summaryrefslogtreecommitdiffstats
path: root/drivers/char/random.c
Commit message (Collapse)AuthorAgeFilesLines
* llseek: automatically add .llseek fopArnd Bergmann2010-10-151-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* random: Reorder struct entropy_store to remove padding on 64bits Richard Kennedy2010-07-311-1/+1
| | | | | | | | | | Re-order structure entropy_store to remove 8 bytes of padding on 64 bit builds, so shrinking this structure from 72 to 64 bytes and allowing it to fit into one cache line. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* random: simplify fips modeMatt Mackall2010-05-201-7/+3
| | | | | | | | Rather than dynamically allocate 10 bytes, move it to static allocation. This saves space and avoids the need for error checking. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* Fix misspellings of "truly" in comments.Adam Buchbinder2010-02-041-1/+1
| | | | | | | Some comments misspell "truly"; this fixes them. No code changes. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* random: Remove unused inode variableHerbert Xu2010-02-021-1/+0
| | | | | | | | The previous changeset left behind an unused inode variable. This patch removes it. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* random: drop weird m_time/a_time manipulationMatt Mackall2010-02-021-8/+0
| | | | | | | | | | | | No other driver does anything remotely like this that I know of except for the tty drivers, and I can't see any reason for random/urandom to do it. In fact, it's a (trivial, harmless) timing information leak. And obviously, it generates power- and flash-cycle wasting I/O, especially if combined with something like hwrngd. Also, it breaks ubifs's expectations. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* random.c: use %pU to print UUIDsJoe Perches2009-12-151-7/+3
| | | | | | | Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl: Drop & in front of every proc_handler.Eric W. Biederman2009-11-181-6/+6
| | | | | | | | | | | For consistency drop & in front of every proc_handler. Explicity taking the address is unnecessary and it prevents optimizations like stubbing the proc_handlers to NULL. Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Joe Perches <joe@perches.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl drivers: Remove dead binary sysctl supportEric W. Biederman2009-11-121-41/+1
| | | | | | | | | | | | | | | | Now that sys_sysctl is a wrapper around /proc/sys all of the binary sysctl support elsewhere in the tree is dead code. Cc: Jens Axboe <axboe@kernel.dk> Cc: Corey Minyard <minyard@acm.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Neil Brown <neilb@suse.de> Cc: "James E.J. Bottomley" <James.Bottomley@suse.de> Acked-by: Clemens Ladisch <clemens@ladisch.de> for drivers/char/hpet.c Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: remove "struct file *" argument of ->proc_handlerAlexey Dobriyan2009-09-241-2/+2
| | | | | | | | | | | | | | | | | | | | | It's unused. It isn't needed -- read or write flag is already passed and sysctl shouldn't care about the rest. It _was_ used in two places at arch/frv for some reason. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: Add optional continuous repetition test to entropy store based rngsNeil Horman2009-06-181-0/+14
| | | | | | | | | | | | | | | | FIPS-140 requires that all random number generators implement continuous self tests in which each extracted block of data is compared against the last block for repetition. The ansi_cprng implements such a test, but it would be nice if the hw rng's did the same thing. Obviously its not something thats always needed, but it seems like it would be a nice feature to have on occasion. I've written the below patch which allows individual entropy stores to be flagged as desiring a continuous test to be run on them as is extracted. By default this option is off, but is enabled in the event that fips mode is selected during bootup. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* Avoid ICE in get_random_int() with gcc-3.4.5Linus Torvalds2009-05-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Martin Knoblauch reports that trying to build 2.6.30-rc6-git3 with RHEL4.3 userspace (gcc (GCC) 3.4.5 20051201 (Red Hat 3.4.5-2)) causes an internal compiler error (ICE): drivers/char/random.c: In function `get_random_int': drivers/char/random.c:1672: error: unrecognizable insn: (insn 202 148 150 0 /scratch/build/linux-2.6.30-rc6-git3/arch/x86/include/asm/tsc.h:23 (set (reg:SI 0 ax [91]) (subreg:SI (plus:DI (plus:DI (reg:DI 0 ax [88]) (subreg:DI (reg:SI 6 bp) 0)) (const_int -4 [0xfffffffffffffffc])) 0)) -1 (nil) (nil)) drivers/char/random.c:1672: internal compiler error: in extract_insn, at recog.c:2083 and after some debugging it turns out that it's due to the code trying to figure out the rough value of the current stack pointer by taking an address of an uninitialized variable and casting that to an integer. This is clearly a compiler bug, but it's not worth fighting - while the current stack kernel pointer might be somewhat hard to predict in user space, it's also not generally going to change for a lot of the call chains for a particular process. So just drop it, and mumble some incoherent curses at the compiler. Tested-by: Martin Knoblauch <spamtrap@knobisoft.de> Cc: Matt Mackall <mpm@selenic.