From: Guo Ren <guoren@linux.alibaba.com>
Current crash_smp_send_stop is the same as the generic one in
kernel/panic. without crash_save_cpu in percpu. This patch is inspired
by 78fd584cdec0 ("arm64: kdump: implement machine_crash_shutdown()")
and adds the same mechanism for riscv.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
---
arch/riscv/include/asm/smp.h | 6 +++
arch/riscv/kernel/machine_kexec.c | 19 ++-----
arch/riscv/kernel/smp.c | 89 ++++++++++++++++++++++++++++++-
3 files changed, 96 insertions(+), 18 deletions(-)
diff --git a/arch/riscv/include/asm/smp.h b/arch/riscv/include/asm/smp.h
index d3443be7eedc..e0ddbfcf7c43 100644
--- a/arch/riscv/include/asm/smp.h
+++ b/arch/riscv/include/asm/smp.h
@@ -50,6 +50,12 @@ void riscv_set_ipi_ops(const struct riscv_ipi_ops *ops);
/* Clear IPI for current CPU */
void riscv_clear_ipi(void);
+/* stop and save status for other CPUs */
+void crash_smp_send_stop(void);
+
+/* Check other CPUs stop or not */
+extern bool smp_crash_stop_failed(void);
+
/* Secondary hart entry */
asmlinkage void smp_callin(void);
diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c
index db41c676e5a2..34c86d337448 100644
--- a/arch/riscv/kernel/machine_kexec.c
+++ b/arch/riscv/kernel/machine_kexec.c
@@ -140,22 +140,6 @@ void machine_shutdown(void)
#endif
}
-/* Override the weak function in kernel/panic.c */
-void crash_smp_send_stop(void)
-{
- static int cpus_stopped;
-
- /*
- * This function can be called twice in panic path, but obviously
- * we execute this only once.
- */
- if (cpus_stopped)
- return;
-
- smp_send_stop();
- cpus_stopped = 1;
-}
-
static void machine_kexec_mask_interrupts(void)
{
unsigned int i;
@@ -230,6 +214,9 @@ machine_kexec(struct kimage *image)
void *control_code_buffer = page_address(image->control_code_page);
riscv_kexec_method kexec_method = NULL;
+ WARN(smp_crash_stop_failed(),
+ "Some CPUs may be stale, kdump will be unreliable.\n");
+
if (image->type != KEXEC_TYPE_CRASH)
kexec_method = control_code_buffer;
else
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 760a64518c58..a75ad9c373cd 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -12,6 +12,7 @@
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/module.h>
+#include <linux/kexec.h>
#include <linux/profile.h>
#include <linux/smp.h>
#include <linux/sched.h>
@@ -27,6 +28,7 @@ enum ipi_message_type {
IPI_RESCHEDULE,
IPI_CALL_FUNC,
IPI_CPU_STOP,
+ IPI_CPU_CRASH_STOP,
IPI_IRQ_WORK,
IPI_TIMER,
IPI_MAX
@@ -71,6 +73,22 @@ static void ipi_stop(void)
wait_for_interrupt();
}
+#ifdef CONFIG_KEXEC_CORE
+static atomic_t waiting_for_crash_ipi = ATOMIC_INIT(0);
+
+static void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs)
+{
+ crash_save_cpu(regs, cpu);
+
+ atomic_dec(&waiting_for_crash_ipi);
+
+ local_irq_disable();
+
+ while(1)
+ wait_for_interrupt();
+}
+#endif
+
static const struct riscv_ipi_ops *ipi_ops __ro_after_init;
void riscv_set_ipi_ops(const struct riscv_ipi_ops *ops)
@@ -124,8 +142,9 @@ void arch_irq_work_raise(void)
void handle_IPI(struct pt_regs *regs)
{
- unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits;
- unsigned long *stats = ipi_data[smp_processor_id()].stats;
+ unsigned int cpu = smp_processor_id();
+ unsigned long *pending_ipis = &ipi_data[cpu].bits;
+ unsigned long *stats = ipi_data[cpu].stats;
riscv_clear_ipi();
@@ -154,6 +173,13 @@ void handle_IPI(struct pt_regs *regs)
ipi_stop();
}
+ if (ops & (1 << IPI_CPU_CRASH_STOP)) {
