From e94965ed5beb23c6fabf7ed31f625e66d7ff28de Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 15 Dec 2010 14:00:19 -0800 Subject: module: show version information for built-in modules in sysfs 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 --- include/linux/module.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 8b17fd8c790d..50efcd3ae850 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -58,6 +58,12 @@ struct module_attribute { void (*free)(struct module *); }; +struct module_version_attribute { + struct module_attribute mattr; + const char *module_name; + const char *version; +}; + struct module_kobject { struct kobject kobj; @@ -161,7 +167,28 @@ extern struct module __this_module; Using this automatically adds a checksum of the .c files and the local headers in "srcversion". */ + +#ifdef MODULE #define MODULE_VERSION(_version) MODULE_INFO(version, _version) +#else +#define MODULE_VERSION(_version) \ + extern ssize_t __modver_version_show(struct module_attribute *, \ + struct module *, char *); \ + static struct module_version_attribute __modver_version_attr \ + __used \ + __attribute__ ((__section__ ("__modver"),aligned(sizeof(void *)))) \ + = { \ + .mattr = { \ + .attr = { \ + .name = "version", \ + .mode = S_IRUGO, \ + }, \ + .show = __modver_version_show, \ + }, \ + .module_name = KBUILD_MODNAME, \ + .version = _version, \ + } +#endif /* Optional firmware file (or files) needed by the module * format is simply firmware file name. Multiple firmware -- cgit v1.2.3 From 3b90a5b292321b2acac3921f77046ae195aef53f Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 24 Jan 2011 14:32:51 -0600 Subject: module: fix linker error for MODULE_VERSION when !MODULE and CONFIG_SYSFS=n 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 --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 50efcd3ae850..e7c6385c6683 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -168,7 +168,7 @@ extern struct module __this_module; local headers in "srcversion". */ -#ifdef MODULE +#if defined(MODULE) || !defined(CONFIG_SYSFS) #define MODULE_VERSION(_version) MODULE_INFO(version, _version) #else #define MODULE_VERSION(_version) \ -- cgit v1.2.3 From e4a9ea5ee7c8812a7bf0c3fb725ceeaa3d4c2fcc Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 27 Jan 2011 09:15:30 -0500 Subject: tracing: Replace trace_event struct array with pointer array 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 --- include/asm-generic/vmlinux.lds.h | 7 +++---- include/linux/module.h | 2 +- include/linux/syscalls.h | 10 ++++++---- include/trace/ftrace.h | 24 +++++++++++++----------- kernel/trace/trace_events.c | 12 ++++++------ kernel/trace/trace_export.c | 6 +++--- 6 files changed, 32 insertions(+), 29 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 6ebb81030d2d..f53708be95eb 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -124,7 +124,8 @@ #endif #ifdef CONFIG_EVENT_TRACING -#define FTRACE_EVENTS() VMLINUX_SYMBOL(__start_ftrace_events) = .; \ +#define FTRACE_EVENTS() . = ALIGN(8); \ + VMLINUX_SYMBOL(__start_ftrace_events) = .; \ *(_ftrace_events) \ VMLINUX_SYMBOL(__stop_ftrace_events) = .; #else @@ -179,9 +180,6 @@ TRACE_PRINTKS() \ \ STRUCT_ALIGN(); \ - FTRACE_EVENTS() \ - \ - STRUCT_ALIGN(); \ TRACE_SYSCALLS() /* @@ -482,6 +480,7 @@ KERNEL_CTORS() \ *(.init.rodata) \ MCOUNT_REC() \ + FTRACE_EVENTS() \ DEV_DISCARD(init.rodata) \ CPU_DISCARD(init.rodata) \ MEM_DISCARD(init.rodata) \ diff --git a/include/linux/module.h b/include/linux/module.h index e7c6385c6683..7695a303bb55 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -389,7 +389,7 @@ struct module unsigned int num_trace_bprintk_fmt; #endif #ifdef CONFIG_EVENT_TRACING - struct ftrace_event_call *trace_events; + struct ftrace_event_call **trace_events; unsigned int num_trace_events; #endif #ifdef CONFIG_FTRACE_MCOUNT_RECORD diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 18cd0684fc4e..45508fec366d 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -128,28 +128,30 @@ extern struct trace_event_functions exit_syscall_print_funcs; static struct syscall_metadata \ __attribute__((__aligned__(4))) __syscall_meta_##sname; \ static struct ftrace_event_call __used \ - __attribute__((__aligned__(4))) \ - __attribute__((section("_ftrace_events"))) \ event_enter_##sname = { \ .name = "sys_enter"#sname, \ .class = &event_class_syscall_enter, \ .event.funcs = &enter_syscall_print_funcs, \ .data = (void *)&__syscall_meta_##sname,\ }; \ + static struct ftrace_event_call __used \ + __attribute__((section("_ftrace_events"))) \ + *__event_enter_##sname = &event_enter_##sname; \ __TRACE_EVENT_FLAGS(enter_##sname, TRACE_EVENT_FL_CAP_ANY) #define SYSCALL_TRACE_EXIT_EVENT(sname) \ static struct syscall_metadata \ __attribute__((__aligned__(4))) __syscall_meta_##sname; \ static struct ftrace_event_call __used \ - __attribute__((__aligned__(4))) \ - __attribute__((section("_ftrace_events"))) \ event_exit_##sname = { \ .name = "sys_exit"#sname, \ .class = &event_class_syscall_exit, \ .event.funcs = &exit_syscall_print_funcs, \ .data = (void *)&__syscall_meta_##sname,\ }; \ + static struct ftrace_event_call __used \ + __attribute__((section("_ftrace_events"))) \ + *__event_exit_##sname = &event_exit_##sname; \ __TRACE_EVENT_FLAGS(exit_##sname, TRACE_EVENT_FL_CAP_ANY) #define SYSCALL_METADATA(sname, nb) \ diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index e16610c208c9..3e68366d485a 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -446,14 +446,16 @@ static inline notrace int ftrace_get_offsets_##call( \ * .reg = ftrace_event_reg, * }; * - * static struct ftrace_event_call __used - * __attribute__((__aligned__(4))) - * __attribute__((section("_ftrace_events"))) event_ = { + * static struct ftrace_event_call event_ = { * .name = "", * .class = event_class_