From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
[ Upstream commit 9d0513d82f1a8fe17b41f113ac5922fa57dbaf5c ]
So one of the constification patches unearthed a type casting fragility
of the underlying code:
276c87054751 ("x86/platform/intel-mid: Make 'bt_sfi_data' const")
converted the struct to be const while it is also used as a temporary
container for important data that is used to fill 'parent' and 'name'
fields in struct platform_device_info.
The compiler doesn't notice this due to an explicit type cast that loses
the const - which fragility will be fixed separately.
This type cast turned a seemingly trivial const propagation patch into a
hard to debug data corruptor and crasher bug.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Bhumika Goyal <bhumirks@xxxxxxxxx>
Cc: Darren Hart <dvhart@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: julia.lawall@xxxxxxx
Cc: platform-driver-x86@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20171228122523.21802-1-andriy.shevchenko@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
arch/x86/platform/intel-mid/device_libs/platform_bt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_bt.c b/arch/x86/platform/intel-mid/device_libs/platform_bt.c
index dc036e511f48..5a0483e7bf66 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_bt.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_bt.c
@@ -60,7 +60,7 @@ static int __init tng_bt_sfi_setup(struct bt_sfi_data *ddata)
return 0;
}
-static const struct bt_sfi_data tng_bt_sfi_data __initdata = {
+static struct bt_sfi_data tng_bt_sfi_data __initdata = {
.setup = tng_bt_sfi_setup,
};
--
2.11.0
