[PATCH AUTOSEL 4.19 1/5] leds: trigger: panic: Don't register panic notifier if creating the trigger failed

[PATCH AUTOSEL 4.19 1/5] leds: trigger: panic: Don't register panic notifier if creating the trigger failed

[Sasha Levin]

From: Heiner Kallweit <hkallweit1@gmail.com>

[ Upstream commit afacb21834bb02785ddb0c3ec197208803b74faa ]

It doesn't make sense to register the panic notifier if creating the
panic trigger failed.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/8a61e229-5388-46c7-919a-4d18cc7362b2@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/leds/trigger/ledtrig-panic.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/leds/trigger/ledtrig-panic.c b/drivers/leds/trigger/ledtrig-panic.c
index d735526b9db4..2fc04418a87e 100644
--- a/drivers/leds/trigger/ledtrig-panic.c
+++ b/drivers/leds/trigger/ledtrig-panic.c
@@ -67,10 +67,13 @@ static long led_panic_blink(int state)
 
 static int __init ledtrig_panic_init(void)
 {
+	led_trigger_register_simple("panic", &trigger);
+	if (!trigger)
+		return -ENOMEM;
+
 	atomic_notifier_chain_register(&panic_notifier_list,
 				       &led_trigger_panic_nb);
 
-	led_trigger_register_simple("panic", &trigger);
 	panic_blink = led_panic_blink;
 	return 0;
 }
-- 
2.43.0

[PATCH AUTOSEL 4.19 2/5] um: Fix naming clash between UML and scheduler

[Sasha Levin]

From: Anton Ivanov <anton.ivanov@cambridgegreys.com>

[ Upstream commit 541d4e4d435c8b9bfd29f70a1da4a2db97794e0a ]

__cant_sleep was already used and exported by the scheduler.
The name had to be changed to a UML specific one.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Reviewed-by: Peter Lafreniere <peter@n8pjl.ca>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/um/include/shared/kern_util.h | 2 +-
 arch/um/kernel/process.c           | 2 +-
 arch/um/os-Linux/helper.c          | 6 +++---
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h
index 35ab97e4bb9b..f2da8347d5f5 100644
--- a/arch/um/include/shared/kern_util.h
+++ b/arch/um/include/shared/kern_util.h
@@ -49,7 +49,7 @@ extern void do_uml_exitcalls(void);
  * Are we disallowed to sleep? Used to choose between GFP_KERNEL and
  * GFP_ATOMIC.
  */
-extern int __cant_sleep(void);
+extern int __uml_cant_sleep(void);
 extern int get_current_pid(void);
 extern int copy_from_user_proc(void *to, void *from, int size);
 extern int cpu(void);
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 691b83b10649..c9d09d04d19d 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -210,7 +210,7 @@ void arch_cpu_idle(void)
 	local_irq_enable();
 }
 
-int __cant_sleep(void) {
+int __uml_cant_sleep(void) {
 	return in_atomic() || irqs_disabled() || in_interrupt();
 	/* Is in_interrupt() really needed? */
 }
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index 3f02d4232812..53d450e4a53a 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -45,7 +45,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
 	unsigned long stack, sp;
 	int pid, fds[2], ret, n;
 
-	stack = alloc_stack(0, __cant_sleep());
+	stack = alloc_stack(0, __uml_cant_sleep());
 	if (stack == 0)
 		return -ENOMEM;
 
@@ -69,7 +69,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
 	data.pre_data = pre_data;
 	data.argv = argv;
 	data.fd = fds[1];
-	data.buf = __cant_sleep() ? uml_kmalloc(PATH_MAX, UM_GFP_ATOMIC) :
+	data.buf = __uml_cant_sleep() ? uml_kmalloc(PATH_MAX, UM_GFP_ATOMIC) :
 					uml_kmalloc(PATH_MAX, UM_GFP_KERNEL);
 	pid = clone(helper_child, (void *) sp, CLONE_VM, &data);
 	if (pid < 0) {
@@ -116,7 +116,7 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
 	unsigned long stack, sp;
 	int pid, status, err;
 
-	stack = alloc_stack(0, __cant_sleep());
+	stack = alloc_stack(0, __uml_cant_sleep());
 	if (stack == 0)
 		return -ENOMEM;
 
-- 
2.43.0

[PATCH AUTOSEL 4.19 3/5] um: Don't use vfprintf() for os_info()

[Sasha Levin]

From: Benjamin Berg <benjamin@sipsolutions.net>

[ Upstream commit 236f9fe39b02c15fa5530b53e9cca48354394389 ]

The threads allocated inside the kernel have only a single page of
stack. Unfortunately, the vfprintf function in standard glibc may use
too much stack-space, overflowing it.

