fbdev: offb: Fix OF node name handling
diff mbox series

Message ID 20190107173132.27316-1-robh@kernel.org
State New
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Series
  • fbdev: offb: Fix OF node name handling
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Commit Message

Rob Herring Jan. 7, 2019, 5:31 p.m. UTC
Commit 5c63e407aaab ("fbdev: Convert to using %pOFn instead of
device_node.name") changed how the OF FB driver handles the OF node
name. This missed the case where the node name is passed to
offb_init_palette_hacks(). This results in a NULL ptr dereference
in strncmp and breaks any system except ones using bootx with no display
node.

Fix this by making offb_init_palette_hacks() use the OF node pointer and
use of_node_name_prefix() helper function instead for node name
comparisons. This helps in moving all OF node name accesses to helper
functions in preparation to remove struct device_node.name pointer.

Fixes: 5c63e407aaab ("fbdev: Convert to using %pOFn instead of device_node.name")

Reported-by: Mathieu Malaterre <malat@debian.org>
Cc: stable@vger.kernel.org # v4.19+
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
---
 drivers/video/fbdev/offb.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

Comments

Mathieu Malaterre Jan. 7, 2019, 8:11 p.m. UTC | #1
On Mon, Jan 7, 2019 at 6:31 PM Rob Herring <robh@kernel.org> wrote:
>
> Commit 5c63e407aaab ("fbdev: Convert to using %pOFn instead of
> device_node.name") changed how the OF FB driver handles the OF node
> name. This missed the case where the node name is passed to
> offb_init_palette_hacks(). This results in a NULL ptr dereference
> in strncmp and breaks any system except ones using bootx with no display
> node.
>
> Fix this by making offb_init_palette_hacks() use the OF node pointer and
> use of_node_name_prefix() helper function instead for node name
> comparisons. This helps in moving all OF node name accesses to helper
> functions in preparation to remove struct device_node.name pointer.
>
> Fixes: 5c63e407aaab ("fbdev: Convert to using %pOFn instead of device_node.name")

Looks good to me:

...
[    0.000000] Linux version 5.0.0-rc1+ (malat@debian.org) (gcc
version 6.3.0 20170516 (Debian 6.3.0-18)) #21 Mon Jan 7 21:03:53 CET
2019
...

So here is my :

Tested-by: Mathieu Malaterre <malat@debian.org>

Thanks

> Reported-by: Mathieu Malaterre <malat@debian.org>
> Cc: stable@vger.kernel.org # v4.19+
> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: linux-fbdev@vger.kernel.org
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
>  drivers/video/fbdev/offb.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/video/fbdev/offb.c b/drivers/video/fbdev/offb.c
> index 31f769d67195..057d3cdef92e 100644
> --- a/drivers/video/fbdev/offb.c
> +++ b/drivers/video/fbdev/offb.c
> @@ -318,28 +318,28 @@ static void __iomem *offb_map_reg(struct device_node *np, int index,
>  }
>
>  static void offb_init_palette_hacks(struct fb_info *info, struct device_node *dp,
> -                                   const char *name, unsigned long address)
> +                                   unsigned long address)
>  {
>         struct offb_par *par = (struct offb_par *) info->par;
>
> -       if (dp && !strncmp(name, "ATY,Rage128", 11)) {
> +       if (of_node_name_prefix(dp, "ATY,Rage128")) {
>                 par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
>                 if (par->cmap_adr)
>                         par->cmap_type = cmap_r128;
> -       } else if (dp && (!strncmp(name, "ATY,RageM3pA", 12)
> -                         || !strncmp(name, "ATY,RageM3p12A", 14))) {
> +       } else if (of_node_name_prefix(dp, "ATY,RageM3pA") ||
> +                  of_node_name_prefix(dp, "ATY,RageM3p12A")) {
>                 par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
>                 if (par->cmap_adr)
>                         par->cmap_type = cmap_M3A;
> -       } else if (dp && !strncmp(name, "ATY,RageM3pB", 12)) {
> +       } else if (of_node_name_prefix(dp, "ATY,RageM3pB")) {
>                 par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
>                 if (par->cmap_adr)
>                         par->cmap_type = cmap_M3B;
> -       } else if (dp && !strncmp(name, "ATY,Rage6", 9)) {
> +       } else if (of_node_name_prefix(dp, "ATY,Rage6")) {
>                 par->cmap_adr = offb_map_reg(dp, 1, 0, 0x1fff);
>                 if (par->cmap_adr)
>                         par->cmap_type = cmap_radeon;
> -       } else if (!strncmp(name, "ATY,", 4)) {
> +       } else if (of_node_name_prefix(dp, "ATY,")) {
>                 unsigned long base = address & 0xff000000UL;
>                 par->cmap_adr =
>                         ioremap(base + 0x7ff000, 0x1000) + 0xcc0;
> @@ -350,7 +350,7 @@ static void offb_init_palette_hacks(struct fb_info *info, struct device_node *dp
>                 par->cmap_adr = offb_map_reg(dp, 0, 0x6000, 0x1000);
>                 if (par->cmap_adr)
>                         par->cmap_type = cmap_gxt2000;
> -       } else if (dp && !strncmp(name, "vga,Display-", 12)) {
> +       } else if (of_node_name_prefix(dp, "vga,Display-")) {
>                 /* Look for AVIVO initialized by SLOF */
>                 struct device_node *pciparent = of_get_parent(dp);
>                 const u32 *vid, *did;
> @@ -438,7 +438,7 @@ static void __init offb_init_fb(const char *name,
>
>         par->cmap_type = cmap_unknown;
>         if (depth == 8)
> -               offb_init_palette_hacks(info, dp, name, address);
> +               offb_init_palette_hacks(info, dp, address);
>         else
>                 fix->visual = FB_VISUAL_TRUECOLOR;
>
> --
> 2.19.1
>
Mathieu Malaterre Jan. 7, 2019, 8:36 p.m. UTC | #2
Hi Rob,

