diff mbox series

[v7,1/2] kexec: Introduce kexec_with_frozen_processes

Message ID 20221127-snd-freeze-v7-1-127c582f1ca4@chromium.org
State New
Headers
Series ASoC: SOF: Fix deadlock when shutdown a frozen userspace |

Commit Message

Ricardo Ribalda Nov. 30, 2022, 4:29 p.m. UTC 
  Drivers running .shutdown() might want to wait for userspace to complete
before exiting.

If userspace is frozen and we are running kexec they will stall the
computer.

Add a way for them to figure out if they should just skip waiting for
userspace.

Cc: stable@vger.kernel.org
Fixes: 83bfc7e793b5 ("ASoC: SOF: core: unregister clients and machine drivers in .shutdown")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 include/linux/kexec.h | 3 +++
 kernel/kexec_core.c   | 5 +++++
 2 files changed, 8 insertions(+)

Comments

kernel test robot Dec. 1, 2022, 5:24 a.m. UTC | #1 
Hi Ricardo,

I love your patch! Yet something to improve:

[auto build test ERROR on 4312098baf37ee17a8350725e6e0d0e8590252d4]

url:    https://github.com/intel-lab-lkp/linux/commits/Ricardo-Ribalda/ASoC-SOF-Fix-deadlock-when-shutdown-a-frozen-userspace/20221201-003214
base:   4312098baf37ee17a8350725e6e0d0e8590252d4
patch link:    https://lore.kernel.org/r/20221127-snd-freeze-v7-1-127c582f1ca4%40chromium.org
patch subject: [PATCH v7 1/2] kexec: Introduce kexec_with_frozen_processes
config: ia64-randconfig-r022-20221128
compiler: ia64-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/ddb7195380bb431ff9f4505d5fcfbef756b80a3a
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Ricardo-Ribalda/ASoC-SOF-Fix-deadlock-when-shutdown-a-frozen-userspace/20221201-003214
        git checkout ddb7195380bb431ff9f4505d5fcfbef756b80a3a
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=ia64 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   kernel/kexec_core.c: In function 'kexec_with_frozen_processes':
>> kernel/kexec_core.c:59:37: error: 'pm_freezing' undeclared (first use in this function); did you mean 'freezing'?
      59 |         return kexec_in_progress && pm_freezing;
         |                                     ^~~~~~~~~~~
         |                                     freezing
   kernel/kexec_core.c:59:37: note: each undeclared identifier is reported only once for each function it appears in
   kernel/kexec_core.c:60:1: error: control reaches end of non-void function [-Werror=return-type]
      60 | }
         | ^
   cc1: some warnings being treated as errors


vim +59 kernel/kexec_core.c

    56	
    57	bool kexec_with_frozen_processes(void)
    58	{
  > 59		return kexec_in_progress && pm_freezing;
    60	}
    61	EXPORT_SYMBOL(kexec_with_frozen_processes);
    62
kernel test robot Dec. 1, 2022, 8:53 p.m. UTC | #2 
Hi Ricardo,

I love your patch! Yet something to improve:

[auto build test ERROR on 4312098baf37ee17a8350725e6e0d0e8590252d4]

url:    https://github.com/intel-lab-lkp/linux/commits/Ricardo-Ribalda/ASoC-SOF-Fix-deadlock-when-shutdown-a-frozen-userspace/20221201-003214
base:   4312098baf37ee17a8350725e6e0d0e8590252d4
patch link:    https://lore.kernel.org/r/20221127-snd-freeze-v7-1-127c582f1ca4%40chromium.org
patch subject: [PATCH v7 1/2] kexec: Introduce kexec_with_frozen_processes
config: s390-randconfig-r024-20221128
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 6e4cea55f0d1104408b26ac574566a0e4de48036)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/ddb7195380bb431ff9f4505d5fcfbef756b80a3a
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Ricardo-Ribalda/ASoC-SOF-Fix-deadlock-when-shutdown-a-frozen-userspace/20221201-003214
        git checkout ddb7195380bb431ff9f4505d5fcfbef756b80a3a
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

