[kernel-hardening][PATCH] arm: hw_breakpoint: Mark variables as __ro_after_init

From: Jinbum Park
Date: Mon Dec 11 2017 - 07:50:56 EST


core_num_brps, core_num_wrps, debug_arch, has_ossr,
max_watchpoint_len are setup once while init stage,
and never changed after that.
so it is good candidate for __ro_after_init.

Signed-off-by: Jinbum Park <jinb.park7@xxxxxxxxx>
---
arch/arm/kernel/hw_breakpoint.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index af2a7f1..629e251 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -44,17 +44,17 @@
static DEFINE_PER_CPU(struct perf_event *, wp_on_reg[ARM_MAX_WRP]);

/* Number of BRP/WRP registers on this CPU. */
-static int core_num_brps;
-static int core_num_wrps;
+static int core_num_brps __ro_after_init;
+static int core_num_wrps __ro_after_init;

/* Debug architecture version. */
-static u8 debug_arch;
+static u8 debug_arch __ro_after_init;

/* Does debug architecture support OS Save and Restore? */
-static bool has_ossr;
+static bool has_ossr __ro_after_init;

/* Maximum supported watchpoint length. */
-static u8 max_watchpoint_len;
+static u8 max_watchpoint_len __ro_after_init;

#define READ_WB_REG_CASE(OP2, M, VAL) \
case ((OP2 << 4) + M): \
--
1.9.1