mmc: core: Add mmc CMD+ACMD passthrough ioctl
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/OMAP3630 SoC, Samsung S5PC110 SoC, Qualcomm MSM7200A SoC.
Signed-off-by: John Calixto <john.calixto@modsystems.com>
Reviewed-by: Andrei Warkentin <andreiw@motorola.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index a0a5d82..2a34d82 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -304,6 +304,7 @@
0xB0 all RATIO devices in development:
<mailto:vgo@ratio.de>
0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca>
+0xB3 00 linux/mmc/ioctl.h
0xC0 00-0F linux/usb/iowarrior.h
0xCB 00-1F CBM serial IEC bus in development:
<mailto:michael.klein@puffin.lb.shuttle.de>