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#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include "rnd.h"
#include "die.h"
#include "ioexact.h"
#include "ioops.h"

static int fdw = -1;

static void randombytes_weak(unsigned char *x, size_t xlen)
{
	int ret;

	if (fdw == -1) {
		for (;;) {
			fdw = open(LOW_ENTROPY_SOURCE, O_RDONLY);
			if (fdw != -1)
				break;
			sleep(1);
		}
	}

	while (xlen > 0) {
		if (xlen < 1048576)
			ret = xlen;
		else
			ret = 1048576;

		ret = read(fdw, x, ret);
		if (ret < 1) {
			sleep(1);
			continue;
		}

		x += ret;
		xlen -= ret;
	}
}

static void randombytes_strong(unsigned char *x, size_t xlen)
{
	int fds, ret;

	fds = open_or_die(HIG_ENTROPY_SOURCE, O_RDONLY);

	ret = read_exact(fds, x, xlen, 0);
	if (ret != (int) xlen)
		panic("Error reading from entropy source!\n");

	close(fds);
}

int secrand(void)
{
	int ret;

	randombytes_weak((void *) &ret, sizeof(ret));

	return ret;
}

void gen_key_bytes(unsigned char *area, size_t len)
{
	randombytes_strong(area, len);
}
ww.iagoabal.eu/eba/) reported the following double-lock bug: Double lock: 1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236; 2. call to function `pl330_release_channel' immediately after; 3. call to function `dma_pl330_rqcb' in line 1753; 4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505. I have fixed it as suggested by Marek Szyprowski. First, I have replaced `pch->lock' with `pl330->lock' in functions `pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids the double-lock by acquiring a different lock than `dma_pl330_rqcb'. NOTE that, as a result, `pl330_free_chan_resources' executes `list_splice_tail_init' on `pch->work_list' under lock `pl330->lock', whereas in the rest of the code `pch->work_list' is protected by `pch->lock'. I don't know if this may cause race conditions. Similarly `pch->cyclic' is written by `pl330_alloc_chan_resources' under `pl330->lock' but read by `pl330_tx_submit' under `pch->lock'. Second, I have removed locking from `pl330_request_channel' and `pl330_release_channel' functions. Function `pl330_request_channel' is only called from `pl330_alloc_chan_resources', so the lock is already held. Function `pl330_release_channel' is called from `pl330_free_chan_resources', which already holds the lock, and from `pl330_del'. Function `pl330_del' is called in an error path of `pl330_probe' and at the end of `pl330_remove', but I assume that there cannot be concurrent accesses to the protected data at those points. Signed-off-by: Iago Abal <mail@iagoabal.eu> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'include/xen/balloon.h')