4.20-stable review patch. If anyone has any objections, please let me know.
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From: Rob Herring robh@kernel.org
commit 00257e0cc550c4a8df5f99c0a4fc74fec0656144 upstream.
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 Tested-by: Mathieu Malaterre malat@debian.org Cc: stable@vger.kernel.org # v4.19+ Cc: Elimar Riesebieter riesebie@lxtec.de Signed-off-by: Rob Herring robh@kernel.org Signed-off-by: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/video/fbdev/offb.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)
--- a/drivers/video/fbdev/offb.c +++ b/drivers/video/fbdev/offb.c @@ -318,28 +318,28 @@ static void __iomem *offb_map_reg(struct }
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(stru 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 ch
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;