On Mon, Jan 7, 2019 at 9:11 PM Mathieu Malaterre <malat@debian.org> wrote:
>
> On Mon, Jan 7, 2019 at 6:31 PM Rob Herring <robh@kernel.org> wrote:
> >
> > Commit 5c63e407aaab ("fbdev: Convert to using %pOFn instead of
> > device_node.name") changed how the OF FB driver handles the OF node
> > name. This missed the case where the node name is passed to
> > offb_init_palette_hacks(). This results in a NULL ptr dereference
> > in strncmp and breaks any system except ones using bootx with no display
> > node.
> >
> > Fix this by making offb_init_palette_hacks() use the OF node pointer and
> > use of_node_name_prefix() helper function instead for node name
> > comparisons. This helps in moving all OF node name accesses to helper
> > functions in preparation to remove struct device_node.name pointer.
> >
> > Fixes: 5c63e407aaab ("fbdev: Convert to using %pOFn instead of device_node.name")
>
> Looks good to me:
>
> ...
> [    0.000000] Linux version 5.0.0-rc1+ (malat@debian.org) (gcc
> version 6.3.0 20170516 (Debian 6.3.0-18)) #21 Mon Jan 7 21:03:53 CET
> 2019
> ...
>
> So here is my :
>
> Tested-by: Mathieu Malaterre <malat@debian.org>

Just for curiosity, why would you keep:

     if (strcmp(dp->name, "valkyrie") == 0)



