Re: [v5 4/6] extable: Add function to search only kernel exception table

2019-07-11 Thread Nicholas Piggin
Santosh Sivaraj's on July 9, 2019 10:15 pm:
> In real mode, the search_exception tables cannot be called because
> it also searches the module exception tables if entry is not found
> in the kernel exception tables.

This is a patch for generic kernel code, it may not go through
powerpc tree and someone doing git blame or something won't have
any idea what this changelog means.

Can you re-word this and just say something like, "certain architecture
$specific operating modes (e.g., in powerpc machine check handler that
is unable to access vmalloc memory)."

> 
> Cc: Thomas Gleixner 
> Cc: Ingo Molnar 
> Cc: Nicholas Piggin 
> Signed-off-by: Santosh Sivaraj 
> ---
>  include/linux/extable.h |  2 ++
>  kernel/extable.c| 16 +---
>  2 files changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/include/linux/extable.h b/include/linux/extable.h
> index 41c5b3a25f67..0c2819ba67f0 100644
> --- a/include/linux/extable.h
> +++ b/include/linux/extable.h
> @@ -19,6 +19,8 @@ void trim_init_extable(struct module *m);
>  
>  /* Given an address, look for it in the exception tables */
>  const struct exception_table_entry *search_exception_tables(unsigned long 
> add);
> +const struct
> +exception_table_entry *search_kernel_exception_table(unsigned long addr);
>  
>  #ifdef CONFIG_MODULES
>  /* For extable.c to search modules' exception tables. */
> diff --git a/kernel/extable.c b/kernel/extable.c
> index e23cce6e6092..6d544cb79fff 100644
> --- a/kernel/extable.c
> +++ b/kernel/extable.c
> @@ -40,13 +40,23 @@ void __init sort_main_extable(void)
>   }
>  }
>  
> -/* Given an address, look for it in the exception tables. */
> +/* For the given address, look for it in the kernel exception table */

Nitpick, no reason to vary the structure of the comment.

Code wise it looks fine, so with the comments and changelog fixed,

Reviewed-by: Nicholas Piggin 

> +const
> +struct exception_table_entry *search_kernel_exception_table(unsigned long 
> addr)
> +{
> + return search_extable(__start___ex_table,
> +   __stop___ex_table - __start___ex_table, addr);
> +}
> +
> +/*
> + * Given an address, look for it in the kernel and the module exception
> + * tables.
> + */
>  const struct exception_table_entry *search_exception_tables(unsigned long 
> addr)
>  {
>   const struct exception_table_entry *e;
>  
> - e = search_extable(__start___ex_table,
> -__stop___ex_table - __start___ex_table, addr);
> + e = search_kernel_exception_table(addr);
>   if (!e)
>   e = search_module_extables(addr);
>   return e;
> -- 
> 2.20.1
> 
> 


[v5 4/6] extable: Add function to search only kernel exception table

2019-07-09 Thread Santosh Sivaraj
In real mode, the search_exception tables cannot be called because
it also searches the module exception tables if entry is not found
in the kernel exception tables.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Nicholas Piggin 
Signed-off-by: Santosh Sivaraj 
---
 include/linux/extable.h |  2 ++
 kernel/extable.c| 16 +---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/linux/extable.h b/include/linux/extable.h
index 41c5b3a25f67..0c2819ba67f0 100644
--- a/include/linux/extable.h
+++ b/include/linux/extable.h
@@ -19,6 +19,8 @@ void trim_init_extable(struct module *m);
 
 /* Given an address, look for it in the exception tables */
 const struct exception_table_entry *search_exception_tables(unsigned long add);
+const struct
+exception_table_entry *search_kernel_exception_table(unsigned long addr);
 
 #ifdef CONFIG_MODULES
 /* For extable.c to search modules' exception tables. */
diff --git a/kernel/extable.c b/kernel/extable.c
index e23cce6e6092..6d544cb79fff 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -40,13 +40,23 @@ void __init sort_main_extable(void)
}
 }
 
-/* Given an address, look for it in the exception tables. */
+/* For the given address, look for it in the kernel exception table */
+const
+struct exception_table_entry *search_kernel_exception_table(unsigned long addr)
+{
+   return search_extable(__start___ex_table,
+ __stop___ex_table - __start___ex_table, addr);
+}
+
+/*
+ * Given an address, look for it in the kernel and the module exception
+ * tables.
+ */
 const struct exception_table_entry *search_exception_tables(unsigned long addr)
 {
const struct exception_table_entry *e;
 
-   e = search_extable(__start___ex_table,
-  __stop___ex_table - __start___ex_table, addr);
+   e = search_kernel_exception_table(addr);
if (!e)
e = search_module_extables(addr);
return e;
-- 
2.20.1