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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: EAC5F21163 X-Spam-Score: -4.51 X-Rspamd-Action: no action X-Spamd-Result: default: False [-4.51 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; RBL_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:104:10:150:64:97:from]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCVD_TLS_ALL(0.00)[]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:25478, ipnet:::/0, country:RU]; TO_DN_SOME(0.00)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; MID_RHS_MATCH_FROM(0.00)[]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; RCVD_COUNT_TWO(0.00)[2]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_SEVEN(0.00)[7]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:dkim,suse.de:mid,suse.de:email,imap1.dmz-prg2.suse.org:rdns,imap1.dmz-prg2.suse.org:helo]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; DKIM_TRACE(0.00)[suse.de:+] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Spam-Flag: NO X-Spam-Level: Hi, thanks for the updated patch. Am 10.04.25 um 19:43 schrieb Nathan Chancellor: > Clang warns (or errors with CONFIG_WERROR=y): > > drivers/gpu/drm/sysfb/efidrm.c:353:11: error: variable 'screen_base' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] > 353 | else if (mem_flags & EFI_MEMORY_WB) > | ^~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/gpu/drm/sysfb/efidrm.c:356:7: note: uninitialized use occurs here > 356 | if (!screen_base) > | ^~~~~~~~~~~ > drivers/gpu/drm/sysfb/efidrm.c:353:7: note: remove the 'if' if its condition is always true > 353 | else if (mem_flags & EFI_MEMORY_WB) > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 354 | screen_base = devm_memremap(&pdev->dev, mem->start, resource_size(mem), > drivers/gpu/drm/sysfb/efidrm.c:261:27: note: initialize the variable 'screen_base' to silence this warning > 261 | void __iomem *screen_base; > | ^ > | = NULL > > efidrm_get_mem_flags() can only return a mask that has at least one of > the tested values set so the else case is impossible but clang's static > analysis runs before inlining so it cannot know that. > > Initialize screen_base to NULL and add a defensive error message in case > mem_flags were ever returned without one of the four valid values. > > Fixes: 32ae90c66fb6 ("drm/sysfb: Add efidrm for EFI displays") > Reviewed-by: Thomas Zimmermann > Signed-off-by: Nathan Chancellor Reviewed-by: Thomas Zimmermann Best regards Thomas > --- > Changes in v2: > - Upgrade drm_warn() to drm_err() and adjust message (Thomas). > - Carry forward Thomas's reviewed-by. > - Link to v1: https://lore.kernel.org/r/20250409-efidrm-avoid-uninit-screen_info-warning-v1-1-67babb19d831@kernel.org > --- > drivers/gpu/drm/sysfb/efidrm.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/sysfb/efidrm.c b/drivers/gpu/drm/sysfb/efidrm.c > index af90064a4c04..3cfd5d2cbf48 100644 > --- a/drivers/gpu/drm/sysfb/efidrm.c > +++ b/drivers/gpu/drm/sysfb/efidrm.c > @@ -258,7 +258,7 @@ static struct efidrm_device *efidrm_device_create(struct drm_driver *drv, > struct drm_sysfb_device *sysfb; > struct drm_device *dev; > struct resource *mem = NULL; > - void __iomem *screen_base; > + void __iomem *screen_base = NULL; > struct drm_plane *primary_plane; > struct drm_crtc *crtc; > struct drm_encoder *encoder; > @@ -353,6 +353,8 @@ static struct efidrm_device *efidrm_device_create(struct drm_driver *drv, > else if (mem_flags & EFI_MEMORY_WB) > screen_base = devm_memremap(&pdev->dev, mem->start, resource_size(mem), > MEMREMAP_WB); > + else > + drm_err(dev, "invalid mem_flags: 0x%llx\n", mem_flags); > if (!screen_base) > return ERR_PTR(-ENOMEM); > iosys_map_set_vaddr_iomem(&sysfb->fb_addr, screen_base); > > --- > base-commit: e8bf4a1bdaeadb28d13b9a2bcfd5910fda06eede > change-id: 20250409-efidrm-avoid-uninit-screen_info-warning-d62ef67ce3c5 > > Best regards, -- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)