+#ifdef CONFIG_KEXEC_CORE
+ ipi_cpu_crash_stop(cpu, get_irq_regs());
+#endif
+ unreachable();
+ }
+
if (ops & (1 << IPI_IRQ_WORK)) {
stats[IPI_IRQ_WORK]++;
irq_work_run();
@@ -176,6 +202,7 @@ static const char * const ipi_names[] = {
[IPI_RESCHEDULE] = "Rescheduling interrupts",
[IPI_CALL_FUNC] = "Function call interrupts",
[IPI_CPU_STOP] = "CPU stop interrupts",
+ [IPI_CPU_CRASH_STOP] = "CPU stop (for crash dump) interrupts",
[IPI_IRQ_WORK] = "IRQ work interrupts",
[IPI_TIMER] = "Timer broadcast interrupts",
};
@@ -235,6 +262,64 @@ void smp_send_stop(void)
cpumask_pr_args(cpu_online_mask));
}
+#ifdef CONFIG_KEXEC_CORE
+/*
+ * The number of CPUs online, not counting this CPU (which may not be
+ * fully online and so not counted in num_online_cpus()).
+ */
+static inline unsigned int num_other_online_cpus(void)
+{
+ unsigned int this_cpu_online = cpu_online(smp_processor_id());
+
+ return num_online_cpus() - this_cpu_online;
+}
+
+void crash_smp_send_stop(void)
+{
+ static int cpus_stopped;
+ cpumask_t mask;
+ unsigned long timeout;
+
+ /*
+ * This function can be called twice in panic path, but obviously
+ * we execute this only once.
+ */
+ if (cpus_stopped)
+ return;
+
+ cpus_stopped = 1;
+
+ /*
+ * If this cpu is the only one alive at this point in time, online or
+ * not, there are no stop messages to be sent around, so just back out.
+ */
+ if (num_other_online_cpus() == 0)
+ return;
+
+ cpumask_copy(&mask, cpu_online_mask);
+ cpumask_clear_cpu(smp_processor_id(), &mask);
+
+ atomic_set(&waiting_for_crash_ipi, num_other_online_cpus());
+
+ pr_crit("SMP: stopping secondary CPUs\n");
+ send_ipi_mask(&mask, IPI_CPU_CRASH_STOP);
+
+ /* Wait up to one second for other CPUs to stop */
+ timeout = USEC_PER_SEC;
+ while ((atomic_read(&waiting_for_crash_ipi) > 0) && timeout--)
+ udelay(1);
+
+ if (atomic_read(&waiting_for_crash_ipi) > 0)
+ pr_warn("SMP: failed to stop secondary CPUs %*pbl\n",
+ cpumask_pr_args(&mask));
+}
+
+bool smp_crash_stop_failed(void)
+{
+ return (atomic_read(&waiting_for_crash_ipi) > 0);
+}
+#endif
+
void smp_send_reschedule(int cpu)
{
send_ipi_single(cpu, IPI_RESCHEDULE);
--
2.36.1Hi,
I love your patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v6.0-rc1 next-20220818]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/guoren-kernel-org/riscv-kexec-Support-crash_save-percpu-and-machine_kexec_mask_interrupts/20220816-144442
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 568035b01cfb107af8d2e4bd2fb9aea22cf5b868
config: riscv-buildonly-randconfig-r002-20220818 (https://download.01.org/0day-ci/archive/20220818/202208181655.NrkPo4lG-lkp@intel.com/config)
compiler: riscv64-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/0abdaf7e1f44634e1cee484e3cf01b7e8c851950
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review guoren-kernel-org/riscv-kexec-Support-crash_save-percpu-and-machine_kexec_mask_interrupts/20220816-144442
git checkout 0abdaf7e1f44634e1cee484e3cf01b7e8c851950
# 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=riscv 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 >>):
In file included from arch/riscv/include/asm/bug.h:83,
from include/linux/bug.h:5,
from include/linux/elfcore.h:6,
from include/linux/crash_core.h:6,
from include/linux/kexec.h:18,
from arch/riscv/kernel/machine_kexec.c:7:
arch/riscv/kernel/machine_kexec.c: In function 'machine_kexec':
>> arch/riscv/kernel/machine_kexec.c:217:14: error: implicit declaration of function 'smp_crash_stop_failed' [-Werror=implicit-function-declaration]
