Don't break into kgdb when userspace executes the kernel break instructions
(KGDB_BREAKINST and KGDB_COMPILED_BREAK). The kernel will oops in
kgdb_handle_exception.
Signed-off-by: Omar Sandoval <osan...@osandov.com>
---
The following program will immediately cause a kernel oops:
.globl _start
_start:
udf #65006 @ KGDB_BREAKINST
arch/arm/kernel/kgdb.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c
index 778c2f7..a74b53c 100644
--- a/arch/arm/kernel/kgdb.c
+++ b/arch/arm/kernel/kgdb.c
@@ -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
};
--
2.0.1
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