summaryrefslogtreecommitdiff
path: root/drivers/char/random.c
AgeCommit message (Collapse)Author
2013-05-30random: fix accounting race condition with lockless irq entropy_count updateJiri Kosina
commit 10b3a32d292c21ea5b3ad5ca5975e88bb20b8d68 upstream. Commit 902c098a3663 ("random: use lockless techniques in the interrupt path") turned IRQ path from being spinlock protected into lockless cmpxchg-retry update. That commit removed r->lock serialization between crediting entropy bits from IRQ context and accounting when extracting entropy on userspace read path, but didn't turn the r->entropy_count reads/updates in account() to use cmpxchg as well. It has been observed, that under certain circumstances this leads to read() on /dev/urandom to return 0 (EOF), as r->entropy_count gets corrupted and becomes negative, which in turn results in propagating 0 all the way from account() to the actual read() call. Convert the accounting code to be the proper lockless counterpart of what has been partially done by 902c098a3663. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-12random: Add comment to random_initialize()Tony Luck
commit cbc96b7594b5691d61eba2db8b2ea723645be9ca upstream. Many platforms have per-machine instance data (serial numbers, asset tags, etc.) squirreled away in areas that are accessed during early system bringup. Mixing this data into the random pools has a very high value in providing better random data, so we should allow (and even encourage) architecture code to call add_device_randomness() from the setup_arch() paths. However, this limits our options for internal structure of the random driver since random_initialize() is not called until long after setup_arch(). Add a big fat comment to rand_initialize() spelling out this requirement. Suggested-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-12drivers/char/random.c: fix boot id uniqueness raceMathieu Desnoyers
commit 44e4360fa3384850d65dd36fb4e6e5f2f112709b upstream. /proc/sys/kernel/random/boot_id can be read concurrently by userspace processes. If two (or more) user-space processes concurrently read boot_id when sysctl_bootid is not yet assigned, a race can occur making boot_id differ between the reads. Because the whole point of the boot id is to be unique across a kernel execution, fix this by protecting this operation with a spinlock. Given that this operation is not frequently used, hitting the spinlock on each call should not be an issue. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-10random: mix in architectural randomness in extract_buf()H. Peter Anvin
commit d2e7c96af1e54b507ae2a6a7dd2baf588417a7e5 upstream. Mix in any architectural randomness in extract_buf() instead of xfer_secondary_buf(). This allows us to mix in more architectural randomness, and it also makes xfer_secondary_buf() faster, moving a tiny bit of additional CPU overhead to process which is extracting the randomness. [ Commit description modified by tytso to remove an extended advertisement for the RDRAND instruction. ] Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: DJ Johnston <dj.johnston@intel.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-10random: add new get_random_bytes_arch() functionTheodore Ts'o
commit c2557a303ab6712bb6e09447df828c557c710ac9 upstream. Create a new function, get_random_bytes_arch() which will use the architecture-specific hardware random number generator if it is present. Change get_random_bytes() to not use the HW RNG, even if it is avaiable. The reason for this is that the hw random number generator is fast (if it is present), but it requires that we trust the hardware manufacturer to have not put in a back door. (For example, an increasing counter encrypted by an AES key known to the NSA.) It's unlikely that Intel (for example) was paid off by the US Government to do this, but it's impossible for them to prove otherwise
2012-08-10random: use the arch-specific rng in xfer_secondary_poolTheodore Ts'o
commit e6d4947b12e8ad947add1032dd754803c6004824 upstream. If the CPU supports a hardware random number generator, use it in xfer_secondary_pool(), where it will significantly improve things and where we can afford it. Also, remove the use of the arch-specific rng in add_timer_randomness(), since the call is significantly slower than get_cycles(), and we're much better off using it in xfer_secondary_pool() anyway. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-10random: create add_device_randomness() interfaceLinus Torvalds
commit a2080a67abe9e314f9e9c2cc3a4a176e8a8f8793 upstream. Add a new interface, add_device_randomness() for adding data to the random pool that is likely to differ between two devices (or possibly even per boot). This would be things like MAC addresses or serial numbers, or the read-out of the RTC. This does *not* add any actual entropy to the pool, but it initializes the pool to different values for devices that might otherwise be identical and have very little entropy available to them (particularly common in the embedded world). [ Modified by tytso to mix in a timestamp, since there may be some variability caused by the time needed to detect/configure the hardware in question. ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-10random: use lockless techniques in the interrupt pathTheodore Ts'o
