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Subject[PATCH] virtio-mmio: Fix irq parsing in command line parameter
Date
On 64-bit machines resource_size_t is a 64-bit value, while
sscanf() format for this argument was defined as "%u". Fixed
by using an intermediate local value of a known length.

Also added cleaned up the resource creation and adde 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>
---
drivers/virtio/virtio_mmio.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 6b1b7e1..0d08843 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -521,25 +521,35 @@ 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;
+ /* Get "size" part of the command line parameter */
+ size = memparse(device, &str) - 1;

+ /* 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);

+ /*
+ * sscanf() processes 3 chunks if "<id>" is given, 2 if not;
+ * also there must be no extra characters after the last
+ * chunk, so str[consumed] should be '\0'
+ */
if (processed < 2 || processed > 3 || str[consumed])
return -EINVAL;

+ /* Memory resource */
+ resources[0].flags = IORESOURCE_MEM;
resources[0].start = base;
- resources[0].end += base;
- resources[1].end = resources[1].start;
+ resources[0].end = base + size;
+
+ /* Interrupt resource */
+ resources[1].flags = IORESOURCE_IRQ;
+ resources[1].start = resources[1].end = irq;

if (!vm_cmdline_parent_registered) {
err = device_register(&vm_cmdline_parent);
--
1.7.10.4



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