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: make get_random_int() more randomLinus Torvalds2009-05-071-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's a really simple patch that basically just open-codes the current "secure_ip_id()" call, but when open-coding it we now use a _static_ hashing area, so that it gets updated every time. And to make sure somebody can't just start from the same original seed of all-zeroes, and then do the "half_md4_transform()" over and over until they get the same sequence as the kernel has, each iteration also mixes in the same old "current->pid + jiffies" we used - so we should now have a regular strong pseudo-number generator, but we also have one that doesn't have a single seed. Note: the "pid + jiffies" is just meant to be a tiny tiny bit of noise. It has no real meaning. It could be anything. I just picked the previous seed, it's just that now we keep the state in between calls and that will feed into the next result, and that should make all the difference. I made that hash be a per-cpu data just to avoid cache-line ping-pong: having multiple CPU's write to the same data would be fine for randomness, and add yet another layer of chaos to it, but since get_random_int() is supposed to be a fast interface I did it that way instead. I considered using "__raw_get_cpu_var()" to avoid any preemption overhead while still getting the hash be _mostly_ ping-pong free, but in the end good taste won out. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: align rekey_work's timerAnton Blanchard2009-04-021-1/+2
| | | | | | | | | | Align rekey_work. Even though it's infrequent, we may as well line it up. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sparseirq: fix build with unknown irq_desc structYinghai Lu2009-01-111-0/+4
| | | | | | | | | | | | | | | | | Ingo Molnar wrote: > > tip/kernel/fork.c: In function 'copy_signal': > tip/kernel/fork.c:825: warning: unused variable 'ret' > tip/drivers/char/random.c: In function 'get_timer_rand_state': > tip/drivers/char/random.c:584: error: dereferencing pointer to incomplete type > tip/drivers/char/random.c: In function 'set_timer_rand_state': > tip/drivers/char/random.c:594: error: dereferencing pointer to incomplete type > make[3]: *** [drivers/char/random.o] Error 1 irq_desc is defined in linux/irq.h, so include it in the genirq case. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sparseirq: make some func to be used with genirqYinghai Lu2009-01-111-1/+1
| | | | | | | | | | | Impact: clean up sparseirq fallout on random.c Ingo suggested to change some ifdef from SPARSE_IRQ to GENERIC_HARDIRQS so we could some #ifdef later if all arch support genirq Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* random: don't try to look at entropy_count outside the lockMatt Mackall2009-01-061-3/+2
| | | | | | | | | | | | | | | | | | As a non-atomic value, it's only safe to look at entropy_count when the pool lock is held, so we move the BUG_ON inside the lock for correctness. Also remove the spurious comment. It's ok for entropy_count to temporarily exceed POOLBITS so long as it's left in a consistent state when the lock is released. This is a more correct, simple, and idiomatic fix for the bug in 8b76f46a2db. I've left the reorderings introduced by that patch in place as they're harmless, even though they don't properly deal with potential atomicity issues. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sparseirq: move set/get_timer_rand_state back to .cYinghai Lu2009-01-031-6/+34
| | | | | | | those two functions only used in that C file Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sparse irq_desc[] array: core kernel and x86 changesYinghai Lu2008-12-081-17/+5
| | | | | | | | | | | | | | | | | | | | | Impact: new feature Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with NR_CPUS set to large values. The goal is to be able to scale up to much larger NR_IRQS value without impacting the (important) common case. To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of irq_desc pointers. When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc, this also makes the IRQ descriptors NUMA-local (to the site that calls request_irq()). This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now uses desc->chip_data for x86 to store irq_cfg. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* saner FASYNC handling on file closeAl Viro2008-11-011-7/+0
