The patch titled
random: add async notification support to /dev/random
has been added to the -mm tree. Its filename is
random-add-async-notification-support-to-dev-random.patch
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------------------------------------------------------
Subject: random: add async notification support to /dev/random
From: Jeff Dike <[EMAIL PROTECTED]>
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 <[EMAIL PROTECTED]>
Signed-off-by: Matt Mackall <[EMAIL PROTECTED]>
Cc: Theodore Ts'o <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
drivers/char/random.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)
diff -puN
drivers/char/random.c~random-add-async-notification-support-to-dev-random
drivers/char/random.c
--- a/drivers/char/random.c~random-add-async-notification-support-to-dev-random
+++ a/drivers/char/random.c
@@ -370,6 +370,7 @@ static struct poolinfo {
*/
static DECLARE_WAIT_QUEUE_HEAD(random_read_wait);
static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);
+static struct fasync_struct *fasync;
#if 0
static int debug;
@@ -533,8 +534,11 @@ static void credit_entropy_bits(struct e
r->entropy_count = r->poolinfo->POOLBITS;
/* should we wake readers? */
- if (r == &input_pool && r->entropy_count >= random_read_wakeup_thresh)
+ if (r == &input_pool &&
+ r->entropy_count >= random_read_wakeup_thresh) {
wake_up_interruptible(&random_read_wait);
+ kill_fasync(&fasync, SIGIO, POLL_IN);
+ }
spin_unlock_irqrestore(&r->lock, flags);
}
@@ -743,8 +747,10 @@ static size_t account(struct entropy_sto
else
r->entropy_count = reserved;
- if (r->entropy_count < random_write_wakeup_thresh)
+ if (r->entropy_count < random_write_wakeup_thresh) {
wake_up_interruptible(&random_write_wait);
+ kill_fasync(&fasync, SIGIO, POLL_OUT);
+ }
}
DEBUG_ENT("debiting %d entropy credits from %s%s\n",
@@ -1101,17 +1107,31 @@ static long random_ioctl(struct file *f,
}
}
+static int random_fasync(int fd, struct file *filp, int on)
+{
+ return fasync_helper(fd, filp, on, &fasync);
+}
+
+static int random_release(struct inode *inode, struct file *filp)
+{
+ return fasync_helper(-1, filp, 0, &fasync);
+}
+
const struct file_operations random_fops = {
.read = random_read,
.write = random_write,
.poll = random_poll,
.unlocked_ioctl = random_ioctl,
+ .fasync = random_fasync,
+ .release = random_release,
};
const struct file_operations urandom_fops = {
.read = urandom_read,
.write = random_write,
.unlocked_ioctl = random_ioctl,
+ .fasync = random_fasync,
+ .release = random_release,
};
/***************************************************************
_
Patches currently in -mm which might be from [EMAIL PROTECTED] are
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git-x86.patch
uml-arch-um-include-inith-needs-a-definition-of-__used.patch
uml-implement-get_wchan.patch
uml-implement-get_wchan-fix.patch
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uml-get-rid-of-asmlinkage-checkpatch-fixes.patch
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uml-further-bugsc-tidying.patch
uml-further-bugsc-tidying-checkpatch-fixes.patch
uml-smp-needs-to-depend-on-broken-for-now.patch
uml-console-driver-cleanups.patch
uml-clonec-tidying.patch
uml-borrow-consth-techniques.patch
uml-delete-some-unused-headers.patch
uml-allow-lflags-on-command-line.patch
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uml-tidy-pgtableh.patch
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uml-reconst-a-parameter.patch
arch-um-remove-duplicate-includes.patch
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uml-move-um_virt_to_phys.patch
uml-header-untangling.patch
uml-header-untangling-fix.patch
uml-style-cleanup.patch
uml-currenth-cleanup.patch
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uml-add-virt_to_pte.patch
uml-simplify-sigsegv-handling.patch
uml-use-ptrace-directly-in-libc-code.patch
uml-kill-processes-instead-of-panicing-kernel.patch
uml-clean-up-task_size-usage.patch
uml-cover-stubs-with-a-vma.patch
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uml-style-fixes-in-arch-um-os-linux.patch
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uml-customize-tlbh.patch
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uml-install-panic-notifier-earlier.patch
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uml-dont-kill-pid-0.patch
uml-get-rid-of-syscall-counters.patch
uml-dont-allow-processes-to-call-into-stub.patch
uml-move-sig_handler_common_skas.patch
uml-clean-up-sig_handler_common_skas.patch
uml-style-fixes-in-arch-um-kernel.patch
uml-signal-handling-tidying.patch
uml-remove-init_irq_signals.patch
fix-__const_udelay-declaration-and-definition-mismatches.patch
create-arch-kconfig.patch
add-have_oprofile.patch
add-have_kprobes.patch
iget-stop-hostfs-from-using-iget-and-read_inode.patch
iget-stop-hostfs-from-using-iget-and-read_inode-checkpatch-fixes.patch
aout-suppress-aout-library-support-if-config_arch_supports_aout-uml-re-remove-accidentally-restored-code.patch
random-add-async-notification-support-to-dev-random.patch
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