217 | WARN(smp_crash_stop_failed(),
| ^~~~~~~~~~~~~~~~~~~~~
include/asm-generic/bug.h:174:32: note: in definition of macro 'WARN'
174 | int __ret_warn_on = !!(condition); \
| ^~~~~~~~~
cc1: some warnings being treated as errors
vim +/smp_crash_stop_failed +217 arch/riscv/kernel/machine_kexec.c
193
194 /*
195 * machine_kexec - Jump to the loaded kimage
196 *
197 * This function is called by kernel_kexec which is called by the
198 * reboot system call when the reboot cmd is LINUX_REBOOT_CMD_KEXEC,
199 * or by crash_kernel which is called by the kernel's arch-specific
200 * trap handler in case of a kernel panic. It's the final stage of
201 * the kexec process where the pre-loaded kimage is ready to be
202 * executed. We assume at this point that all other harts are
203 * suspended and this hart will be the new boot hart.
204 */
205 void __noreturn
206 machine_kexec(struct kimage *image)
207 {
208 struct kimage_arch *internal = &image->arch;
209 unsigned long jump_addr = (unsigned long) image->start;
210 unsigned long first_ind_entry = (unsigned long) &image->head;
211 unsigned long this_cpu_id = __smp_processor_id();
212 unsigned long this_hart_id = cpuid_to_hartid_map(this_cpu_id);
213 unsigned long fdt_addr = internal->fdt_addr;
214 void *control_code_buffer = page_address(image->control_code_page);
215 riscv_kexec_method kexec_method = NULL;
216
> 217 WARN(smp_crash_stop_failed(),
--
0-DAY CI Kernel Test Service
https://01.org/lkp
Hi,
I love your patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v6.0-rc1 next-20220818]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/guoren-kernel-org/riscv-kexec-Support-crash_save-percpu-and-machine_kexec_mask_interrupts/20220816-144442
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 568035b01cfb107af8d2e4bd2fb9aea22cf5b868
config: riscv-randconfig-r035-20220818 (https://download.01.org/0day-ci/archive/20220818/202208181520.fYQOePu6-lkp@intel.com/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project aed5e3bea138ce581d682158eb61c27b3cfdd6ec)
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 riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/0abdaf7e1f44634e1cee484e3cf01b7e8c851950
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review guoren-kernel-org/riscv-kexec-Support-crash_save-percpu-and-machine_kexec_mask_interrupts/20220816-144442
git checkout 0abdaf7e1f44634e1cee484e3cf01b7e8c851950
# 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=riscv SHELL=/bin/bash arch/riscv/kernel/
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 >>):
>> arch/riscv/kernel/machine_kexec.c:217:7: error: call to undeclared function 'smp_crash_stop_failed'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
WARN(smp_crash_stop_failed(),
^
1 error generated.
vim +/smp_crash_stop_failed +217 arch/riscv/kernel/machine_kexec.c
193
194 /*
195 * machine_kexec - Jump to the loaded kimage
196 *
197 * This function is called by kernel_kexec which is called by the
198 * reboot system call when the reboot cmd is LINUX_REBOOT_CMD_KEXEC,
199 * or by crash_kernel which is called by the kernel's arch-specific
200 * trap handler in case of a kernel panic. It's the final stage of
201 * the kexec process where the pre-loaded kimage is ready to be
202 * executed. We assume at this point that all other harts are
203 * suspended and this hart will be the new boot hart.
