linux-brain/arch/arm/probes/uprobes
Fredrik Strupe cec3b778f7 ARM: 9071/1: uprobes: Don't hook on thumb instructions
commit d2f7eca60b29006285d57c7035539e33300e89e5 upstream.

Since uprobes is not supported for thumb, check that the thumb bit is
not set when matching the uprobes instruction hooks.

The Arm UDF instructions used for uprobes triggering
(UPROBE_SWBP_ARM_INSN and UPROBE_SS_ARM_INSN) coincidentally share the
same encoding as a pair of unallocated 32-bit thumb instructions (not
UDF) when the condition code is 0b1111 (0xf). This in effect makes it
possible to trigger the uprobes functionality from thumb, and at that
using two unallocated instructions which are not permanently undefined.

Signed-off-by: Fredrik Strupe <fredrik@strupe.net>
Cc: stable@vger.kernel.org
Fixes: c7edc9e326 ("ARM: add uprobes support")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-21 12:56:18 +02:00
..
actions-arm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
core.c ARM: 9071/1: uprobes: Don't hook on thumb instructions 2021-04-21 12:56:18 +02:00
core.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00