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#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <stdbool.h>

#include "ioexact.h"

extern volatile sig_atomic_t sigint;

ssize_t read_exact(int fd, void *buf, size_t len, bool mayexit)
{
	ssize_t num = 0, written;

	while (len > 0 && !sigint) {
		if ((written = read(fd, buf, len)) < 0) {
			if (errno == EAGAIN && num > 0)
				continue;
			if (mayexit)
				return -1;
			else
				continue;
		}
		if (!written)
			return 0;

		len -= written;
		buf += written;
		num += written;
	}

	return num;
}

ssize_t write_exact(int fd, void *buf, size_t len, bool mayexit)
{
	ssize_t num = 0, written;

	while (len > 0 && !sigint) {
		if ((written = write(fd, buf, len)) < 0) {
			if (errno == EAGAIN && num > 0)
				continue;
			if (mayexit)
				return -1;
			else
				continue;
		}
		if (!written)
			return 0;

		len -= written;
		buf += written;
		num += written;
	}

	return num;
}
'>dmaengine: pl330: fix double lock
The static bug finder EBA (http://www.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 'sound/pci/ctxfi/ctresource.c')