RE: [PATCH] hid_parse failure
From: Pandruvada, Srinivas <hidden>
Date: 2012-05-10 14:04:58
I have a sensor hub device, which exposes this problem. I will send patch again. I will send the patch again. Thanks, Srinivas -----Original Message----- From: Jiri Kosina [mailto:jkosina@suse.cz] Sent: Thursday, May 10, 2012 3:21 AM To: Pandruvada, Srinivas Cc: linux-input@vger.kernel.org Subject: Re: [PATCH] hid_parse failure On Tue, 1 May 2012, srinivas pandruvada wrote:
When logical maximum is 0xffffffff, the parser fails even if logical minimum is equal to or greater than 0. By HID specification, if both the Logical Minimum and Logical Maximum extents are defined as positive values (0 or greater) then the report field can be assumed to be an unsigned value. Otherwise, all integer values are signed values represented in 2’s complement format.
Signed-off-by: line is missing, could you please fix that?
quoted hunk ↗ jump to hunk
--- drivers/hid/hid-core.c | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-)diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c indexc757f10..b616f4b 100644--- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c@@ -225,8 +225,16 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign return -1; } - if (parser->global.logical_maximum < parser->global.logical_minimum) { - dbg_hid("logical range invalid %d %d\n", parser->global.logical_minimum, parser->global.logical_maximum); + if ((parser->global.logical_minimum < 0 && + parser->global.logical_maximum < + parser->global.logical_minimum) || + (parser->global.logical_minimum >= 0 && + (__u32)parser->global.logical_maximum < + (__u32)parser->global.logical_minimum) + ) { + dbg_hid("logical range invalid 0x%x 0x%x\n", + parser->global.logical_minimum, + parser->global.logical_maximum); return -1; }
The change looks correct per se, but I will have to think a little bit more whether other places of report parsing don't need similar adjustments as well to work properly in such scenarios. How did you find this out? By code/spec inspection, or do you actually have the device that exposes this problem? Thanks, -- Jiri Kosina SUSE Labs