Commit 78e55b52 authored Jan 27, 2023 by Alexander Egorenkov Committed by Greg Kroah-Hartman Feb 22, 2023

watchdog: diag288_wdt: do not use stack buffers for hardware data



commit fe8973a3ad0905cb9ba2d42db42ed51de14737df upstream.

With CONFIG_VMAP_STACK=y the stack is allocated from the vmalloc space.
Data passed to a hardware or a hypervisor interface that
requires V=R can no longer be allocated on the stack.

Use kmalloc() to get memory for a diag288 command.

Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 4abcd352

drivers/watchdog/diag288_wdt.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -272,12 +272,21 @@ static int __init diag288_init(void)
		char ebc_begin[] = {
		194, 197, 199, 201, 213
		};
		char *ebc_cmd;

		watchdog_set_nowayout(&wdt_dev, nowayout_info);

		if (MACHINE_IS_VM) {
		if (__diag288_vm(WDT_FUNC_INIT, 15,
		ebc_begin, sizeof(ebc_begin)) != 0) {
		ebc_cmd = kmalloc(sizeof(ebc_begin), GFP_KERNEL);
		if (!ebc_cmd) {
		pr_err("The watchdog cannot be initialized\n");
		return -ENOMEM;
		}
		memcpy(ebc_cmd, ebc_begin, sizeof(ebc_begin));
		ret = __diag288_vm(WDT_FUNC_INIT, 15,
		ebc_cmd, sizeof(ebc_begin));
		kfree(ebc_cmd);
		if (ret != 0) {
		pr_err("The watchdog cannot be initialized\n");
		return -EINVAL;
		}