From 5a0e3ad6af8660be21ca98a971cd00f331318c05 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Mar 2010 17:04:11 +0900 Subject: include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn --- lib/dynamic_debug.c | 1 + 1 file changed, 1 insertion(+) (limited to 'lib/dynamic_debug.c') diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index f9350291598..d6b8b9b1abf 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -25,6 +25,7 @@ #include #include #include +#include extern struct _ddebug __start___verbose[]; extern struct _ddebug __stop___verbose[]; -- cgit v1.2.3 From ea46c8f774f295c45fac48101d54be347d3d453b Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 24 May 2010 14:33:21 -0700 Subject: dynamic_debug: small cleanup in ddebug_proc_write() This doesn't change behavior at all. In the original code, if nwords was zero then ddebug_parse_query() would return -EINVAL, now we just do it earlier. Signed-off-by: Dan Carpenter Acked-by: Jason Baron Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/dynamic_debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/dynamic_debug.c') diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index d6b8b9b1abf..3df8eb17a60 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -456,7 +456,7 @@ static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, __func__, (int)len); nwords = ddebug_tokenize(tmpbuf, words, MAXWORDS); - if (nwords < 0) + if (nwords <= 0) return -EINVAL; if (ddebug_parse_query(words, nwords-1, &query)) return -EINVAL; -- cgit v1.2.3 From ff49d74ad383f54041378144ca1a229ee9aeaa59 Mon Sep 17 00:00:00 2001 From: Yehuda Sadeh Date: Sat, 3 Jul 2010 13:07:35 +1000 Subject: module: initialize module dynamic debug later We should initialize the module dynamic debug datastructures only after determining that the module is not loaded yet. This fixes a bug that introduced in 2.6.35-rc2, where when a trying to load a module twice, we also load it's dynamic printing data twice which causes all sorts of nasty issues. Also handle the dynamic debug cleanup later on failure. Signed-off-by: Yehuda Sadeh Signed-off-by: Rusty Russell (removed a #ifdef) Signed-off-by: Linus Torvalds --- include/linux/dynamic_debug.h | 4 ++-- kernel/module.c | 23 +++++++++++++++-------- lib/dynamic_debug.c | 2 +- 3 files changed, 18 insertions(+), 11 deletions(-) (limited to 'lib/dynamic_debug.c') diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index b3cd4de9432..52c0da4bdd1 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -40,7 +40,7 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n, const char *modname); #if defined(CONFIG_DYNAMIC_DEBUG) -extern int ddebug_remove_module(char *mod_name); +extern int ddebug_remove_module(const char *mod_name); #define __dynamic_dbg_enabled(dd) ({ \ int __ret = 0; \ @@ -73,7 +73,7 @@ extern int ddebug_remove_module(char *mod_name); #else -static inline int ddebug_remove_module(char *mod) +static inline int ddebug_remove_module(const char *mod) { return 0; } diff --git a/kernel/module.c b/kernel/module.c index 8c6b42840dd..5d2d28197c8 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2062,6 +2062,12 @@ static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num) #endif } +static void dynamic_debug_remove(struct _ddebug *debug) +{ + if (debug) + ddebug_remove_module(debug->modname); +} + static void *module_alloc_update_bounds(unsigned long size) { void *ret = module_alloc(size); @@ -2124,6 +2130,8 @@ static noinline struct module *load_module(void __user *umod, void *ptr = NULL; /* Stops spurious gcc warning */ unsigned long symoffs, stroffs, *strmap; void __percpu *percpu; + struct _ddebug *debug = NULL; + unsigned int num_debug = 0; mm_segment_t old_fs; @@ -2476,15 +2484,9 @@ static noinline struct module *load_module(void __user *umod, kfree(strmap); strmap = NULL; - if (!mod->taints) { - struct _ddebug *debug; - unsigned int num_debug; - + if (!mod->taints) debug = section_objs(hdr, sechdrs, secstrings, "__verbose", sizeof(*debug), &num_debug); - if (debug) - dynamic_debug_setup(debug, num_debug); - } err = module_finalize(hdr, sechdrs, mod); if (err < 0) @@ -2526,10 +2528,13 @@ static noinline struct module *load_module(void __user *umod, goto unlock; } + if (debug) + dynamic_debug_setup(debug, num_debug); + /* Find duplicate symbols */ err = verify_export_symbols(mod); if (err < 0) - goto unlock; + goto ddebug; list_add_rcu(&mod->list, &modules); mutex_unlock(&module_mutex); @@ -2557,6 +2562,8 @@ static noinline struct module *load_module(void __user *umod, mutex_lock(&module_mutex); /* Unlink carefully: kallsyms could be walking list. */ list_del_rcu(&mod->list); + ddebug: + dynamic_debug_remove(debug); unlock: mutex_unlock(&module_mutex); synchronize_sched(); diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 