On Thu, Apr 05, 2018 at 04:09:16PM -0400, David Rivshin wrote:
From: David Rivshin DRivshin@allworx.com
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
I pointed some trivial autotests at both gdb-7.12 and gdb-8.0. Results look good to me!
Tested-by: Daniel Thompson daniel.thompson@linaro.org
arch/arm/include/asm/kgdb.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/kgdb.h b/arch/arm/include/asm/kgdb.h index 3b73fdcf3627a..8de1100d10674 100644 --- a/arch/arm/include/asm/kgdb.h +++ b/arch/arm/include/asm/kgdb.h @@ -77,7 +77,7 @@ extern int kgdb_fault_expected; #define KGDB_MAX_NO_CPUS 1 #define BUFMAX 400 -#define NUMREGBYTES (DBG_MAX_REG_NUM << 2) +#define NUMREGBYTES (GDB_MAX_REGS << 2) #define NUMCRITREGBYTES (32 << 2) #define _R0 0
base-commit: 0adb32858b0bddf4ada5f364a84ed60b196dbcda
2.14.3