| | | | | | | | | | | | | | As it is, all instances of ->release() for files that have ->fasync() need to remember to evict file from fasync lists; forgetting that creates a hole and we actually have a bunch that *does* forget. So let's keep our lives simple - let __fput() check FASYNC in file->f_flags and call ->fasync() there if it's been set. And lose that crap in ->release() instances - leaving it there is still valid, but we don't have to bother anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'genirq-v28-for-linus' of ↵Linus Torvalds2008-10-201-5/+31
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip This merges branches irq/genirq, irq/sparseirq-v4, timers/hpet-percpu and x86/uv. The sparseirq branch is just preliminary groundwork: no sparse IRQs are actually implemented by this tree anymore - just the new APIs are added while keeping the old way intact as well (the new APIs map 1:1 to irq_desc[]). The 'real' sparse IRQ support will then be a relatively small patch ontop of this - with a v2.6.29 merge target. * 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (178 commits) genirq: improve include files intr_remapping: fix typo io_apic: make irq_mis_count available on 64-bit too genirq: fix name space collisions of nr_irqs in arch/* genirq: fix name space collision of nr_irqs in autoprobe.c genirq: use iterators for irq_desc loops proc: fixup irq iterator genirq: add reverse iterator for irq_desc x86: move ack_bad_irq() to irq.c x86: unify show_interrupts() and proc helpers x86: cleanup show_interrupts genirq: cleanup the sparseirq modifications genirq: remove artifacts from sparseirq removal genirq: revert dynarray genirq: remove irq_to_desc_alloc genirq: remove sparse irq code genirq: use inline function for irq_to_desc genirq: consolidate nr_irqs and for_each_irq_desc() x86: remove sparse irq from Kconfig genirq: define nr_irqs for architectures with GENERIC_HARDIRQS=n ...
| * genirq: revert dynarrayThomas Gleixner2008-10-161-5/+0
| | | | | | | | | | | | Revert the dynarray changes. They need more thought and polishing. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * genirq: remove sparse irq codeThomas Gleixner2008-10-161-31/+0
| | | | | | | | | | | | | | This code is not ready, but we need to rip it out instead of rebasing as we would lose the APIC/IO_APIC unification otherwise. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * x86: put timer_rand_state pointer into irq_descYinghai Lu2008-10-161-5/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | irq_timer_state[] is a NR_IRQS sized array that is a side-by array to the real irq_desc[] array. Integrate that field into the (now dynamic) irq_desc dynamic array and save some RAM. v2: keep the old way to support arch not support irq_desc Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * irqs: make irq_timer_state to use dyn_arrayYinghai Lu2008-10-161-0/+6
| | | | | | | | | | Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * drivers/char: use nr_irqsYinghai Lu2008-10-161-2/+2
| | | | | | | | | | | | | | convert them to nr_irqs. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sysctl: simplify ->strategyAlexey Dobriyan2008-10-161-1/+1
|/ | | | | | | | | | | | | | | | name and nlen parameters passed to ->strategy hook are unused, remove them. In general ->strategy hook should know what it's doing, and don't do something tricky for which, say, pointer to original userspace array may be needed (name). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> [ networking bits ] Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Matt Mackall <mpm@selenic.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: don't depend on consecutive minor spaceTejun Heo2008-10-091-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | * Implement disk_devt() and part_devt() and use them to directly access devt instead of computing it from ->major and ->first_minor. Note that all references to ->major and ->first_minor outside of block layer is used to determine devt of the disk (the part0) and as ->major and ->first_minor will continue to represent devt for the disk, converting these users aren't strictly necessary. However, convert them for consistency. * Implement disk_max_parts() to avoid directly deferencing genhd->minors. * Update bdget_disk() such that it doesn't assume consecutive minor space. * Move devt computation from register_disk() to add_disk() and make it the only one (all other usages use the initially determined value). These changes clean up the code and will help disk->part dereference fix and extended block device numbers. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* drivers/char/random.c: fix a race which can lead to a bogus BUG()Andrew Morton2008-09-021-9/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a bug reported by and diagnosed by Aaron Straus. This is a regression intruduced into 2.6.26 by commit adc782dae6c4c0f6fb679a48a544cfbcd79ae3dc Author: Matt Mackall <mpm@selenic.com> Date: Tue Apr 29 01:03:07 2008 -0700 random: simplify and rename credit_entropy_store credit_entropy_bits() does: spin_lock_irqsave(&r->lock, flags); ... if (r->entropy_count > r->poolinfo->POOLBITS) r->entropy_count = r->poolinfo->POOLBITS; so there is a time window in which this BUG_ON(): static size_t account(struct entropy_store *r, size_t nbytes, int min, int reserved) { unsigned long flags; BUG_ON(r->entropy_count > r->poolinfo->POOLBITS); /* Hold lock while accounting */ spin_lock_irqsave(&r->lock, flags); can trigger. We could fix this by moving the assertion inside the lock, but it seems safer and saner to revert to the old behaviour wherein entropy_store.entropy_count at no time exceeds entropy_store.poolinfo->POOLBITS. Reported-by: Aaron Straus <aaron@merfinllc.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: <stable@kernel.org> [2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* nf_nat: use secure_ipv4_port_ephemeral() for NAT port randomizationStephen Hemminger2008-08-181-0/+1
