Re: [PATCH v17 1/6] crash: forward memory_notify arg to arch crash hotplug handler

2024-03-02 Thread Hari Bathini




On 26/02/24 2:11 pm, Sourabh Jain wrote:

In the event of memory hotplug or online/offline events, the crash
memory hotplug notifier `crash_memhp_notifier()` receives a
`memory_notify` object but doesn't forward that object to the
generic and architecture-specific crash hotplug handler.

The `memory_notify` object contains the starting PFN (Page Frame Number)
and the number of pages in the hot-removed memory. This information is
necessary for architectures like PowerPC to update/recreate the kdump
image, specifically `elfcorehdr`.

So update the function signature of `crash_handle_hotplug_event()` and
`arch_crash_handle_hotplug_event()` to accept the `memory_notify` object
as an argument from crash memory hotplug notifier.

Since no such object is available in the case of CPU hotplug event, the
crash CPU hotplug notifier `crash_cpuhp_online()` passes NULL to the
crash hotplug handler.



Acked-by: Hari Bathini 


Signed-off-by: Sourabh Jain 
Acked-by: Baoquan He 
Cc: Akhil Raj 
Cc: Andrew Morton 
Cc: Aneesh Kumar K.V 
Cc: Borislav Petkov (AMD) 
Cc: Boris Ostrovsky 
Cc: Christophe Leroy 
Cc: Dave Hansen 
Cc: Dave Young 
Cc: David Hildenbrand 
Cc: Greg Kroah-Hartman 
Cc: Hari Bathini 
Cc: Laurent Dufour 
Cc: Mahesh Salgaonkar 
Cc: Michael Ellerman 
Cc: Mimi Zohar 
Cc: Naveen N Rao 
Cc: Oscar Salvador 
Cc: Thomas Gleixner 
Cc: Valentin Schneider 
Cc: Vivek Goyal 
Cc: ke...@lists.infradead.org
Cc: x...@kernel.org
---
  arch/x86/include/asm/kexec.h |  2 +-
  arch/x86/kernel/crash.c  |  4 +++-
  include/linux/crash_core.h   |  2 +-
  kernel/crash_core.c  | 14 +++---
  4 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 91ca9a9ee3a2..cb1320ebbc23 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -207,7 +207,7 @@ int arch_kimage_file_post_load_cleanup(struct kimage 
*image);
  extern void kdump_nmi_shootdown_cpus(void);
  
  #ifdef CONFIG_CRASH_HOTPLUG

-void arch_crash_handle_hotplug_event(struct kimage *image);
+void arch_crash_handle_hotplug_event(struct kimage *image, void *arg);
  #define arch_crash_handle_hotplug_event arch_crash_handle_hotplug_event
  
  #ifdef CONFIG_HOTPLUG_CPU

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index e74d0c4286c1..2a682fe86352 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -432,10 +432,12 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
  /**
   * arch_crash_handle_hotplug_event() - Handle hotplug elfcorehdr changes
   * @image: a pointer to kexec_crash_image
+ * @arg: struct memory_notify handler for memory hotplug case and
+ *   NULL for CPU hotplug case.
   *
   * Prepare the new elfcorehdr and replace the existing elfcorehdr.
   */
-void arch_crash_handle_hotplug_event(struct kimage *image)
+void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
  {
void *elfbuf = NULL, *old_elfcorehdr;
unsigned long nr_mem_ranges;
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index d33352c2e386..647e928efee8 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -37,7 +37,7 @@ static inline void arch_kexec_unprotect_crashkres(void) { }
  
  
  #ifndef arch_crash_handle_hotplug_event

-static inline void arch_crash_handle_hotplug_event(struct kimage *image) { }
+static inline void arch_crash_handle_hotplug_event(struct kimage *image, void 
*arg) { }
  #endif
  
  int crash_check_update_elfcorehdr(void);

diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 78b5dc7cee3a..70fa8111a9d6 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -534,7 +534,7 @@ int crash_check_update_elfcorehdr(void)
   * list of segments it checks (since the elfcorehdr changes and thus
   * would require an update to purgatory itself to update the digest).
   */
-static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int 
cpu)
+static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int 
cpu, void *arg)
  {
struct kimage *image;
  
@@ -596,7 +596,7 @@ static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu)

image->hp_action = hp_action;
  
  	/* Now invoke arch-specific update handler */

-   arch_crash_handle_hotplug_event(image);
+   arch_crash_handle_hotplug_event(image, arg);
  
  	/* No longer handling a hotplug event */

image->hp_action = KEXEC_CRASH_HP_NONE;
@@ -612,17 +612,17 @@ static void crash_handle_hotplug_event(unsigned int 
hp_action, unsigned int cpu)
crash_hotplug_unlock();
  }
  
-static int crash_memhp_notifier(struct notifier_block *nb, unsigned long val, void *v)

+static int crash_memhp_notifier(struct notifier_block *nb, unsigned long val, 
void *arg)
  {
switch (val) {
case MEM_ONLINE:
crash_handle_hotplug_event(KEXEC_CRASH_HP_ADD_MEMORY,
-   KEXEC_CRASH_HP_INVALID_CPU);
+  

[PATCH v17 1/6] crash: forward memory_notify arg to arch crash hotplug handler

2024-02-26 Thread Sourabh Jain
In the event of memory hotplug or online/offline events, the crash
memory hotplug notifier `crash_memhp_notifier()` receives a
`memory_notify` object but doesn't forward that object to the
generic and architecture-specific crash hotplug handler.