commit 902c098a3663de3fa18639efbb71b6080f0bcd3c upstream. The real-time Linux folks don't like add_interrupt_randomness() taking a spinlock since it is called in the low-level interrupt routine. This also allows us to reduce the overhead in the fast path, for the random driver, which is the interrupt collection path. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-10random: make 'add_interrupt_randomness()' do something saneTheodore Ts'o
commit 775f4b297b780601e61787b766f306ed3e1d23eb upstream. We've been moving away from add_interrupt_randomness() for various reasons: it's too expensive to do on every interrupt, and flooding the CPU with interrupts could theoretically cause bogus floods of entropy from a somewhat externally controllable source. This solves both problems by limiting the actual randomness addition to just once a second or after 64 interrupts, whicever comes first. During that time, the interrupt cycle data is buffered up in a per-cpu pool. Also, we make sure the the nonblocking pool used by urandom is initialized before we start feeding the normal input pool. This assures that /dev/urandom is returning unpredictable data as soon as possible. (Based on an original patch by Linus, but significantly modified by tytso.) Tested-by: Eric Wustrow <ewust@umich.edu> Reported-by: Eric Wustrow <ewust@umich.edu> Reported-by: Nadia Heninger <nadiah@cs.ucsd.edu> Reported-by: Zakir Durumeric <zakir@umich.edu> Reported-by: J. Alex Halderman <jhalderm@umich.edu>. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-10random: Adjust the number of loops when initializingH. Peter Anvin
commit 2dac8e54f988ab58525505d7ef982493374433c3 upstream. When we are initializing using arch_get_random_long() we only need to loop enough times to touch all the bytes in the buffer; using poolwords for that does twice the number of operations necessary on a 64-bit machine, since in the random number generator code "word" means 32 bits. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Link: http://lkml.kernel.org/r/1324589281-31931-1-git-send-email-tytso@mit.edu Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-10random: Use arch-specific RNG to initialize the entropy storeTheodore Ts'o
commit 3e88bdff1c65145f7ba297ccec69c774afe4c785 upstream. If there is an architecture-specific random number generator (such as RDRAND for Intel architectures), use it to initialize /dev/random's entropy stores. Even in the worst case, if RDRAND is something like AES(NSA_KEY, counter++), it won't hurt, and it will definitely help against any other adversaries. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Link: http://lkml.kernel.org/r/1324589281-31931-1-git-send-email-tytso@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-10random: Use arch_get_random_int instead of cycle counter if availLinus Torvalds
commit cf833d0b9937874b50ef2867c4e8badfd64948ce upstream. We still don't use rdrand in /dev/random, which just seems stupid. We accept the *cycle*counter* as a random input, but we don't accept rdrand? That's just broken. Sure, people can do things in user space (write to /dev/random, use rdrand in addition to /dev/random themselves etc etc), but that *still* seems to be a particularly stupid reason for saying "we shouldn't bother to try to do better in /dev/random". And even if somebody really doesn't trust rdrand as a source of random bytes, it seems singularly stupid to trust the cycle counter *more*. So I'd suggest the attached patch. I'm not going to even bother arguing that we should add more bits to the entropy estimate, because that's not the point - I don't care if /dev/random fills up slowly or not, I think it's just stupid to not use the bits we can get from rdrand and mix them into the strong randomness pool. Link: http://lkml.kernel.org/r/CA%2B55aFwn59N1=m651QAyTy-1gO1noGbK18zwKDwvwqnravA84A@mail.gmail.com Acked-by: "David S. Miller" <davem@davemloft.net> Acked-by: "Theodore Ts'o" <tytso@mit.edu> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Cc: Matt Mackall <mpm@selenic.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2011-11-17fix typo/thinko in get_random_bytes()Luck, Tony
If there is an architecture-specific random number generator we use it to acquire randomness one "long" at a time. We should put these random words into consecutive words in the result buffer - not just overwrite the first word again and again. Signed-off-by: Tony Luck <tony.luck@intel.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-28Merge branch 'x86-rdrand-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'x86-rdrand-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, random: Verify RDRAND functionality and allow it to be disabled x86, random: Architectural inlines to get random integers with RDRAND random: Add support for architectural random hooks Fix up trivial conflicts in drivers/char/random.c: the architectural random hooks touched "get_random_int()" that was simplified to use MD5 and not do the keyptr thing any more (see commit 6e5714eaf77d: "net: Compute protocol sequence numbers and fragment IDs using MD5").