To make os_info safe to be used by helper threads, use the kernel
vscnprintf function into a smallish buffer and write out the information
to stderr.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/um/os-Linux/util.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
index 8cc8b2617a67..0436cc9537e0 100644
--- a/arch/um/os-Linux/util.c
+++ b/arch/um/os-Linux/util.c
@@ -166,23 +166,38 @@ __uml_setup("quiet", quiet_cmd_param,
 "quiet\n"
 "    Turns off information messages during boot.\n\n");
 
+/*
+ * The os_info/os_warn functions will be called by helper threads. These
+ * have a very limited stack size and using the libc formatting functions
+ * may overflow the stack.
+ * So pull in the kernel vscnprintf and use that instead with a fixed
+ * on-stack buffer.
+ */
+int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
+
 void os_info(const char *fmt, ...)
 {
+	char buf[256];
 	va_list list;
+	int len;
 
 	if (quiet_info)
 		return;
 
 	va_start(list, fmt);
-	vfprintf(stderr, fmt, list);
+	len = vscnprintf(buf, sizeof(buf), fmt, list);
+	fwrite(buf, len, 1, stderr);
 	va_end(list);
 }
 
 void os_warn(const char *fmt, ...)
 {
+	char buf[256];
 	va_list list;
+	int len;
 
 	va_start(list, fmt);
-	vfprintf(stderr, fmt, list);
+	len = vscnprintf(buf, sizeof(buf), fmt, list);
+	fwrite(buf, len, 1, stderr);
 	va_end(list);
 }
-- 
2.43.0

[PATCH AUTOSEL 4.19 4/5] um: net: Fix return type of uml_net_start_xmit()

[Sasha Levin]

From: Nathan Chancellor <nathan@kernel.org>

[ Upstream commit 7d748f60a4b82b50bf25fad1bd42d33f049f76aa ]

With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed. A
warning in clang aims to catch these at compile time, which reveals:

  arch/um/drivers/net_kern.c:353:21: warning: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Wincompatible-function-pointer-types-strict]
    353 |         .ndo_start_xmit         = uml_net_start_xmit,
        |                                   ^~~~~~~~~~~~~~~~~~
  1 warning generated.

->ndo_start_xmit() in 'struct net_device_ops' expects a return type of
'netdev_tx_t', not 'int'. Adjust the return type of uml_net_start_xmit()
to match the prototype's to resolve the warning. While UML does not
currently implement support for kCFI, it could in the future, which
means this warning becomes a fatal CFI failure at run time.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310031340.v1vPh207-lkp@intel.com/
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/um/drivers/net_kern.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index 3ef1b48e064a..0216e3254c90 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -206,7 +206,7 @@ static int uml_net_close(struct net_device *dev)
 	return 0;
 }
 
-static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct uml_net_private *lp = netdev_priv(dev);
 	unsigned long flags;
-- 
2.43.0

[PATCH AUTOSEL 4.19 5/5] mfd: ti_am335x_tscadc: Fix TI SoC dependencies

[Sasha Levin]

From: Peter Robinson <pbrobinson@gmail.com>

[ Upstream commit 284d16c456e5d4b143f375b8ccc4038ab3f4ee0f ]

The ti_am335x_tscadc is specific to some TI SoCs, update
the dependencies for those SoCs and compile testing.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Link: https://lore.kernel.org/r/20231220155643.445849-1-pbrobinson@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mfd/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index dd938a5d0409..6b7526669875 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1247,6 +1247,7 @@ config MFD_DAVINCI_VOICECODEC
 
 config MFD_TI_AM335X_TSCADC
 	tristate "TI ADC / Touch Screen chip support"
+	depends on ARCH_OMAP2PLUS || ARCH_K3 || COMPILE_TEST
 	select MFD_CORE
 	select REGMAP
 	select REGMAP_MMIO
-- 
2.43.0