The `memory_notify` object contains the starting PFN (Page Frame Number)
and the number of pages in the hot-removed memory. This information is
necessary for architectures like PowerPC to update/recreate the kdump
image, specifically `elfcorehdr`.

So update the function signature of `crash_handle_hotplug_event()` and
`arch_crash_handle_hotplug_event()` to accept the `memory_notify` object
as an argument from crash memory hotplug notifier.

Since no such object is available in the case of CPU hotplug event, the
crash CPU hotplug notifier `crash_cpuhp_online()` passes NULL to the
crash hotplug handler.

Signed-off-by: Sourabh Jain 
Acked-by: Baoquan He 
Cc: Akhil Raj 
Cc: Andrew Morton 
Cc: Aneesh Kumar K.V 
Cc: Borislav Petkov (AMD) 
Cc: Boris Ostrovsky 
Cc: Christophe Leroy 
Cc: Dave Hansen 
Cc: Dave Young 
Cc: David Hildenbrand 
Cc: Greg Kroah-Hartman 
Cc: Hari Bathini 
Cc: Laurent Dufour 
Cc: Mahesh Salgaonkar 
Cc: Michael Ellerman 
Cc: Mimi Zohar 
Cc: Naveen N Rao 
Cc: Oscar Salvador 
Cc: Thomas Gleixner 
Cc: Valentin Schneider 
Cc: Vivek Goyal 
Cc: ke...@lists.infradead.org
Cc: x...@kernel.org
---
 arch/x86/include/asm/kexec.h |  2 +-
 arch/x86/kernel/crash.c  |  4 +++-
 include/linux/crash_core.h   |  2 +-
 kernel/crash_core.c  | 14 +++---
 4 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 91ca9a9ee3a2..cb1320ebbc23 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -207,7 +207,7 @@ int arch_kimage_file_post_load_cleanup(struct kimage 
*image);
 extern void kdump_nmi_shootdown_cpus(void);
 
 #ifdef CONFIG_CRASH_HOTPLUG
-void arch_crash_handle_hotplug_event(struct kimage *image);
+void arch_crash_handle_hotplug_event(struct kimage *image, void *arg);
 #define arch_crash_handle_hotplug_event arch_crash_handle_hotplug_event
 
 #ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index e74d0c4286c1..2a682fe86352 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -432,10 +432,12 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
 /**
  * arch_crash_handle_hotplug_event() - Handle hotplug elfcorehdr changes
  * @image: a pointer to kexec_crash_image
+ * @arg: struct memory_notify handler for memory hotplug case and
+ *   NULL for CPU hotplug case.
  *
  * Prepare the new elfcorehdr and replace the existing elfcorehdr.
  */
-void arch_crash_handle_hotplug_event(struct kimage *image)
+void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
 {
void *elfbuf = NULL, *old_elfcorehdr;
unsigned long nr_mem_ranges;
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index d33352c2e386..647e928efee8 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -37,7 +37,7 @@ static inline void arch_kexec_unprotect_crashkres(void) { }
 
 
 #ifndef arch_crash_handle_hotplug_event
-static inline void arch_crash_handle_hotplug_event(struct kimage *image) { }
+static inline void arch_crash_handle_hotplug_event(struct kimage *image, void 
*arg) { }
 #endif
 
 int crash_check_update_elfcorehdr(void);
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 78b5dc7cee3a..70fa8111a9d6 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -534,7 +534,7 @@ int crash_check_update_elfcorehdr(void)
  * list of segments it checks (since the elfcorehdr changes and thus
  * would require an update to purgatory itself to update the digest).
  */
-static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int 
cpu)
+static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int 
cpu, void *arg)
 {
struct kimage *image;
 
@@ -596,7 +596,7 @@ static void crash_handle_hotplug_event(unsigned int 
hp_action, unsigned int cpu)
image->hp_action = hp_action;
 
/* Now invoke arch-specific update handler */
-   arch_crash_handle_hotplug_event(image);
+   arch_crash_handle_hotplug_event(image, arg);
 
/* No longer handling a hotplug event */
image->hp_action = KEXEC_CRASH_HP_NONE;
@@ -612,17 +612,17 @@ static void crash_handle_hotplug_event(unsigned int 
hp_action, unsigned int cpu)
crash_hotplug_unlock();
 }
 
-static int crash_memhp_notifier(struct notifier_block *nb, unsigned long val, 
void *v)
+static int crash_memhp_notifier(struct notifier_block *nb, unsigned long val, 
void *arg)
 {
switch (val) {
case MEM_ONLINE:
crash_handle_hotplug_event(KEXEC_CRASH_HP_ADD_MEMORY,
-   KEXEC_CRASH_HP_INVALID_CPU);
+   KEXEC_CRASH_HP_INVALID_CPU, arg);
break;
 
case MEM_OFFLINE