On Tue, 2011-01-18 at 11:46 -0500, Mathieu Desnoyers wrote:
> * David Miller (da...@davemloft.net) wrote:
> > From: David Miller <da...@davemloft.net>
> > Date: Mon, 17 Jan 2011 22:00:39 -0800 (PST)
> > 
> > > ftrace: Remove unnecessary alignment tag from ftrace_event_call.
> > > 
> > > It's completely unnecessary and causes problems on platforms
> > > where this tag down-aligns the structure's alignment.
> > > 
> > > Signed-off-by: David S. Miller <da...@davemloft.net>
> >  ...
> > 
> > Ok, unless we can explain why these alignments are needed at all, we
> > should kill all of them:
> 
> ftrace: linker script add missing struct align
> 
> We should add the missing "STRUCT_ALIGN();" in
> include/asm-generic/vmlinux.lds.h as a preliminary step to remove the ftrace
> bogus structure alignments. Moving all STRUCT_ALIGN() for FTRACE_EVENTS()
> and TRACE_SYSCALLS() into the definitions, so the alignment is only done if
> these infrastructures are configured in. 
> 
> Also align TRACE_PRINTKS on 8 bytes to make sure the beginning of the section 
> is
> aligned on pointer size.

If I can make it crash without the alignments and this fixes the issue,
I'll apply both patches.

Thanks,

-- Steve

> 
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> ---
>  include/asm-generic/vmlinux.lds.h |   19 ++++++++++---------
>  1 file changed, 10 insertions(+), 9 deletions(-)
> 
> Index: linux-2.6-lttng/include/asm-generic/vmlinux.lds.h
> ===================================================================
> --- linux-2.6-lttng.orig/include/asm-generic/vmlinux.lds.h
> +++ linux-2.6-lttng/include/asm-generic/vmlinux.lds.h
> @@ -107,7 +107,8 @@
>  #endif
>  
>  #ifdef CONFIG_TRACE_BRANCH_PROFILING
> -#define LIKELY_PROFILE()     
> VMLINUX_SYMBOL(__start_annotated_branch_profile) = .; \
> +#define LIKELY_PROFILE()     STRUCT_ALIGN();                                 
>       \
> +                             
> VMLINUX_SYMBOL(__start_annotated_branch_profile) = .; \
>                               *(_ftrace_annotated_branch)                     
>       \
>                               VMLINUX_SYMBOL(__stop_annotated_branch_profile) 
> = .;
>  #else
> @@ -115,7 +116,8 @@
>  #endif
>  
>  #ifdef CONFIG_PROFILE_ALL_BRANCHES
> -#define BRANCH_PROFILE()     VMLINUX_SYMBOL(__start_branch_profile) = .;   \
> +#define BRANCH_PROFILE()     STRUCT_ALIGN();                               \
> +                             VMLINUX_SYMBOL(__start_branch_profile) = .;   \
>                               *(_ftrace_branch)                             \
>                               VMLINUX_SYMBOL(__stop_branch_profile) = .;
>  #else
> @@ -123,7 +125,8 @@
>  #endif
>  
>  #ifdef CONFIG_EVENT_TRACING
> -#define FTRACE_EVENTS()      VMLINUX_SYMBOL(__start_ftrace_events) = .;      
> \
> +#define FTRACE_EVENTS()      STRUCT_ALIGN();                                 
> \
> +                     VMLINUX_SYMBOL(__start_ftrace_events) = .;      \
>                       *(_ftrace_events)                               \
>                       VMLINUX_SYMBOL(__stop_ftrace_events) = .;
>  #else
> @@ -131,7 +134,8 @@
>  #endif
>  
>  #ifdef CONFIG_TRACING
> -#define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .;     
>  \
> +#define TRACE_PRINTKS()  . = ALIGN(8);                                       
>        \
> +                      VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .;      \
>                        *(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \
>                        VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .;
>  #else
> @@ -139,7 +143,8 @@
>  #endif
>  
>  #ifdef CONFIG_FTRACE_SYSCALLS
> -#define TRACE_SYSCALLS() VMLINUX_SYMBOL(__start_syscalls_metadata) = .;      
> \
> +#define TRACE_SYSCALLS() STRUCT_ALIGN();                             \
> +                      VMLINUX_SYMBOL(__start_syscalls_metadata) = .; \
>                        *(__syscalls_metadata)                         \
>                        VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
>  #else
> @@ -169,11 +174,7 @@
>       LIKELY_PROFILE()                                                \
>       BRANCH_PROFILE()                                                \
>       TRACE_PRINTKS()                                                 \
> -                                                                     \
> -     STRUCT_ALIGN();                                                 \
>       FTRACE_EVENTS()                                                 \
> -                                                                     \
> -     STRUCT_ALIGN();                                                 \
>       TRACE_SYSCALLS()
>  
>  /*
> 
> 
> 





-- 
To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org

Reply via email to