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| author | Pawel Moll <pawel.moll@arm.com> | 2012-11-22 12:30:24 +1030 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2012-12-18 15:20:41 +1030 |
| commit | 40f9938c4c69183c5ceaca74b77aff636cc79623 (patch) | |
| tree | 94393c100ead39d57c4567cb9eca81fe859d72ee /drivers/virtio | |
| parent | eb34f12b509823571e88b791ae2088280943894f (diff) | |
| download | lwn-40f9938c4c69183c5ceaca74b77aff636cc79623.tar.gz lwn-40f9938c4c69183c5ceaca74b77aff636cc79623.zip | |
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>
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/virtio_mmio.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 5a0e1d32ce13..634f80bcdbd7 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -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); |