204 */
205 void __noreturn
206 machine_kexec(struct kimage *image)
207 {
208 struct kimage_arch *internal = &image->arch;
209 unsigned long jump_addr = (unsigned long) image->start;
210 unsigned long first_ind_entry = (unsigned long) &image->head;
211 unsigned long this_cpu_id = __smp_processor_id();
212 unsigned long this_hart_id = cpuid_to_hartid_map(this_cpu_id);
213 unsigned long fdt_addr = internal->fdt_addr;
214 void *control_code_buffer = page_address(image->control_code_page);
215 riscv_kexec_method kexec_method = NULL;
216
> 217 WARN(smp_crash_stop_failed(),
--
0-DAY CI Kernel Test Service
https://01.org/lkp
Thx, It's a bug from !SMP. I would fixup it in the next version.
On Thu, Aug 18, 2022 at 3:58 PM kernel test robot <lkp@intel.com> wrote:
>
> Hi,
>
> I love your patch! Yet something to improve:
>
> [auto build test ERROR on linus/master]
> [also build test ERROR on v6.0-rc1 next-20220818]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/guoren-kernel-org/riscv-kexec-Support-crash_save-percpu-and-machine_kexec_mask_interrupts/20220816-144442
> base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 568035b01cfb107af8d2e4bd2fb9aea22cf5b868
> config: riscv-randconfig-r035-20220818 (https://download.01.org/0day-ci/archive/20220818/202208181520.fYQOePu6-lkp@intel.com/config)
> compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project aed5e3bea138ce581d682158eb61c27b3cfdd6ec)
> 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 riscv cross compiling tool for clang build
> # apt-get install binutils-riscv64-linux-gnu
> # https://github.com/intel-lab-lkp/linux/commit/0abdaf7e1f44634e1cee484e3cf01b7e8c851950
> git remote add linux-review https://github.com/intel-lab-lkp/linux
> git fetch --no-tags linux-review guoren-kernel-org/riscv-kexec-Support-crash_save-percpu-and-machine_kexec_mask_interrupts/20220816-144442
> git checkout 0abdaf7e1f44634e1cee484e3cf01b7e8c851950
> # 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=riscv SHELL=/bin/bash arch/riscv/kernel/
>
> 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 >>):
>
> >> arch/riscv/kernel/machine_kexec.c:217:7: error: call to undeclared function 'smp_crash_stop_failed'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
> WARN(smp_crash_stop_failed(),
> ^
> 1 error generated.
>
>
> vim +/smp_crash_stop_failed +217 arch/riscv/kernel/machine_kexec.c
>
> 193
> 194 /*
> 195 * machine_kexec - Jump to the loaded kimage
> 196 *
> 197 * This function is called by kernel_kexec which is called by the
> 198 * reboot system call when the reboot cmd is LINUX_REBOOT_CMD_KEXEC,
> 199 * or by crash_kernel which is called by the kernel's arch-specific
> 200 * trap handler in case of a kernel panic. It's the final stage of
> 201 * the kexec process where the pre-loaded kimage is ready to be
> 202 * executed. We assume at this point that all other harts are
> 203 * suspended and this hart will be the new boot hart.
> 204 */
> 205 void __noreturn
> 206 machine_kexec(struct kimage *image)
> 207 {
> 208 struct kimage_arch *internal = &image->arch;
> 209 unsigned long jump_addr = (unsigned long) image->start;
> 210 unsigned long first_ind_entry = (unsigned long) &image->head;
> 211 unsigned long this_cpu_id = __smp_processor_id();
> 212 unsigned long this_hart_id = cpuid_to_hartid_map(this_cpu_id);
> 213 unsigned long fdt_addr = internal->fdt_addr;
> 214 void *control_code_buffer = page_address(image->control_code_page);
> 215 riscv_kexec_method kexec_method = NULL;
> 216
> > 217 WARN(smp_crash_stop_failed(),
>
> --
> 0-DAY CI Kernel Test Service
> https://01.org/lkp
--
Best Regards
Guo Ren
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