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virtio-mmio: Fix irq parsing in command line parameter 

When the resource_size_t is 64-bit long, the sscanf() on
the virtio device command line paramter string may return
wrong value because its format was defined as "%u". Fixed
by using an intermediate local value of a known length.

Also added cleaned up the resource creation and added extra
comments to make the parameters parsing easier to follow.

Reported-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Pawel Moll 2012-11-22 12:30:24 +10:30 committed by Rusty Russell
parent eb34f12b50
commit 40f9938c4c
1 changed files with 17 additions and 9 deletions
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26
drivers/virtio/virtio_mmio.c
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@ -521,25 +521,33 @@ static int vm_cmdline_set(const char *device,
int err;
struct resource resources[2] = {};
char *str;
long long int base;
long long int base, size;
unsigned int irq;
int processed, consumed = 0;
struct platform_device *pdev;
resources[0].flags = IORESOURCE_MEM;
resources[1].flags = IORESOURCE_IRQ;
resources[0].end = memparse(device, &str) - 1;
/* Consume "size" part of the command line parameter */
size = memparse(device, &str);
/* Get "@<base>:<irq>[:<id>]" chunks */
processed = sscanf(str, "@%lli:%u%n:%d%n",
&base, &resources[1].start, &consumed,
&base, &irq, &consumed,
&vm_cmdline_id, &consumed);
if (processed < 2 || processed > 3 || str[consumed])
/*
* sscanf() must processes at least 2 chunks; also there
* must be no extra characters after the last chunk, so
* str[consumed] must be '\0'
*/
if (processed < 2 || str[consumed])
return -EINVAL;
resources[0].flags = IORESOURCE_MEM;
resources[0].start = base;
resources[0].end += base;
resources[1].end = resources[1].start;
resources[0].end = base + size - 1;
resources[1].flags = IORESOURCE_IRQ;
resources[1].start = resources[1].end = irq;
if (!vm_cmdline_parent_registered) {
err = device_register(&vm_cmdline_parent);