll actually give O_DSYNC" comment. This patch intends to actually give us real O_SYNC semantics in addition to the O_DSYNC semantics. After Jan's O_SYNC patches which are required before this patch it's actually surprisingly simple, we just need to figure out when to set the datasync flag to vfs_fsync_range and when not. This patch renames the existing O_SYNC flag to O_DSYNC while keeping it's numerical value to keep binary compatibility, and adds a new real O_SYNC flag. To guarantee backwards compatiblity it is defined as expanding to both the O_DSYNC and the new additional binary flag (__O_SYNC) to make sure we are backwards-compatible when compiled against the new headers. This also means that all places that don't care about the differences can just check O_DSYNC and get the right behaviour for O_SYNC, too - only places that actuall care need to check __O_SYNC in addition. Drivers and network filesystems have been updated in a fail safe way to always do the full sync magic if O_DSYNC is set. The few places setting O_SYNC for lower layers are kept that way for now to stay failsafe. We enforce that O_DSYNC is set when __O_SYNC is set early in the open path to make sure we always get these sane options. Note that parisc really screwed up their headers as they already define a O_DSYNC that has always been a no-op. We try to repair it by using it for the new O_DSYNC and redefinining O_SYNC to send both the traditional O_SYNC numerical value _and_ the O_DSYNC one. Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Grant Grundler <grundler@parisc-linux.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Dilger <adilger@sun.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jan Kara <jack@suse.cz>
2009-12-10Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits) tree-wide: fix misspelling of "definition" in comments reiserfs: fix misspelling of "journaled" doc: Fix a typo in slub.txt. inotify: remove superfluous return code check hdlc: spelling fix in find_pvc() comment doc: fix regulator docs cut-and-pasteism mtd: Fix comment in Kconfig doc: Fix IRQ chip docs tree-wide: fix assorted typos all over the place drivers/ata/libata-sff.c: comment spelling fixes fix typos/grammos in Documentation/edac.txt sysctl: add missing comments fs/debugfs/inode.c: fix comment typos sgivwfb: Make use of ARRAY_SIZE. sky2: fix sky2_link_down copy/paste comment error tree-wide: fix typos "couter" -> "counter" tree-wide: fix typos "offest" -> "offset" fix kerneldoc for set_irq_msi() spidev: fix double "of of" in comment comment typo fix: sybsystem -> subsystem ...
2009-12-04tree-wide: fix assorted typos all over the placeAndré Goddard Rosa1-1/+1
That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-10-14mem_class: Drop the bkl from memory_open()Frederic Weisbecker1-12/+5
The generic open callback for the mem class devices is "protected" by the bkl. Let's look at the datas manipulated inside memory_open: - inode and file: safe - the devlist: safe because it is constant - the memdev classes inside this array are safe too (constant) After we find out which memdev file operation we need to use, we call its open callback. Depending on the targeted memdev, we call either open_port() that doesn't manipulate any racy data (just a capable() check), or we call nothing. So it's safe to remove the big kernel lock there. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1255113062-5835-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-09-27const: mark struct vm_struct_operationsAlexey Dobriyan1-1/+1
* mark struct vm_area_struct::vm_ops as const * mark vm_ops in AGP code But leave TTM code alone, something is fishy there with global vm_ops being used. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24/dev/zero: avoid repeated access_ok() checksNikanth Karthikesan1-1/+1
In read_zero, we check for access_ok() once for the count bytes. It is unnecessarily checked again in clear_user. Use __clear_user, which does not check for access_ok(). Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-19Driver-Core: extend devnode callbacks to provide permissionsKay Sievers1-10/+19
This allows subsytems to provide devtmpfs with non-default permissions for the device node. Instead of the default mode of 0600, null, zero, random, urandom, full, tty, ptmx now have a mode of 0666, which allows non-privileged processes to access standard device nodes in case no other userspace process applies the expected permissions. This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15mem_class: fix bugJin Dongming1-2/+2
When I build and boot -next on fedora 10, I can not login anymore. When I input the user name and password, the system does not output any message and requires user to input the user name and password again and again. I find the patch which caused this problem with "GIT BISECT" command. And the patch is commit 7c4b7daa1878972ed0137c95f23569124bd6e2b1 "mem_class: use minor as index instead of searching the array". Though I don't know the real reason why user could not login, I confirmed the patch I made as following could resolve the problem on fedora 10. Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15mem_class: use minor as index instead of searching the arrayKay Sievers1-42/+40
Declare the device list with the minor numbers as the index, which saves us from searching for a matching list entry. Remove old devfs permissions declaration. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-11writeback: add name to backing_dev_infoJens Axboe1-0/+1
This enables us to track who does what and print info. Its main use is catching dirty inodes on the default_backing_dev_info, so we can fix that up. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-06-19drivers/char/mem.c: memory_open() cleanup: lookup minor device number from ↵Adriano dos Santos Fernandes1-70/+45
devlist memory_open() ignores devlist and does a switch for each item, duplicating code and conditional definitions. Clean it up by adding backing_dev_info to devlist and use it to lookup for the minor device. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Adriano dos Santos Fernandes <adrianosf@uol.com.br> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-10Make /dev/zero reads interruptible by signalsLinus Torvalds1-3/+2
