Re: [PATCH v3 2/2] powerpc/fadump: make is_kdump_kernel() return false when fadump is active

[Baoquan He]

On 09/12/23 at 01:59pm, Hari Bathini wrote:
> Currently, is_kdump_kernel() returns true in crash dump capture kernel
> for both kdump and fadump crash dump capturing methods, as both these
> methods set elfcorehdr_addr. Some restrictions enforced for crash dump
> capture kernel, based on is_kdump_kernel(), are specifically meant for
> kdump case and not desirable for fadump - eg. IO queues restriction in
> device drivers. So, define is_kdump_kernel() to return false when f/w
> assisted dump is active.
> 
> Signed-off-by: Hari Bathini 
> ---
>  arch/powerpc/include/asm/kexec.h |  8 ++--
>  arch/powerpc/kernel/crash_dump.c | 12 
>  2 files changed, 18 insertions(+), 2 deletions(-)

LGTM,

Acked-by: Baoquan He 

> 
> diff --git a/arch/powerpc/include/asm/kexec.h 
> b/arch/powerpc/include/asm/kexec.h
> index a1ddba01e7d1..e1b43aa12175 100644
> --- a/arch/powerpc/include/asm/kexec.h
> +++ b/arch/powerpc/include/asm/kexec.h
> @@ -99,10 +99,14 @@ void relocate_new_kernel(unsigned long indirection_page, 
> unsigned long reboot_co
>  
>  void kexec_copy_flush(struct kimage *image);
>  
> -#if defined(CONFIG_CRASH_DUMP) && defined(CONFIG_PPC_RTAS)
> +#if defined(CONFIG_CRASH_DUMP)
> +bool is_kdump_kernel(void);
> +#define is_kdump_kernel  is_kdump_kernel
> +#if defined(CONFIG_PPC_RTAS)
>  void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
>  #define crash_free_reserved_phys_range crash_free_reserved_phys_range
> -#endif
> +#endif /* CONFIG_PPC_RTAS */
> +#endif /* CONFIG_CRASH_DUMP */
>  
>  #ifdef CONFIG_KEXEC_FILE
>  extern const struct kexec_file_ops kexec_elf64_ops;
> diff --git a/arch/powerpc/kernel/crash_dump.c 
> b/arch/powerpc/kernel/crash_dump.c
> index 9a3b85bfc83f..2086fa6cdc25 100644
> --- a/arch/powerpc/kernel/crash_dump.c
> +++ b/arch/powerpc/kernel/crash_dump.c
> @@ -19,6 +19,7 @@
>  #include 
>  #include 
>  #include 
> +#include 
>  
>  #ifdef DEBUG
>  #include 
> @@ -92,6 +93,17 @@ ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned 
> long pfn,
>   return csize;
>  }
>  
> +/*
> + * Return true only when kexec based kernel dump capturing method is used.
> + * This ensures all restritions applied for kdump case are not automatically
> + * applied for fadump case.
> + */
> +bool is_kdump_kernel(void)
> +{
> + return !is_fadump_active() && elfcorehdr_addr != ELFCORE_ADDR_MAX;
> +}
> +EXPORT_SYMBOL_GPL(is_kdump_kernel);
> +
>  #ifdef CONFIG_PPC_RTAS
>  /*
>   * The crashkernel region will almost always overlap the RTAS region, so
> -- 
> 2.41.0
> 

[PATCH v3 2/2] powerpc/fadump: make is_kdump_kernel() return false when fadump is active

[Hari Bathini]

Currently, is_kdump_kernel() returns true in crash dump capture kernel
for both kdump and fadump crash dump capturing methods, as both these
methods set elfcorehdr_addr. Some restrictions enforced for crash dump
capture kernel, based on is_kdump_kernel(), are specifically meant for
kdump case and not desirable for fadump - eg. IO queues restriction in
device drivers. So, define is_kdump_kernel() to return false when f/w
assisted dump is active.

Signed-off-by: Hari Bathini 
---
 arch/powerpc/include/asm/kexec.h |  8 ++--
 arch/powerpc/kernel/crash_dump.c | 12 
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index a1ddba01e7d1..e1b43aa12175 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -99,10 +99,14 @@ void relocate_new_kernel(unsigned long indirection_page, 
unsigned long reboot_co
 
 void kexec_copy_flush(struct kimage *image);
 
-#if defined(CONFIG_CRASH_DUMP) && defined(CONFIG_PPC_RTAS)
+#if defined(CONFIG_CRASH_DUMP)
+bool is_kdump_kernel(void);
+#define is_kdump_kernelis_kdump_kernel
+#if defined(CONFIG_PPC_RTAS)
 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
 #define crash_free_reserved_phys_range crash_free_reserved_phys_range
-#endif
+#endif /* CONFIG_PPC_RTAS */
+#endif /* CONFIG_CRASH_DUMP */
 
 #ifdef CONFIG_KEXEC_FILE
 extern const struct kexec_file_ops kexec_elf64_ops;
diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c
index 9a3b85bfc83f..2086fa6cdc25 100644
--- a/arch/powerpc/kernel/crash_dump.c
+++ b/arch/powerpc/kernel/crash_dump.c
@@ -19,6 +19,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #ifdef DEBUG
 #include 
@@ -92,6 +93,17 @@ ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned 
long pfn,
return csize;
 }
 
+/*
+ * Return true only when kexec based kernel dump capturing method is used.
+ * This ensures all restritions applied for kdump case are not automatically
+ * applied for fadump case.
+ */
+bool is_kdump_kernel(void)
+{
+   return !is_fadump_active() && elfcorehdr_addr != ELFCORE_ADDR_MAX;
+}
+EXPORT_SYMBOL_GPL(is_kdump_kernel);
+
 #ifdef CONFIG_PPC_RTAS
 /*
  * The crashkernel region will almost always overlap the RTAS region, so
-- 
2.41.0