On Tue, 26 Apr 2011, Arnd Bergmann wrote: > On Friday 22 April 2011, John Calixto wrote: > > Allows appropriately-privileged applications to send CMD (normal) and > > ACMD (application-specific; preceded with CMD55) commands to > > cards/devices on the mmc bus. This is primarily useful for enabling the > > security functionality built in to every SD card. > > > > It can also be used as a generic passthrough (e.g. to enable virtual > > machines to control mmc bus devices directly). However, this use case > > has not been tested rigorously. Generic passthrough testing was only > > conducted for a few non-security opcodes to prove the feasibility of the > > passthrough. > > > > Since any opcode can be sent using this passthrough, it is very possible > > to render the card/device unusable. Applications that use this ioctl > > must have CAP_SYS_RAWIO. > > > > Security commands tested on TI PCIxx12 (SDHCI), Sigma Designs SMP8652 > > SoC, TI OMAP3621 SoC, TI OMAP3630 SoC, Samsung S5PC110 SoC, Qualcomm > > MSM7200A SoC. > > > > Signed-off-by: John Calixto <john.calixto@xxxxxxxxxxxxxx> > > Reviewed-by: Andrei Warkentin <andreiw@xxxxxxxxxxxx> > > The implementation looks good to me now, > > Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx> > > I'll leave the final decision whether this is a good feature to have > to Chris. I still believe that we should have per-command ioctls > for the security feature, but getting there would require someone > to implement it, and I'm not going to do that. > Arnd - Thanks a lot for the review and your help getting the implementation right! Chris - What do you think? How should I proceed here? John -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
