On Wed 2017-12-06 13:36:49, Sergey Senozhatsky wrote:
> Hello,
>
> so we got a number of build-error reports [somehow I
> thought 0day has compile tested the patches already; well, I
> was wrong] basically on congifs that have no KALLSYMS.
>
>
> Petr, can we replace 0006 with the following patch?
Done. See comments below.
> From: Sergey Senozhatsky <sergey.senozhat...@gmail.com>
> Subject: [PATCH] symbol lookup: introduce dereference_symbol_descriptor()
>
>
> Signed-off-by: Sergey Senozhatsky <sergey.senozhat...@gmail.com>
The new patch only shuffled the code to fix a compilation problem
with CONFIG_CALLSYMS undefined. It did not change the functionality.
Therefore I put back:
Tested-by: Tony Luck <tony.l...@intel.com> #ia64
Tested-by: Santosh Sivaraj <sant...@fossix.org> #powerpc
Tested-by: Helge Deller <del...@gmx.de> #parisc64
> ---
> Documentation/printk-formats.txt | 42 ++++++++++++-------------------
> include/linux/kallsyms.h | 53
> ++++++++++++++++++++++++++++++++++++++++
> kernel/kallsyms.c | 33 -------------------------
> lib/vsprintf.c | 5 ++--
> 4 files changed, 71 insertions(+), 62 deletions(-)
>
> diff --git a/Documentation/printk-formats.txt
> b/Documentation/printk-formats.txt
> index aa0a776c817a..02745028e909 100644
> --- a/Documentation/printk-formats.txt
> +++ b/Documentation/printk-formats.txt
> @@ -61,41 +61,31 @@ Symbols/Function Pointers
>
> ::
>
> - %pF versatile_init+0x0/0x110
> - %pf versatile_init
> - %pS versatile_init+0x0/0x110
> - %pSR versatile_init+0x9/0x110
> + %pS versatile_init+0x0/0x110
> + %ps versatile_init
> + %pF versatile_init+0x0/0x110
> + %pf versatile_init
> + %pSR versatile_init+0x9/0x110
> (with __builtin_extract_return_addr() translation)
> - %ps versatile_init
> - %pB prev_fn_of_versatile_init+0x88/0x88
> + %pB prev_fn_of_versatile_init+0x88/0x88
I was curious why so many lines were changed here. You converted
the 2nd tab to spaces. I put back the tab. The result is:
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -50,42 +50,31 @@ Symbols/Function Pointers
::
+ %pS versatile_init+0x0/0x110
+ %ps versatile_init
%pF versatile_init+0x0/0x110
%pf versatile_init
- %pS versatile_init+0x0/0x110
%pSR versatile_init+0x9/0x110
(with __builtin_extract_return_addr() translation)
- %ps versatile_init
%pB prev_fn_of_versatile_init+0x88/0x88
https://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk.git/commit/?h=for-4.16-deprecate-printk-pf&id=78675fe41d57c2bf9cb671f0a85b369a5a156f0a
>
> diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
> index bd118a6c60cb..1bcfe221e62c 100644
> --- a/include/linux/kallsyms.h
> +++ b/include/linux/kallsyms.h
> +static inline void *dereference_symbol_descriptor(void *ptr)
> +{
> +#ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR
> + struct module *mod;
> +
> + ptr = dereference_kernel_function_descriptor(ptr);
> + if (is_ksym_addr((unsigned long)ptr))
> + return ptr;
> +
> + preempt_disable();
> + mod = __module_address((unsigned long)ptr);
> + preempt_enable();
> +
> + if (mod)
> + ptr = dereference_module_function_descriptor(mod, ptr);
> +#endif
> + return ptr;
> +}
It is a bit too long for an inline function but I did not find a
better solution. It should always be defined and all suitable
.c files are compiled only under certain configuration. Well,
it is a nop on most architectures.
Best Regards,
Petr
