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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Archit Taneja <archit@ti.com>,
	Florian Tobias Schandinat <FlorianSchandinat@gmx.de>,
	Chandrabhanu Mahapatra <cmahapatra@ti.com>,
	linux-omap@vger.kernel.org, linux-fbdev@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: Re: [patch] OMAPDSS: reading past end of array in dispc_dump_regs()
Date: Mon, 17 Dec 2012 12:39:19 +0000	[thread overview]
Message-ID: <20121217123919.GF5032@mwanda> (raw)
In-Reply-To: <50CF0B5C.9080707@ti.com>

On Mon, Dec 17, 2012 at 02:09:00PM +0200, Tomi Valkeinen wrote:
> Why does the static checker think OMAP_DSS_WB is needed in the array?

drivers/video/omap2/dss/dispc.c +3284

  3274  #define DISPC_REG(plane, name, i) name(plane, i)
  3275  #define DUMPREG(plane, name, i) \
  3276          seq_printf(s, "%s_%d(%s)%*s %08x\n", #name, i, p_names[plane], \
  3277          (int)(46 - strlen(#name) - strlen(p_names[plane])), " ", \
  3278          dispc_read_reg(DISPC_REG(plane, name, i)))
  3279  
  3280          /* Video pipeline coefficient registers */
  3281  
  3282          /* start from OMAP_DSS_VIDEO1 */
  3283          for (i = 1; i < dss_feat_get_num_ovls(); i++) {
  3284                  for (j = 0; j < 8; j++)
  3285                          DUMPREG(i, DISPC_OVL_FIR_COEF_H, j);

The logic here is that we pass i to DISPC_OVL_FIR_COEF_H() which
passes i to DISPC_FIR_COEF_H_OFFSET().  Anything higher than
OMAP_DSS_WB will trigger a BUG() in DISPC_FIR_COEF_H_OFFSET().

So it's not rock hard logic at all.

regards,
dan carpenter


WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Archit Taneja <archit@ti.com>,
	Florian Tobias Schandinat <FlorianSchandinat@gmx.de>,
	Chandrabhanu Mahapatra <cmahapatra@ti.com>,
	linux-omap@vger.kernel.org, linux-fbdev@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: Re: [patch] OMAPDSS: reading past end of array in dispc_dump_regs()
Date: Mon, 17 Dec 2012 15:39:19 +0300	[thread overview]
Message-ID: <20121217123919.GF5032@mwanda> (raw)
In-Reply-To: <50CF0B5C.9080707@ti.com>

On Mon, Dec 17, 2012 at 02:09:00PM +0200, Tomi Valkeinen wrote:
> Why does the static checker think OMAP_DSS_WB is needed in the array?

drivers/video/omap2/dss/dispc.c +3284

  3274  #define DISPC_REG(plane, name, i) name(plane, i)
  3275  #define DUMPREG(plane, name, i) \
  3276          seq_printf(s, "%s_%d(%s)%*s %08x\n", #name, i, p_names[plane], \
  3277          (int)(46 - strlen(#name) - strlen(p_names[plane])), " ", \
  3278          dispc_read_reg(DISPC_REG(plane, name, i)))
  3279  
  3280          /* Video pipeline coefficient registers */
  3281  
  3282          /* start from OMAP_DSS_VIDEO1 */
  3283          for (i = 1; i < dss_feat_get_num_ovls(); i++) {
  3284                  for (j = 0; j < 8; j++)
  3285                          DUMPREG(i, DISPC_OVL_FIR_COEF_H, j);

The logic here is that we pass i to DISPC_OVL_FIR_COEF_H() which
passes i to DISPC_FIR_COEF_H_OFFSET().  Anything higher than
OMAP_DSS_WB will trigger a BUG() in DISPC_FIR_COEF_H_OFFSET().

So it's not rock hard logic at all.

regards,
dan carpenter


  reply	other threads:[~2012-12-17 12:39 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-14 15:01 [patch] OMAPDSS: reading past end of array in dispc_dump_regs() Dan Carpenter
2012-12-14 15:01 ` Dan Carpenter
2012-12-17 12:09 ` Tomi Valkeinen
2012-12-17 12:09   ` Tomi Valkeinen
2012-12-17 12:39   ` Dan Carpenter [this message]
2012-12-17 12:39     ` Dan Carpenter

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