ARM: 8124/1: don't enter kgdb when userspace executes a kgdb break instruction

The kgdb breakpoint hooks (kgdb_brk_fn and kgdb_compiled_brk_fn)
should only be entered when a kgdb break instruction is executed
from the kernel. Otherwise, if kgdb is enabled, a userspace program
can cause the kernel to drop into the debugger by executing either
KGDB_BREAKINST or KGDB_COMPILED_BREAK.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Omar Sandoval 2014-08-01 18:14:06 +01:00 committed by Russell King
parent c5cc87fa8d
commit 6bf755db4d
1 changed files with 4 additions and 0 deletions

View File

@ -160,12 +160,16 @@ static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
static struct undef_hook kgdb_brkpt_hook = {
.instr_mask = 0xffffffff,
.instr_val = KGDB_BREAKINST,
.cpsr_mask = MODE_MASK,
.cpsr_val = SVC_MODE,
.fn = kgdb_brk_fn
};
static struct undef_hook kgdb_compiled_brkpt_hook = {
.instr_mask = 0xffffffff,
.instr_val = KGDB_COMPILED_BREAK,
.cpsr_mask = MODE_MASK,
.cpsr_val = SVC_MODE,
.fn = kgdb_compiled_brk_fn
};