user/sven/linux.git/include/linux/module.h, branch v3.0.85

module: Sort exported symbols

2011-05-19T07:25:27Z

This patch places every exported symbol in its own section (i.e. "___ksymtab+printk"). Thus the linker will use its SORT() directive to sort and finally merge all symbol in the right and final section (i.e. "__ksymtab"). The symbol prefixed archs use an underscore as prefix for symbols. To avoid collision we use a different character to create the temporary section names. This work was supported by a hardware donation from the CE Linux Forum. Signed-off-by: Alessio Igor Bogani Signed-off-by: Rusty Russell (folded in '+' fixup) Tested-by: Dirk Behme

module: each_symbol_section instead of each_symbol

2011-05-19T07:25:26Z

Instead of having a callback function for each symbol in the kernel, have a callback for each array of symbols. This eases the logic when we move to sorted symbols and binary search. Signed-off-by: Rusty Russell Signed-off-by: Alessio Igor Bogani

module: remove 64 bit alignment padding from struct module with CONFIG_TRACE*

2011-05-19T07:25:25Z

Reorder struct module to remove 24 bytes of alignment padding on 64 bit builds when the CONFIG_TRACE options are selected. This allows the structure to fit into one fewer cache lines, and its size drops from 592 to 568 on x86_64. Signed-off-by: Richard Kennedy Signed-off-by: Rusty Russell

module: do not hide __modver_version_show declaration behind ifdef

2011-05-19T07:25:25Z

Doing so prevents the following warning from sparse: CHECK kernel/params.c kernel/params.c:817:9: warning: symbol '__modver_version_show' was not declared. Should it be static? since kernel/params.c is never compiled with MODULE being set. Signed-off-by: Dmitry Torokhov Signed-off-by: Rusty Russell

module: deal with alignment issues in built-in module versions

2011-05-19T07:25:24Z

On m68k natural alignment is 2-byte boundary but we are trying to align structures in __modver section on sizeof(void *) boundary. This causes trouble when we try to access elements in this section in array-like fashion when create "version" attributes for built-in modules. Moreover, as DaveM said, we can't reliably put structures into independent objects, put them into a special section, and then expect array access over them (via the section boundaries) after linking the objects together to just "work" due to variable alignment choices in different situations. The only solution that seems to work reliably is to make an array of plain pointers to the objects in question and put those pointers in the special section. Reported-by: Geert Uytterhoeven Signed-off-by: Dmitry Torokhov Signed-off-by: Rusty Russell

module: explicitly align module_version_attribute structure

2011-02-21T23:21:53Z

We force particular alignment when we generate attribute structures when generation MODULE_VERSION() data and we need to make sure that this alignment is followed when we iterate over these structures, otherwise we may crash on platforms whose natural alignment is not sizeof(void *), such as m68k. Reported-by: Geert Uytterhoeven Signed-off-by: Dmitry Torokhov [ There are more issues here, but the fixes are incredibly ugly - Linus ] Signed-off-by: Linus Torvalds

tracepoints: Fix section alignment using pointer array

2011-02-03T14:28:46Z

Make the tracepoints more robust, making them solid enough to handle compiler changes by not relying on anything based on compiler-specific behavior with respect to structure alignment. Implement an approach proposed by David Miller: use an array of const pointers to refer to the individual structures, and export this pointer array through the linker script rather than the structures per se. It will consume 32 extra bytes per tracepoint (24 for structure padding and 8 for the pointers), but are less likely to break due to compiler changes. History: commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() added the aligned(32) type and variable attribute to the tracepoint structures to deal with gcc happily aligning statically defined structures on 32-byte multiples. One attempt was to use a 8-byte alignment for tracepoint structures by applying both the variable and type attribute to tracepoint structures definitions and declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5. The reason is that the "aligned" attribute only specify the _minimum_ alignment for a structure, leaving both the compiler and the linker free to align on larger multiples. Because tracepoint.c expects the structures to be placed as an array within each section, up-alignment cause NULL-pointer exceptions due to the extra unexpected padding. (this patch applies on top of -tip) Signed-off-by: Mathieu Desnoyers Acked-by: David S. Miller LKML-Reference: <20110126222622.GA10794@Krystal> CC: Frederic Weisbecker CC: Ingo Molnar CC: Thomas Gleixner CC: Andrew Morton CC: Peter Zijlstra CC: Rusty Russell Signed-off-by: Steven Rostedt

tracing: Replace trace_event struct array with pointer array

2011-02-03T02:37:13Z

Currently the trace_event structures are placed in the _ftrace_events section, and at link time, the linker makes one large array of all the trace_event structures. On boot up, this array is read (much like the initcall sections) and the events are processed. The problem is that there is no guarantee that gcc will place complex structures nicely together in an array format. Two structures in the same file may be placed awkwardly, because gcc has no clue that they are suppose to be in an array. A hack was used previous to force the alignment to 4, to pack the structures together. But this caused alignment issues with other architectures (sparc). Instead of packing the structures into an array, the structures' addresses are now put into the _ftrace_event section. As pointers are always the natural alignment, gcc should always pack them tightly together (otherwise initcall, extable, etc would also fail). By having the pointers to the structures in the section, we can still iterate the trace_events without causing unnecessary alignment problems with other architectures, or depending on the current behaviour of gcc that will likely change in the future just to tick us kernel developers off a little more. The _ftrace_event section is also moved into the .init.data section as it is now only needed at boot up. Suggested-by: David Miller Cc: Mathieu Desnoyers Acked-by: David S. Miller Signed-off-by: Steven Rostedt

module: fix linker error for MODULE_VERSION when !MODULE and CONFIG_SYSFS=n

2011-01-24T04:02:52Z

lib/built-in.o:(__modver+0x8): undefined reference to `__modver_version_show' lib/built-in.o:(__modver+0x2c): undefined reference to `__modver_version_show' Simplest to just not emit anything: if they've disabled SYSFS they probably want the smallest kernel possible. Reported-by: Randy Dunlap Signed-off-by: Rusty Russell

module: show version information for built-in modules in sysfs

2011-01-24T04:02:51Z

Currently only drivers that are built as modules have their versions shown in /sys/module//version, but this information might also be useful for built-in drivers as well. This especially important for drivers that do not define any parameters - such drivers, if built-in, are completely invisible from userspace. This patch changes MODULE_VERSION() macro so that in case when we are compiling built-in module, version information is stored in a separate section. Kernel then uses this data to create 'version' sysfs attribute in the same fashion it creates attributes for module parameters. Signed-off-by: Dmitry Torokhov Signed-off-by: Rusty Russell