2011-08-06net: Compute protocol sequence numbers and fragment IDs using MD5.David S. Miller
Computers have become a lot faster since we compromised on the partial MD4 hash which we use currently for performance reasons. MD5 is a much safer choice, and is inline with both RFC1948 and other ISS generators (OpenBSD, Solaris, etc.) Furthermore, only having 24-bits of the sequence number be truly unpredictable is a very serious limitation. So the periodic regeneration and 8-bit counter have been removed. We compute and use a full 32-bit sequence number. For ipv6, DCCP was found to use a 32-bit truncated initial sequence number (it needs 43-bits) and that is fixed here as well. Reported-by: Dan Kaminsky <dan@doxpara.com> Tested-by: Willy Tarreau <w@1wt.eu> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-31random: Add support for architectural random hooksH. Peter Anvin
Add support for architecture-specific hooks into the kernel-directed random number generator interfaces. This patchset does not use the architecture random number generator interfaces for the userspace-directed interfaces (/dev/random and /dev/urandom), thus eliminating the need to distinguish between them based on a pool pointer. Changes in version 3: - Moved the hooks from extract_entropy() to get_random_bytes(). - Changes the hooks to inlines. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "Theodore Ts'o" <tytso@mit.edu>
2011-07-21ipv6: make fragment identifications less predictableEric Dumazet
IPv6 fragment identification generation is way beyond what we use for IPv4 : It uses a single generator. Its not scalable and allows DOS attacks. Now inetpeer is IPv6 aware, we can use it to provide a more secure and scalable frag ident generator (per destination, instead of system wide) This patch : 1) defines a new secure_ipv6_id() helper 2) extends inet_getid() to provide 32bit results 3) extends ipv6_select_ident() with a new dest parameter Reported-by: Fernando Gont <fernando@gont.com.ar> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-02-21random: update interface comments to reflect realityJarod Wilson
At present, the comment header in random.c makes no mention of add_disk_randomness, and instead, suggests that disk activity adds to the random pool by way of add_interrupt_randomness, which appears to not have been the case since sometime prior to the existence of git, and even prior to bitkeeper. Didn't look any further back. At least, as far as I can tell, there are no storage drivers setting IRQF_SAMPLE_RANDOM, which is a requirement for add_interrupt_randomness to trigger, so the only way for a disk to contribute entropy is by way of add_disk_randomness. Update comments accordingly, complete with special mention about solid state drives being a crappy source of entropy (see e2e1a148bc for reference). Signed-off-by: Jarod Wilson <jarod@redhat.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-12-17random: Use this_cpu_inc_returnChristoph Lameter
__this_cpu_inc can create a single instruction to do the same as __get_cpu_var()++. Cc: Richard Kennedy <richard@rsk.demon.co.uk> Cc: Matt Mackall <mpm@selenic.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
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>
2010-07-31random: Reorder struct entropy_store to remove padding on 64bits Richard Kennedy
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>
2010-05-20random: simplify fips modeMatt Mackall
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>
2010-02-04Fix misspellings of "truly" in comments.Adam Buchbinder
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>
2010-02-02random: Remove unused inode variableHerbert Xu
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>
2010-02-02random: drop weird m_time/a_time manipulationMatt Mackall
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>
2009-12-15random.c: use %pU to print UUIDsJoe Perches
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>
2009-11-18sysctl: Drop & in front of every proc_handler.Eric W. Biederman
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>
2009-11-12sysctl drivers: Remove dead binary sysctl supportEric W. Biederman
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>
2009-09-24sysctl: remove "struct file *" argument of ->proc_handlerAlexey Dobriyan
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>
2009-06-18random: Add optional continuous repetition test to entropy store based rngsNeil Horman
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>
2009-05-19Avoid ICE in get_random_int() with gcc-3.4.5Linus Torvalds
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>
2009-05-07random: make get_random_int() more randomLinus Torvalds
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>
2009-04-02random: align rekey_work's timerAnton Blanchard
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>
2009-01-11sparseirq: fix build with unknown irq_desc structYinghai Lu
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>
2009-01-11sparseirq: make some func to be used with genirqYinghai Lu
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>
2009-01-06random: don't try to look at entropy_count outside the lockMatt Mackall
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>
2009-01-03sparseirq: move set/get_timer_rand_state back to .cYinghai Lu
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>
2008-12-08sparse irq_desc[] array: core kernel and x86 changesYinghai Lu
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>
2008-11-01saner FASYNC handling on file closeAl Viro
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>
2008-10-20Merge branch 'genirq-v28-for-linus' of ↵Linus Torvalds
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 ...
2008-10-16sysctl: simplify ->strategyAlexey Dobriyan
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>
2008-10-16genirq: revert dynarrayThomas Gleixner
Revert the dynarray changes. They need more thought and polishing. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-16genirq: remove sparse irq codeThomas Gleixner
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>
2008-10-16x86: put timer_rand_state pointer into irq_descYinghai Lu
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>
2008-10-16irqs: make irq_timer_state to use dyn_arrayYinghai Lu
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16drivers/char: use nr_irqsYinghai Lu
convert them to nr_irqs. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-09block: don't depend on consecutive minor spaceTejun Heo
* 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>
2008-09-02drivers/char/random.c: fix a race which can lead to a bogus BUG()Andrew Morton
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>
2008-08-18nf_nat: use secure_ipv4_port_ephemeral() for NAT port randomizationStephen Hemminger
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>