From b99b87f70c7785ab1e253c6220f4b0b57ce3a7f7 Mon Sep 17 00:00:00 2001 From: Peter Oberparleiter Date: Wed, 17 Jun 2009 16:28:03 -0700 Subject: kernel: constructor support Call constructors (gcc-generated initcall-like functions) during kernel start and module load. Constructors are e.g. used for gcov data initialization. Disable constructor support for usermode Linux to prevent conflicts with host glibc. Signed-off-by: Peter Oberparleiter Acked-by: Rusty Russell Acked-by: WANG Cong Cc: Sam Ravnborg Cc: Jeff Dike Cc: Andi Kleen Cc: Huang Ying Cc: Li Wei Cc: Michael Ellerman Cc: Ingo Molnar Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/module.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 215aaab09e91..38928fcaff2b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2216,6 +2216,10 @@ static noinline struct module *load_module(void __user *umod, mod->unused_gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl"); #endif +#ifdef CONFIG_CONSTRUCTORS + mod->ctors = section_objs(hdr, sechdrs, secstrings, ".ctors", + sizeof(*mod->ctors), &mod->num_ctors); +#endif #ifdef CONFIG_MARKERS mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers", @@ -2389,6 +2393,17 @@ static noinline struct module *load_module(void __user *umod, goto free_hdr; } +/* Call module constructors. */ +static void do_mod_ctors(struct module *mod) +{ +#ifdef CONFIG_CONSTRUCTORS + unsigned long i; + + for (i = 0; i < mod->num_ctors; i++) + mod->ctors[i](); +#endif +} + /* This is where the real work happens */ SYSCALL_DEFINE3(init_module, void __user *, umod, unsigned long, len, const char __user *, uargs) @@ -2417,6 +2432,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod); + do_mod_ctors(mod); /* Start the module */ if (mod->init != NULL) ret = do_one_initcall(mod->init); -- cgit v1.2.3 From ad361c9884e809340f6daca80d56a9e9c871690a Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Mon, 6 Jul 2009 13:05:40 -0700 Subject: Remove multiple KERN_ prefixes from printk formats Commit 5fd29d6ccbc98884569d6f3105aeca70858b3e0f ("printk: clean up handling of log-levels and newlines") changed printk semantics. printk lines with multiple KERN_ prefixes are no longer emitted as before the patch. is now included in the output on each additional use. Remove all uses of multiple KERN_s in formats. Signed-off-by: Joe Perches Signed-off-by: Linus Torvalds --- kernel/module.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 38928fcaff2b..0a049837008e 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2451,9 +2451,9 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, return ret; } if (ret > 0) { - printk(KERN_WARNING "%s: '%s'->init suspiciously returned %d, " - "it should follow 0/-E convention\n" - KERN_WARNING "%s: loading module anyway...\n", + printk(KERN_WARNING +"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n" +"%s: loading module anyway...\n", __func__, mod->name, ret, __func__); dump_stack(); -- cgit v1.2.3 From 6560dc160f3a96b8f1f43e2c6b51aa6eb9898b90 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Thu, 23 Jul 2009 23:42:08 +0930 Subject: module: use MODULE_SYMBOL_PREFIX with module_layout The check_modstruct_version() needs to look up the symbol "module_layout" in the kernel, but it does so literally and not by a C identifier. The trouble is that it does not include a symbol prefix for those ports that need it (like the Blackfin and H8300 port). So make sure we tack on the MODULE_SYMBOL_PREFIX define to the front of it. Signed-off-by: Mike Frysinger Signed-off-by: Rusty Russell Signed-off-by: Linus Torvalds --- kernel/module.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 0a049837008e..fd1411403558 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1068,7 +1068,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs, { const unsigned long *crc; - if (!find_symbol("module_layout", NULL, &crc, true, false)) + if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL, + &crc, true, false)) BUG(); return check_version(sechdrs, versindex, "module_layout", mod, crc); } -- cgit v1.2.3 From 7ead8b8313d92b3a69a1a61b0dcbc4cd66c960dc Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 17 Aug 2009 16:56:28 +0800 Subject: tracing/events: Add module tracepoints Add trace points to trace module_load, module_free, module_get, module_put and module_request, and use trace_event facility to get the trace output. Here's the sample output: TASK-PID CPU# TIMESTAMP FUNCTION | | | | | <...>-42 [000] 1.758380: module_request: fb0 wait=1 call_site=fb_open ... <...>-60 [000] 3.269403: module_load: scsi_wait_scan <...>-60 [000] 3.269432: module_put: scsi_wait_scan call_site=sys_init_module refcnt=0 <...>-61 [001] 3.273168: module_free: scsi_wait_scan ... <...>-1021 [000] 13.836081: module_load: sunrpc <...>-1021 [000] 13.840589: module_put: sunrpc call_site=sys_init_module refcnt=-1 <...>-1027 [000] 13.848098: module_get: sunrpc call_site=try_module_get refcnt=0 <...>-1027 [000] 13.848308: module_get: sunrpc call_site=get_filesystem refcnt=1 <...>-1027 [000] 13.848692: module_put: sunrpc call_site=put_filesystem refcnt=0 ... modprobe-2587 [001] 1088.437213: module_load: trace_events_sample F modprobe-2587 [001] 1088.437786: module_put: trace_events_sample call_site=sys_init_module refcnt=0 Note: - the taints flag can be 'F', 'C' and/or 'P' if mod->taints != 0 - the module refcnt is percpu, so it can be negative in a specific cpu Signed-off-by: Li Zefan Acked-by: Rusty Russell Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Rusty Russell LKML-Reference: <4A891B3C.5030608@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/module.