> > Reported-by: Mathieu Malaterre <malat@debian.org>
> > Cc: stable@vger.kernel.org # v4.19+
> > Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> > Cc: dri-devel@lists.freedesktop.org
> > Cc: linux-fbdev@vger.kernel.org
> > Signed-off-by: Rob Herring <robh@kernel.org>
> > ---
> >  drivers/video/fbdev/offb.c | 18 +++++++++---------
> >  1 file changed, 9 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/video/fbdev/offb.c b/drivers/video/fbdev/offb.c
> > index 31f769d67195..057d3cdef92e 100644
> > --- a/drivers/video/fbdev/offb.c
> > +++ b/drivers/video/fbdev/offb.c
> > @@ -318,28 +318,28 @@ static void __iomem *offb_map_reg(struct device_node *np, int index,
> >  }
> >
> >  static void offb_init_palette_hacks(struct fb_info *info, struct device_node *dp,
> > -                                   const char *name, unsigned long address)
> > +                                   unsigned long address)
> >  {
> >         struct offb_par *par = (struct offb_par *) info->par;
> >
> > -       if (dp && !strncmp(name, "ATY,Rage128", 11)) {
> > +       if (of_node_name_prefix(dp, "ATY,Rage128")) {
> >                 par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
> >                 if (par->cmap_adr)
> >                         par->cmap_type = cmap_r128;
> > -       } else if (dp && (!strncmp(name, "ATY,RageM3pA", 12)
> > -                         || !strncmp(name, "ATY,RageM3p12A", 14))) {
> > +       } else if (of_node_name_prefix(dp, "ATY,RageM3pA") ||
> > +                  of_node_name_prefix(dp, "ATY,RageM3p12A")) {
> >                 par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
> >                 if (par->cmap_adr)
> >                         par->cmap_type = cmap_M3A;
> > -       } else if (dp && !strncmp(name, "ATY,RageM3pB", 12)) {
> > +       } else if (of_node_name_prefix(dp, "ATY,RageM3pB")) {
> >                 par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
> >                 if (par->cmap_adr)
> >                         par->cmap_type = cmap_M3B;
> > -       } else if (dp && !strncmp(name, "ATY,Rage6", 9)) {
> > +       } else if (of_node_name_prefix(dp, "ATY,Rage6")) {
> >                 par->cmap_adr = offb_map_reg(dp, 1, 0, 0x1fff);
> >                 if (par->cmap_adr)
> >                         par->cmap_type = cmap_radeon;
> > -       } else if (!strncmp(name, "ATY,", 4)) {
> > +       } else if (of_node_name_prefix(dp, "ATY,")) {
> >                 unsigned long base = address & 0xff000000UL;
> >                 par->cmap_adr =
> >                         ioremap(base + 0x7ff000, 0x1000) + 0xcc0;
> > @@ -350,7 +350,7 @@ static void offb_init_palette_hacks(struct fb_info *info, struct device_node *dp
> >                 par->cmap_adr = offb_map_reg(dp, 0, 0x6000, 0x1000);
> >                 if (par->cmap_adr)
> >                         par->cmap_type = cmap_gxt2000;
> > -       } else if (dp && !strncmp(name, "vga,Display-", 12)) {
> > +       } else if (of_node_name_prefix(dp, "vga,Display-")) {
> >                 /* Look for AVIVO initialized by SLOF */
> >                 struct device_node *pciparent = of_get_parent(dp);
> >                 const u32 *vid, *did;
> > @@ -438,7 +438,7 @@ static void __init offb_init_fb(const char *name,
> >
> >         par->cmap_type = cmap_unknown;
> >         if (depth == 8)
> > -               offb_init_palette_hacks(info, dp, name, address);
> > +               offb_init_palette_hacks(info, dp, address);
> >         else
> >                 fix->visual = FB_VISUAL_TRUECOLOR;
> >
> > --
> > 2.19.1
> >
Rob Herring Jan. 7, 2019, 11:51 p.m. UTC | #3
On Mon, Jan 7, 2019 at 2:36 PM Mathieu Malaterre <malat@debian.org> wrote:
>
> Hi Rob,
>
> On Mon, Jan 7, 2019 at 9:11 PM Mathieu Malaterre <malat@debian.org> wrote:
> >
> > On Mon, Jan 7, 2019 at 6:31 PM Rob Herring <robh@kernel.org> wrote:
> > >
> > > Commit 5c63e407aaab ("fbdev: Convert to using %pOFn instead of
> > > device_node.name") changed how the OF FB driver handles the OF node
> > > name. This missed the case where the node name is passed to
> > > offb_init_palette_hacks(). This results in a NULL ptr dereference
> > > in strncmp and breaks any system except ones using bootx with no display
> > > node.
> > >
> > > Fix this by making offb_init_palette_hacks() use the OF node pointer and
> > > use of_node_name_prefix() helper function instead for node name
> > > comparisons. This helps in moving all OF node name accesses to helper
> > > functions in preparation to remove struct device_node.name pointer.
> > >
> > > Fixes: 5c63e407aaab ("fbdev: Convert to using %pOFn instead of device_node.name")
> >
> > Looks good to me:
> >
> > ...
> > [    0.000000] Linux version 5.0.0-rc1+ (malat@debian.org) (gcc
> > version 6.3.0 20170516 (Debian 6.3.0-18)) #21 Mon Jan 7 21:03:53 CET
> > 2019
> > ...
> >
> > So here is my :
> >
> > Tested-by: Mathieu Malaterre <malat@debian.org>
>
> Just for curiosity, why would you keep:
>
>      if (strcmp(dp->name, "valkyrie") == 0)

Mainly just because I already have another patch to do that which I
haven't sent out.

