On Thu, Apr 05, 2018 at 04:09:16PM -0400, David Rivshin wrote:
From: David Rivshin <DRivshin@xxxxxxxxxxx>
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@xxxxxxxxxxxxxxx> # 2.6.37+
Signed-off-by: David Rivshin <drivshin@xxxxxxxxxxx>
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@xxxxxxxxxx>
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
@@ -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