ARM: 8764/1: kgdb: fix NUMREGBYTES so that gdb_regs[] is the correct size
authorDavid Rivshin <DRivshin@allworx.com>
Wed, 25 Apr 2018 20:15:01 +0000 (21:15 +0100)
committerRussell King <rmk+kernel@armlinux.org.uk>
Sat, 19 May 2018 10:53:46 +0000 (11:53 +0100)
commit76ed0b803a2ab793a1b27d1dfe0de7955282cd34
treec9b84538f7ffcc20207fd8c4ef5cd2a41cb8244d
parenta70c3ee34b093bf2b007aceda5b444906f8964c7
ARM: 8764/1: kgdb: fix NUMREGBYTES so that gdb_regs[] is the correct size

NUMREGBYTES (which is used as the size for gdb_regs[]) is incorrectly
based on DBG_MAX_REG_NUM instead of GDB_MAX_REGS. DBG_MAX_REG_NUM
is the number of total registers, while GDB_MAX_REGS is the number
of 'unsigned longs' it takes to serialize those registers. Since
FP registers require 3 'unsigned longs' each, DBG_MAX_REG_NUM is
smaller than GDB_MAX_REGS.

This causes GDB 8.0 give the following error on connect:
"Truncated register 19 in remote 'g' packet"

This also causes the register serialization/deserialization logic
to overflow gdb_regs[], overwriting whatever follows.

Fixes: 834b2964b7ab ("kgdb,arm: fix register dump")
Cc: <stable@vger.kernel.org> # 2.6.37+
Signed-off-by: David Rivshin <drivshin@allworx.com>
Acked-by: Rabin Vincent <rabin@rab.in>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
arch/arm/include/asm/kgdb.h