| | | | | | | | | | | | | Use incoming network tuple as seed for NAT port randomization. This avoids concerns of leaking net_random() bits, and also gives better port distribution. Don't have NAT server, compile tested only. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> [ added missing EXPORT_SYMBOL_GPL ] Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architecturesAndrea Righi2008-07-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit boundary. For example: u64 val = PAGE_ALIGN(size); always returns a value < 4GB even if size is greater than 4GB. The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for example): #define PAGE_SHIFT 12 #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) #define PAGE_MASK (~(PAGE_SIZE-1)) ... #define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK) The "~" is performed on a 32-bit value, so everything in "and" with PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary. Using the ALIGN() macro seems to be the right way, because it uses typeof(addr) for the mask. Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in include/linux/mm.h. See also lkml discussion: http://lkml.org/lkml/2008/6/11/237 [akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c] [akpm@linux-foundation.org: fix v850] [akpm@linux-foundation.org: fix powerpc] [akpm@linux-foundation.org: fix arm] [akpm@linux-foundation.org: fix mips] [akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c] [akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c] [akpm@linux-foundation.org: fix powerpc] Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: add async notification support to /dev/randomJeff Dike2008-04-291-2/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add async notification support to /dev/random. A little test case is below. Without this patch, you get: $ ./async-random Drained the pool Found more randomness With it, you get: $ ./async-random Drained the pool SIGIO Found more randomness #include <stdio.h> #include <stdlib.h> #include <signal.h> #include <errno.h> #include <fcntl.h> static void handler(int sig) { printf("SIGIO\n"); } int main(int argc, char **argv) { int fd, n, err, flags; if(signal(SIGIO, handler) < 0){ perror("setting SIGIO handler"); exit(1); } fd = open("/dev/random", O_RDONLY); if(fd < 0){ perror("open"); exit(1); } flags = fcntl(fd, F_GETFL); if (flags < 0){ perror("getting flags"); exit(1); } flags |= O_NONBLOCK; if (fcntl(fd, F_SETFL, flags) < 0){ perror("setting flags"); exit(1); } while((err = read(fd, &n, sizeof(n))) > 0) ; if(err == 0){ printf("random returned 0\n"); exit(1); } else if(errno != EAGAIN){ perror("read"); exit(1); } flags |= O_ASYNC; if (fcntl(fd, F_SETFL, flags) < 0){ perror("setting flags"); exit(1); } if (fcntl(fd, F_SETOWN, getpid()) < 0) { perror("Setting SIGIO"); exit(1); } printf("Drained the pool\n"); read(fd, &n, sizeof(n)); printf("Found more randomness\n"); return(0); } Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: simplify and rename credit_entropy_storeMatt Mackall2008-04-291-17/+15
| | | | | | | | | | | - emphasize bits in the name - make zero bits lock-free - simplify logic Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: make mixing interface byte-orientedMatt Mackall2008-04-291-18/+19
| | | | | | | | | | | | | | | | | | | | Switch add_entropy_words to a byte-oriented interface, eliminating numerous casts and byte/word size rounding issues. This also reduces the overall bit/byte/word confusion in this code. We now mix a byte at a time into the word-based pool. This takes four times as many iterations, but should be negligible compared to hashing overhead. This also increases our pool churn, which adds some depth against some theoretical failure modes. The function name is changed to emphasize pool mixing and deemphasize entropy (the samples mixed in may not contain any). extract is added to the core function to make it clear that it extracts from the pool. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: simplify add_ptr logicMatt Mackall2008-04-291-11/+10
| | | | | | | | | | | | The add_ptr variable wasn't used in a sensible way, use only i instead. i got reused later for a different purpose, use j instead. While we're here, put tap0 first in the tap list and add a comment. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: remove some prefetch logicMatt Mackall2008-04-291-6/+2