   In file included from kernel/kexec_core.c:14:
   In file included from include/linux/kexec.h:19:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __raw_readb(PCI_IOBASE + addr);
                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
                                                           ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu'
   #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
                                                             ^
   include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
   #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
                                                        ^
   In file included from kernel/kexec_core.c:14:
   In file included from include/linux/kexec.h:19:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
                                                           ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu'
   #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
                                                             ^
   include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
   #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
                                                        ^
   In file included from kernel/kexec_core.c:14:
   In file included from include/linux/kexec.h:19:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writeb(value, PCI_IOBASE + addr);
                               ~~~~~~~~~~ ^
   include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
                                                         ~~~~~~~~~~ ^
   include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
                                                         ~~~~~~~~~~ ^
   include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           readsb(PCI_IOBASE + addr, buffer, count);
                  ~~~~~~~~~~ ^
   include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           readsw(PCI_IOBASE + addr, buffer, count);
                  ~~~~~~~~~~ ^
   include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           readsl(PCI_IOBASE + addr, buffer, count);
                  ~~~~~~~~~~ ^
   include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           writesb(PCI_IOBASE + addr, buffer, count);
                   ~~~~~~~~~~ ^
   include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           writesw(PCI_IOBASE + addr, buffer, count);
                   ~~~~~~~~~~ ^
   include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           writesl(PCI_IOBASE + addr, buffer, count);
                   ~~~~~~~~~~ ^
>> kernel/kexec_core.c:59:30: error: use of undeclared identifier 'pm_freezing'; did you mean 'freezing'?
           return kexec_in_progress && pm_freezing;
                                       ^~~~~~~~~~~
                                       freezing
   include/linux/freezer.h:75:20: note: 'freezing' declared here
   static inline bool freezing(struct task_struct *p) { return false; }
                      ^
>> kernel/kexec_core.c:59:30: warning: address of function 'freezing' will always evaluate to 'true' [-Wpointer-bool-conversion]
           return kexec_in_progress && pm_freezing;
                                    ~~ ^~~~~~~~~~~
   kernel/kexec_core.c:59:30: note: prefix with the address-of operator to silence this warning
           return kexec_in_progress && pm_freezing;
                                       ^
                                       &
   13 warnings and 1 error generated.


vim +59 kernel/kexec_core.c

    56	
    57	bool kexec_with_frozen_processes(void)
    58	{
  > 59		return kexec_in_progress && pm_freezing;
    60	}
    61	EXPORT_SYMBOL(kexec_with_frozen_processes);
    62
diff mbox series

Patch

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 41a686996aaa..c22711e0f7b5 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -426,6 +426,8 @@  extern int kexec_load_disabled;
 /* flag to track if kexec reboot is in progress */
 extern bool kexec_in_progress;
 
+bool kexec_with_frozen_processes(void);
+
 int crash_shrink_memory(unsigned long new_size);
 ssize_t crash_get_memory_size(void);
 
@@ -507,6 +509,7 @@  static inline void __crash_kexec(struct pt_regs *regs) { }
 static inline void crash_kexec(struct pt_regs *regs) { }
 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
 static inline int kexec_crash_loaded(void) { return 0; }
+static inline bool kexec_with_frozen_processes(void) { return false; }
 #define kexec_in_progress false
 #endif /* CONFIG_KEXEC_CORE */
 
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index ca2743f9c634..8bc8257ee7ca 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -54,6 +54,11 @@  note_buf_t __percpu *crash_notes;
 /* Flag to indicate we are going to kexec a new kernel */
 bool kexec_in_progress = false;
 
+bool kexec_with_frozen_processes(void)
+{
+	return kexec_in_progress && pm_freezing;
+}
+EXPORT_SYMBOL(kexec_with_frozen_processes);
 
 /* Location of the reserved area for the crash kernel */
 struct resource crashk_res = {