Takashi Iwai <tiwai@xxxxxxx> writes: > On Fri, 05 Nov 2021 09:25:13 +0100, > Kalle Valo wrote: >> >> Takashi Iwai <tiwai@xxxxxxx> writes: >> >> > On Fri, 05 Nov 2021 08:17:25 +0100, >> > Takashi Iwai wrote: >> >> >> >> When a firmware is loaded in the compressed format or via user-mode >> >> helper, it's mapped in read-only, and the rtw89 driver crashes at >> >> rtw89_fw_download() when it tries to modify some data. >> >> >> >> This patch is an attemp to avoid the crash by re-allocating the data >> >> via vmalloc() for the data modification. >> > >> > Alternatively, we may drop the code that modifies the loaded firmware >> > data? At least SET_FW_HDR_PART_SIZE() in rtw89_fw_hdr_parser() looks >> > writing it, and I have no idea why this overwrite is needed. >> >> Strange, isn't the firmware data marked as const just to avoid this kind >> of problem? Does rtw89 have wrong casts somewhere which removes the >> const? > > Yes. SET_FW_HDR_PART_SIZE() does the cast, dropping the const. Oh man, all of GET and SET macros in fw.h have those casts: #define GET_FW_HDR_MAJOR_VERSION(fwhdr) \ le32_get_bits(*((__le32 *)(fwhdr) + 1), GENMASK(7, 0)) #define GET_FW_HDR_MINOR_VERSION(fwhdr) \ le32_get_bits(*((__le32 *)(fwhdr) + 1), GENMASK(15, 8)) #define GET_FW_HDR_SUBVERSION(fwhdr) \ le32_get_bits(*((__le32 *)(fwhdr) + 1), GENMASK(23, 16)) I don't know how I missed those during my review :( But this is exactly why I prefer having a proper struct for commands and events, instead of u8 buf used with these macros. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