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index fd1411403558..b1821438694e 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -55,6 +55,11 @@ #include #include +#define CREATE_TRACE_POINTS +#include + +EXPORT_TRACEPOINT_SYMBOL(module_get); + #if 0 #define DEBUGP printk #else @@ -940,6 +945,8 @@ void module_put(struct module *module) if (module) { unsigned int cpu = get_cpu(); local_dec(__module_ref_addr(module, cpu)); + trace_module_put(module, _RET_IP_, + local_read(__module_ref_addr(module, cpu))); /* Maybe they're waiting for us to drop reference? */ if (unlikely(!module_is_live(module))) wake_up_process(module->waiter); @@ -1491,6 +1498,8 @@ static int __unlink_module(void *_mod) /* Free a module, remove from lists, etc (must hold module_mutex). */ static void free_module(struct module *mod) { + trace_module_free(mod); + /* Delete from various lists */ stop_machine(__unlink_module, mod, NULL); remove_notes_attrs(mod); @@ -2358,6 +2367,8 @@ static noinline struct module *load_module(void __user *umod, /* Get rid of temporary copy */ vfree(hdr); + trace_module_load(mod); + /* Done! */ return mod; -- cgit v1.2.3 From 7d1d16e416e61aeef8655d542f8e4a4fc6e808e4 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 26 Aug 2009 22:02:54 +0930 Subject: module: fix BUG_ON() for powerpc (and other function descriptor archs) The rarely-used symbol_put_addr() needs to use dereference_function_descriptor on powerpc. Reported-by: Paul Mackerras Signed-off-by: Rusty Russell --- kernel/module.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index fd1411403558..07c80e68a6c4 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -909,16 +909,18 @@ void __symbol_put(const char *symbol) } EXPORT_SYMBOL(__symbol_put); +/* Note this assumes addr is a function, which it currently always is. */ void symbol_put_addr(void *addr) { struct module *modaddr; + unsigned long a = (unsigned long)dereference_function_descriptor(addr); - if (core_kernel_text((unsigned long)addr)) + if (core_kernel_text(a)) return; /* module_text_address is safe here: we're supposed to have reference * to module from symbol_get, so it can't go away. */ - modaddr = __module_text_address((unsigned long)addr); + modaddr = __module_text_address(a); BUG_ON(!modaddr); module_put(modaddr); } -- cgit v1.2.3 From 1b364bf438cf337a3818aee77d68c0713f3e1fc4 Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Wed, 26 Aug 2009 22:04:12 +0930 Subject: module: workaround duplicate section names The root cause is a duplicate section name (.text); is this legal? [ Amerigo Wang: "AFAIK, yes." ] However, there's a problem with commit 6d76013381ed28979cd122eb4b249a88b5e384fa in that if you fail to allocate a mod->sect_attrs (in this case it's null because of the duplication), it still gets used without checking in add_notes_attrs() This should fix it [ This patch leaves other problems, particularly the sections directory, but recent parisc toolchains seem to produce these modules and this prevents a crash and is a minimal change -- RR ] Signed-off-by: James Bottomley Signed-off-by: Rusty Russell Tested-by: Helge Deller Signed-off-by: Linus Torvalds --- kernel/module.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 07c80e68a6c4..eccb561dd8a3 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2355,7 +2355,8 @@ static noinline struct module *load_module(void __user *umod, if (err < 0) goto unlink; add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); - add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs); + if (mod->sect_attrs) + add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs); /* Get rid of temporary copy */ vfree(hdr); -- cgit v1.2.3 From ea6bff368548d79529421a9dc0710fc5330eb504 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 28 Aug 2009 10:44:56 +0200 Subject: modules: Fix build error in the !CONFIG_KALLSYMS case MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit > James Bottomley (1): > module: workaround duplicate section names -tip testing found that this patch breaks the build on x86 if CONFIG_KALLSYMS is disabled: kernel/module.c: In function ‘load_module’: kernel/module.c:2367: error: ‘struct module’ has no member named ‘sect_attrs’ distcc[8269] ERROR: compile kernel/module.c on ph/32 failed make[1]: *** [kernel/module.o] Error 1 make: *** [kernel] Error 2 make: *** Waiting for unfinished jobs.... Commit 1b364bf misses the fact that section attributes are only built and dealt with if kallsyms is enabled. The patch below fixes this. ( note, technically speaking this should depend on CONFIG_SYSFS as well but this patch is correct too and keeps the #ifdef less intrusive - in the KALLSYMS && !SYSFS case the code is a NOP. ) Signed-off-by: Ingo Molnar [ Replaced patch with a slightly cleaner variation by James Bottomley ] Signed-off-by: Linus Torvalds --- kernel/module.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index eccb561dd8a3..2d537186191f 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1274,6 +1274,10 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect, struct module_notes_attrs *notes_attrs; struct bin_attribute *nattr; + /* failed to create section attributes, so can't create notes */ + if (!mod->sect_attrs) + return; + /* Count notes sections and allocate structures. */ notes = 0; for (i = 0; i < nsect; i++) @@ -2355,8 +2359,7 @@ static noinline struct module *load_module(void __user *umod, if (err < 0) goto unlink; add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); - if (mod->sect_attrs) - add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs); + add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs); /* Get rid of temporary copy */ vfree(hdr); -- cgit v1.2.3