Rob
Bartlomiej Zolnierkiewicz Jan. 11, 2019, 12:53 p.m. UTC | #4
On 01/07/2019 09:11 PM, Mathieu Malaterre wrote:
> On Mon, Jan 7, 2019 at 6:31 PM Rob Herring <robh@kernel.org> wrote:
>>
>> Commit 5c63e407aaab ("fbdev: Convert to using %pOFn instead of
>> device_node.name") changed how the OF FB driver handles the OF node
>> name. This missed the case where the node name is passed to
>> offb_init_palette_hacks(). This results in a NULL ptr dereference
>> in strncmp and breaks any system except ones using bootx with no display
>> node.
>>
>> Fix this by making offb_init_palette_hacks() use the OF node pointer and
>> use of_node_name_prefix() helper function instead for node name
>> comparisons. This helps in moving all OF node name accesses to helper
>> functions in preparation to remove struct device_node.name pointer.
>>
>> Fixes: 5c63e407aaab ("fbdev: Convert to using %pOFn instead of device_node.name")
> 
> Looks good to me:
> 
> ...
> [    0.000000] Linux version 5.0.0-rc1+ (malat@debian.org) (gcc
> version 6.3.0 20170516 (Debian 6.3.0-18)) #21 Mon Jan 7 21:03:53 CET
> 2019
> ...
> 
> So here is my :
> 
> Tested-by: Mathieu Malaterre <malat@debian.org>

Patch queued for 5.0, thanks.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

Patch
diff mbox series

diff --git a/drivers/video/fbdev/offb.c b/drivers/video/fbdev/offb.c
index 31f769d67195..057d3cdef92e 100644
--- a/drivers/video/fbdev/offb.c
+++ b/drivers/video/fbdev/offb.c
@@ -318,28 +318,28 @@  static void __iomem *offb_map_reg(struct device_node *np, int index,
 }
 
 static void offb_init_palette_hacks(struct fb_info *info, struct device_node *dp,
-				    const char *name, unsigned long address)
+				    unsigned long address)
 {
 	struct offb_par *par = (struct offb_par *) info->par;
 
-	if (dp && !strncmp(name, "ATY,Rage128", 11)) {
+	if (of_node_name_prefix(dp, "ATY,Rage128")) {
 		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
 		if (par->cmap_adr)
 			par->cmap_type = cmap_r128;
-	} else if (dp && (!strncmp(name, "ATY,RageM3pA", 12)
-			  || !strncmp(name, "ATY,RageM3p12A", 14))) {
+	} else if (of_node_name_prefix(dp, "ATY,RageM3pA") ||
+		   of_node_name_prefix(dp, "ATY,RageM3p12A")) {
 		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
 		if (par->cmap_adr)
 			par->cmap_type = cmap_M3A;
-	} else if (dp && !strncmp(name, "ATY,RageM3pB", 12)) {
+	} else if (of_node_name_prefix(dp, "ATY,RageM3pB")) {
 		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
 		if (par->cmap_adr)
 			par->cmap_type = cmap_M3B;
-	} else if (dp && !strncmp(name, "ATY,Rage6", 9)) {
+	} else if (of_node_name_prefix(dp, "ATY,Rage6")) {
 		par->cmap_adr = offb_map_reg(dp, 1, 0, 0x1fff);
 		if (par->cmap_adr)
 			par->cmap_type = cmap_radeon;
-	} else if (!strncmp(name, "ATY,", 4)) {
+	} else if (of_node_name_prefix(dp, "ATY,")) {
 		unsigned long base = address & 0xff000000UL;
 		par->cmap_adr =
 			ioremap(base + 0x7ff000, 0x1000) + 0xcc0;
@@ -350,7 +350,7 @@  static void offb_init_palette_hacks(struct fb_info *info, struct device_node *dp
 		par->cmap_adr = offb_map_reg(dp, 0, 0x6000, 0x1000);
 		if (par->cmap_adr)
 			par->cmap_type = cmap_gxt2000;
-	} else if (dp && !strncmp(name, "vga,Display-", 12)) {
+	} else if (of_node_name_prefix(dp, "vga,Display-")) {
 		/* Look for AVIVO initialized by SLOF */
 		struct device_node *pciparent = of_get_parent(dp);
 		const u32 *vid, *did;
@@ -438,7 +438,7 @@  static void __init offb_init_fb(const char *name,
 
 	par->cmap_type = cmap_unknown;
 	if (depth == 8)
-		offb_init_palette_hacks(info, dp, name, address);
+		offb_init_palette_hacks(info, dp, address);
 	else
 		fix->visual = FB_VISUAL_TRUECOLOR;