31 Mar, 2011
1 commit
-
Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: Lucas De Marchi
21 Feb, 2011
1 commit
-
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
Acked-by: Matt Mackall
Signed-off-by: Herbert Xu
17 Dec, 2010
1 commit
-
__this_cpu_inc can create a single instruction to do the same as
__get_cpu_var()++.Cc: Richard Kennedy
Cc: Matt Mackall
Acked-by: H. Peter Anvin
Signed-off-by: Christoph Lameter
Signed-off-by: Tejun Heo
15 Oct, 2010
1 commit
-
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(...)
{}
@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{}
@ 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)
{}
@ 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)
{}
@ 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
Cc: Julia Lawall
Cc: Christoph Hellwig
31 Jul, 2010
1 commit
-
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
Signed-off-by: Matt Mackall
Signed-off-by: Herbert Xu
20 May, 2010
1 commit
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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
Signed-off-by: Herbert Xu
04 Feb, 2010
1 commit
-
Some comments misspell "truly"; this fixes them. No code changes.
Signed-off-by: Adam Buchbinder
Signed-off-by: Jiri Kosina
02 Feb, 2010
2 commits
-
The previous changeset left behind an unused inode variable.
This patch removes it.Reported-by: Stephen Rothwell
Signed-off-by: Herbert Xu -
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
Signed-off-by: Herbert Xu
16 Dec, 2009
1 commit
-
Signed-off-by: Joe Perches
Acked-by: Matt Mackall
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Nov, 2009
1 commit
-
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
Cc: Ingo Molnar
Cc: Joe Perches
Signed-off-by: Eric W. Biederman
12 Nov, 2009
1 commit
-
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
Cc: Corey Minyard
Cc: Greg Kroah-Hartman
Cc: Matt Mackall
Cc: Herbert Xu
Cc: Neil Brown
Cc: "James E.J. Bottomley"
Acked-by: Clemens Ladisch for drivers/char/hpet.c
Signed-off-by: Eric W. Biederman
24 Sep, 2009
1 commit
-
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
Cc: David Howells
Cc: "Eric W. Biederman"
Cc: Al Viro
Cc: Ralf Baechle
Cc: Martin Schwidefsky
Cc: Ingo Molnar
Cc: "David S. Miller"
Cc: James Morris
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 Jun, 2009
1 commit
-
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
Acked-by: Matt Mackall
Signed-off-by: Herbert Xu
20 May, 2009
1 commit
-
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:2083and 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
Cc: Matt Mackall
Cc: Ingo Molnar
Signed-off-by: Linus Torvalds
08 May, 2009
1 commit
-
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
Signed-off-by: Linus Torvalds
03 Apr, 2009
1 commit
-
Align rekey_work. Even though it's infrequent, we may as well line it up.
Signed-off-by: Anton Blanchard
Acked-by: Matt Mackall
Cc: Theodore Ts'o
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jan, 2009
2 commits
-
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 1irq_desc is defined in linux/irq.h, so include it in the genirq case.
Signed-off-by: Yinghai Lu
Signed-off-by: Ingo Molnar -
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 genirqSigned-off-by: Yinghai Lu
Acked-by: Matt Mackall
Signed-off-by: Ingo Molnar
07 Jan, 2009
1 commit
-
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Jan, 2009
1 commit
-
those two functions only used in that C file
Signed-off-by: Yinghai Lu
Signed-off-by: Linus Torvalds
08 Dec, 2008
1 commit
-
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
Signed-off-by: Ingo Molnar
02 Nov, 2008
1 commit
-
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
Signed-off-by: Linus Torvalds
21 Oct, 2008
1 commit
-
…/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
...
17 Oct, 2008
1 commit
-
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
Acked-by: David S. Miller [ networking bits ]
Cc: Ralf Baechle
Cc: David Howells
Cc: Matt Mackall
Cc: "Eric W. Biederman"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Oct, 2008
5 commits
-
Revert the dynarray changes. They need more thought and polishing.
Signed-off-by: Thomas 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
-
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
Signed-off-by: Ingo Molnar -
Signed-off-by: Yinghai Lu
Signed-off-by: Ingo Molnar -
convert them to nr_irqs.
Signed-off-by: Yinghai Lu
Signed-off-by: Ingo Molnar
09 Oct, 2008
1 commit
-
* 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
Signed-off-by: Jens Axboe
03 Sep, 2008
1 commit
-
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
Date: Tue Apr 29 01:03:07 2008 -0700random: 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
Cc: Matt Mackall
Cc: Theodore Ts'o
Cc: [2.6.26.x]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Aug, 2008
1 commit
-
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
[ added missing EXPORT_SYMBOL_GPL ]
Signed-off-by: Patrick McHardy
Signed-off-by: David S. Miller
25 Jul, 2008
1 commit
-
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
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Apr, 2008
6 commits
-
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 randomnessWith it, you get:
$ ./async-random
Drained the pool
SIGIO
Found more randomness#include
#include
#include
#include
#includestatic 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
Signed-off-by: Matt Mackall
Cc: Theodore Ts'o
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- emphasize bits in the name
- make zero bits lock-free
- simplify logicSigned-off-by: Matt Mackall
Cc: Theodore Ts'o
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Cc: Theodore Ts'o
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Cc: Theodore Ts'o
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Cc: Theodore Ts'o
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- eliminate new_rotate
- move input_rotate masking
- simplify input_rotate update
- move input_rotate update to end of inner loop for readabilitySigned-off-by: Matt Mackall
Cc: Theodore Ts'o
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