| | | | | | | | | | | | | | The urandom output pool (ie the fast path) fits in one cacheline, so this is pretty unnecessary. Further, the output path has already fetched the entire pool to hash it before calling in here. (This was the only user of prefetch_range in the kernel, and it passed in words rather than bytes!) Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: eliminate redundant new_rotate variableMatt Mackall2008-04-291-12/+10
| | | | | | | | | | | | - eliminate new_rotate - move input_rotate masking - simplify input_rotate update - move input_rotate update to end of inner loop for readability Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: remove cacheline alignment for locksMatt Mackall2008-04-291-2/+2
| | | | | | | | | | Earlier changes greatly reduce the number of times we grab the lock per output byte, so we shouldn't need this particular hack any more. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: make backtracking attacks harderMatt Mackall2008-04-291-19/+17
| | | | | | | | | | | | | | | | | At each extraction, we change (poolbits / 16) + 32 bits in the pool, or 96 bits in the case of the secondary pools. Thus, a brute-force backtracking attack on the pool state is less difficult than breaking the hash. In certain cases, this difficulty may be is reduced to 2^64 iterations. Instead, hash the entire pool in one go, then feedback the whole hash (160 bits) in one go. This will make backtracking at least as hard as inverting the hash. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: improve variable naming, clear extract bufferMatt Mackall2008-04-291-11/+13
| | | | | | | | | | | - split the SHA variables apart into hash and workspace - rename data to extract - wipe extract and workspace after hashing Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: reuse rand_initializeMatt Mackall2008-04-291-4/+2
| | | | | | | Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: use unlocked_ioctlMatt Mackall2008-04-291-6/+5
| | | | | | | | | No locking actually needed. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: consolidate wakeup logicMatt Mackall2008-04-291-16/+4
| | | | | | | Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* random: clean up checkpatch complaintsMatt Mackall2008-04-291-45/+35
| | | | | | | Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/char/random.c:write_pool() cond_resched() neededMatt Mackall2008-02-061-0/+1
| | | | | | | | | | Reduce latency for large writes to /dev/[u]random Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Sami Farin <safari-kernel@safari.iki.fi> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* unexport add_disk_randomnessAdrian Bunk2008-02-011-2/+0
| | | | | | | | This patch removes the no longer used EXPORT_SYMBOL(add_disk_randomness). Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* [NET] random : secure_tcp_sequence_number should not assume CONFIG_KTIME_SCALAREric Dumazet2007-11-131-3/+3
| | | | | | | | | | | | | | | | All 32 bits machines but i386 dont have CONFIG_KTIME_SCALAR. On these machines, ktime.tv64 is more than 4 times the (correct) result given by ktime_to_ns() Again on these machines, using ktime_get_real().tv64 >> 6 give a 32bits rollover every 64 seconds, which is not wanted (less than the 120 s MSL) Using ktime_to_ns() is the portable way to get nsecs from a ktime, and have correct code. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sparse pointer use of zero as nullStephen Hemminger2007-10-181-1/+1
| | | | | | | | | | | | | | | | | Get rid of sparse related warnings from places that use integer as NULL pointer. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Cc: Andi Kleen <ak@suse.de> Cc: Jeff Garzik <jeff@garzik.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Ian Kent <raven@themaw.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [TCP]: secure_tcp_sequence_number() should not use a too fast clockEric Dumazet2007-10-011-4/+6
| | | | | | | | | | | | | | | | | TCP V4 sequence numbers are 32bits, and RFC 793 assumed a 250 KHz clock. In order to follow network speed increase, we can use a faster clock, but we should limit this clock so that the delay between two rollovers is greater than MSL (TCP Maximum Segment Lifetime : 2 minutes) Choosing a 64 nsec clock should be OK, since the rollovers occur every 274 seconds. Problem spotted by Denys Fedoryshchenko [ This bug was introduced by f85958151900f9d30fa5ff941b0ce71eaa45a7de ] Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* random: fix bound check ordering (CVE-2007-3105)Matt Mackall2007-07-191-2/+7
| | | | | | | | | | | | | | If root raised the default wakeup threshold over the size of the output pool, the pool transfer function could overflow the stack with RNG bytes, causing a DoS or potential privilege escalation. (Bug reported by the PaX Team <pageexec@freemail.hu>) Cc: Theodore Tso <tytso@mit.edu> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
OpenPOWER on IntegriCloud