This helps with bad latencies for large reads from /dev/zero, but might conceivably break some application that "knows" that a read of /dev/zero cannot return early. So do this early in the merge window to give us maximal test coverage, even if the patch is totally trivial. Obviously, no well-behaved application should ever depend on the read being uninterruptible, but hey, bugs happen. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-05drivers/char/mem.c: avoid OOM lockup during large reads from /dev/zeroSalman Qazi1-0/+3
While running 20 parallel instances of dd as follows: #!/bin/bash for i in `seq 1 20`; do dd if=/dev/zero of=/export/hda3/dd_$i bs=1073741824 count=1 & done wait on a 16G machine, we noticed that rather than just killing the processes, the entire kernel went down. Stracing dd reveals that it first does an mmap2, which makes 1GB worth of zero page mappings. Then it performs a read on those pages from /dev/zero, and finally it performs a write. The machine died during the reads. Looking at the code, it was noticed that /dev/zero's read operation had been changed by 557ed1fa2620dc119adb86b34c614e152a629a80 ("remove ZERO_PAGE") from giving zero page mappings to actually zeroing the page. The zeroing of the pages causes physical pages to be allocated to the process. But, when the process exhausts all the memory that it can, the kernel cannot kill it, as it is still in the kernel mode allocating more memory. Consequently, the kernel eventually crashes. To fix this, I propose that when a fatal signal is pending during /dev/zero read operation, we simply return and let the user process die. Signed-off-by: Salman Qazi <sqazi@google.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Modified error return and comment trivially. - Linus] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-10x86, PAT: Remove duplicate memtype reserve in devmem mmapSuresh Siddha1-27/+0
/dev/mem mmap code was doing memtype reserve/free for a while now. Recently we added memtype tracking in remap_pfn_range, and /dev/mem mmap uses it indirectly. So, we don't need seperate tracking in /dev/mem code any more. That means another ~100 lines of code removed :-). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> LKML-Reference: <20090409212709.085210000@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-07mm: make vread() and vwrite() declarationKOSAKI Motohiro1-3/+0
Sparse output following warnings. mm/vmalloc.c:1436:6: warning: symbol 'vread' was not declared. Should it be static? mm/vmalloc.c:1474:6: warning: symbol 'vwrite' was not declared. Should it be static? However, it is used by /dev/kmem. fixed here. Signed-off-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>
2008-10-16device create: char: convert device_create_drvdata to device_createGreg Kroah-Hartman1-3/+3
Now that device_create() has been audited, rename things back to the original call to be sane. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-24use generic_access_phys for /dev/mem mappingsRik van Riel1-1/+4
Use generic_access_phys as the access_process_vm access function for /dev/mem mappings. This makes it possible to debug the X server. [akpm@linux-foundation.org: repair all the architectures which broke] Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Benjamin Herrensmidt <benh@kernel.crashing.org> Cc: Dave Airlie <airlied@linux.ie> Cc: Hugh Dickins <hugh@veritas.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-22device create: char: convert device_create to device_create_drvdataGreg Kroah-Hartman1-3/+3
device_create() is race-prone, so use the race-free device_create_drvdata() instead as device_create() is going away. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-20Subject: devmem, x86: fix rename of CONFIG_NONPROMISC_DEVMEMIngo Molnar1-1/+1
From: Arjan van de Ven <arjan@infradead.org> Date: Sat, 19 Jul 2008 15:47:17 -0700 CONFIG_NONPROMISC_DEVMEM was a rather confusing name - but renaming it to CONFIG_PROMISC_DEVMEM causes problems on architectures that do not support this feature; this patch renames it to CONFIG_STRICT_DEVMEM, so that architectures can opt-in into it. ( the polarity of the option is still the same as it was originally; it needs to be for now to not break architectures that don't have the infastructure yet to support this feature) Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: "V.Radhakrishnan" <rk@atr-labs.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> ---
2008-07-18x86: rename CONFIG_NONPROMISC_DEVMEM to CONFIG_PROMISC_DEVMEMIngo Molnar1-1/+1
Linus observed: > The real bug is that we shouldn't have "double negatives", and > certainly not negative config options. Making that "promiscuous > /dev/mem" option a negated thing as a config option was bad. right ... lets rename this option. There should never be a negation in config options. [ that reminds me of CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER, but that is for another commit ;-) ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-21mem: cdev lock_kernel() pushdownJonathan Corbet1-2/+8
It's really hard to tell if this is necessary - lots of weird magic happens by way of map_devmem() Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2008-04-29make /dev/kmem a config optionArjan van de Ven1-0/+10
Make /dev/kmem a config option; /dev/kmem is VERY rarely used, and when used, it's generally for no good (rootkits tend to be the most common users). With this config option, users have the choice to disable /dev/kmem, saving some size as well. A patch to disable /dev/kmem has been in the Fedora and RHEL kernels for 4+ years now without any known problems or legit users of /dev/kmem. [akpm@linux-foundation.org: make CONFIG_DEVKMEM default to y] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-25x86: PAT use reserve free memtype in mmap of /dev/memvenkatesh.pallipadi@intel.com1-1/+34
Use reserve_memtype and free_memtype wrappers for /dev/mem mmaps. The memtype is slightly complicated here, given that we have to support existing X mappings. We fallback on UC_MINUS for that. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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