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