3df8eb17a60..02afc253372 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -692,7 +692,7 @@ static void ddebug_table_free(struct ddebug_table *dt) * Called in response to a module being unloaded. Removes * any ddebug_table's which point at the module. */ -int ddebug_remove_module(char *mod_name) +int ddebug_remove_module(const char *mod_name) { struct ddebug_table *dt, *nextdt; int ret = -ENOENT; -- cgit v1.2.3 From 52159d98be6f26c48f5e02c7ab3c9848a85979b5 Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Fri, 17 Sep 2010 11:09:17 -0400 Subject: jump label: Convert dynamic debug to use jump labels Convert the 'dynamic debug' infrastructure to use jump labels. Signed-off-by: Jason Baron LKML-Reference: Signed-off-by: Steven Rostedt --- include/linux/dynamic_debug.h | 39 ++++++++++++++------------ lib/dynamic_debug.c | 42 ++-------------------------- scripts/Makefile.lib | 11 +------- scripts/basic/Makefile | 2 +- scripts/basic/hash.c | 64 ------------------------------------------- 5 files changed, 26 insertions(+), 132 deletions(-) delete mode 100644 scripts/basic/hash.c (limited to 'lib/dynamic_debug.c') diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index 52c0da4bdd1..bef3cda44c4 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -1,6 +1,8 @@ #ifndef _DYNAMIC_DEBUG_H #define _DYNAMIC_DEBUG_H +#include + /* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They * use independent hash functions, to reduce the chance of false positives. @@ -22,8 +24,6 @@ struct _ddebug { const char *function; const char *filename; const char *format; - char primary_hash; - char secondary_hash; unsigned int lineno:24; /* * The flags field controls the behaviour at the callsite. @@ -33,6 +33,7 @@ struct _ddebug { #define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */ #define _DPRINTK_FLAGS_DEFAULT 0 unsigned int flags:8; + char enabled; } __attribute__((aligned(8))); @@ -42,33 +43,35 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n, #if defined(CONFIG_DYNAMIC_DEBUG) extern int ddebug_remove_module(const char *mod_name); -#define __dynamic_dbg_enabled(dd) ({ \ - int __ret = 0; \ - if (unlikely((dynamic_debug_enabled & (1LL << DEBUG_HASH)) && \ - (dynamic_debug_enabled2 & (1LL << DEBUG_HASH2)))) \ - if (unlikely(dd.flags)) \ - __ret = 1; \ - __ret; }) - #define dynamic_pr_debug(fmt, ...) do { \ + __label__ do_printk; \ + __label__ out; \ static struct _ddebug descriptor \ __used \ __attribute__((section("__verbose"), aligned(8))) = \ - { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ - DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ - if (__dynamic_dbg_enabled(descriptor)) \ - printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ + { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \ + _DPRINTK_FLAGS_DEFAULT }; \ + JUMP_LABEL(&descriptor.enabled, do_printk); \ + goto out; \ +do_printk: \ + printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ +out: ; \ } while (0) #define dynamic_dev_dbg(dev, fmt, ...) do { \ + __label__ do_printk; \ + __label__ out; \ static struct _ddebug descriptor \ __used \ __attribute__((section("__verbose"), aligned(8))) = \ - { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ - DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ - if (__dynamic_dbg_enabled(descriptor)) \ - dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \ + { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \ + _DPRINTK_FLAGS_DEFAULT }; \ + JUMP_LABEL(&descriptor.enabled, do_printk); \ + goto out; \ +do_printk: \ + dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \ +out: ; \ } while (0) #else diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 02afc253372..e925c7b960f 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -26,19 +26,11 @@ #include #include #include +#include extern struct _ddebug __start___verbose[]; extern struct _ddebug __stop___verbose[]; -/* dynamic_debug_enabled, and dynamic_debug_enabled2 are bitmasks in which - * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They - * use independent hash functions, to reduce the chance of false positives. - */ -long long dynamic_debug_enabled; -EXPORT_SYMBOL_GPL(dynamic_debug_enabled); -long long dynamic_debug_enabled2; -EXPORT_SYMBOL_GPL(dynamic_debug_enabled2); - struct ddebug_table { struct list_head link; char *mod_name; @@ -87,26 +79,6 @@ static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, return buf; } -/* - * must be called with ddebug_lock held - */ - -static int disabled_hash(char hash, bool first_table) -{ - struct ddebug_table *dt; - char table_hash_value; - - list_for_each_entry(dt, &ddebug_tables, link) { - if (first_table) - table_hash_value = dt->ddebugs->primary_hash; - else - table_hash_value = dt->ddebugs->secondary_hash; - if (dt->num_enabled && (hash == table_hash_value)) - return 0; - } - return 1; -} - /* * Search the tables for _ddebug's which match the given * `query' and apply the `flags' and `mask' to them. Tells @@ -170,17 +142,9 @@ static void ddebug_change(const struct ddebug_query *query, dt->num_enabled++; dp->flags = newflags; if (newflags) { - dynamic_debug_enabled |= - (1LL << dp->primary_hash); - dynamic_debug_enabled2 |= - (1LL << dp->secondary_hash); + enable_jump_label(&dp->enabled); } else { - if (disabled_hash(dp->primary_hash, true)) - dynamic_debug_enabled &= - ~(1LL << dp->primary_hash); - if (disabled_hash(dp->secondary_hash, false)) - dynamic_debug_enabled2 &= - ~(1LL << dp->secondary_hash); + disable_jump_label(&dp->enabled); } if (verbose) printk(KERN_INFO diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 54fd1b70013..7bfcf1a09ac 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -101,14 +101,6 @@ basename_flags = -D"KBUILD_BASENAME=KBUILD_STR($(call name-fix,$(basetarget)))" modname_flags = $(if $(filter 1,$(words $(modname))),\ -D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))") -#hash values -ifdef CONFIG_DYNAMIC_DEBUG -debug_flags = -D"DEBUG_HASH=$(shell ./scripts/basic/hash djb2 $(@D)$(modname))"\ - -D"DEBUG_HASH2=$(shell ./scripts/basic/hash r5 $(@D)$(modname))" -else -debug_flags = -endif - orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \ $(ccflags-y) $(CFLAGS_$(basetarget).o) _c_flags = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags)) @@ -152,8 +144,7 @@ endif c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ $(__c_flags) $(modkern_cflags) \ - -D"KBUILD_STR(s)=\#s" $(basename_flags) $(modname_flags) \ - $(debug_flags) + -D"KBUILD_STR(s)=\#s" $(basename_flags) $(modname_flags) a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ $(__a_flags) $(modkern_aflags) diff --git a/scripts/basic/Makefile b/scripts/basic/Makefile index 09559951df1..4c324a1f1e0 100644 --- a/scripts/basic/Makefile +++ b/scripts/basic/Makefile @@ -9,7 +9,7 @@ # fixdep: Used to generate dependency information during build process # docproc: Used in Documentation/DocBook -hostprogs-y := fixdep docproc hash +hostprogs-y := fixdep docproc always := $(hostprogs-y) # fixdep is needed to compile other host programs diff --git a/scripts/basic/hash.c b/scripts/basic/hash.c deleted file mode 100644 index 2ef5d3f666b..00000000000 --- a/scripts/basic/hash.c +++ /dev/null @@ -1,64 +0,0 @@ -/* - * Copyright (C) 2008 Red Hat, Inc., Jason Baron - * - */ - -#include -#include -#include - -#define DYNAMIC_DEBUG_HASH_BITS 6 - -static const char *program; - -static void usage(void) -{ - printf("Usage: %s \n", program); - exit(1); -} - -/* djb2 hashing algorithm by Dan Bernstein. From: - * http://www.cse.yorku.ca/~oz/hash.html - */ - -static unsigned int djb2_hash(char *str) -{ - unsigned long hash = 5381; - int c; - - c = *str; - while (c) { - hash = ((hash << 5) + hash) + c; - c = *++str; - } - return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1)); -} - -static unsigned int r5_hash(char *str) -{ - unsigned long hash = 0; - int c; - - c = *str; - while (c) { - hash = (hash + (c << 4) + (c >> 4)) * 11; - c = *++str; - } - return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1)); -} - -int main(int argc, char *argv[]) -{ - program = argv[0]; - - if (argc != 3) - usage(); - if (!strcmp(argv[1], "djb2")) - printf("%d\n", djb2_hash(argv[2])); - else if (!strcmp(argv[1], "r5")) - printf("%d\n", r5_hash(argv[2])); - else - usage(); - exit(0); -} - -- cgit v1.2.3 From 3b6e901f839f42afb40f614418df82c08b01320a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 14 Oct 2010 21:10:38 +0200 Subject: jump_label: Use more consistent naming Now that there's still only a few users around, rename things to make them more consistent. Signed-off-by: Peter Zijlstra LKML-Reference: <20101014203625.448565169@chello.nl> Signed-off-by: Ingo Molnar --- include/linux/jump_label.h | 8 ++++---- kernel/tracepoint.c | 6 +++--- lib/dynamic_debug.c | 4 ++-- 3 files changed, 9 insertions(+), 9 deletions(-) (limited to 'lib/dynamic_debug.c') diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index b72cd9f92c2..81be4962b7a 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -25,10 +25,10 @@ extern void jump_label_update(unsigned long key, enum jump_label_type type); extern void jump_label_apply_nops(struct module *mod); extern int jump_label_text_reserved(void *start, void *end); -#define enable_jump_label(key) \ +#define jump_label_enable(key) \ jump_label_update((unsigned long)key, JUMP_LABEL_ENABLE); -#define disable_jump_label(key) \ +#define jump_label_disable(key) \ jump_label_update((unsigned long)key, JUMP_LABEL_DISABLE); #else @@ -39,12 +39,12 @@ do { \ goto label; \ } while (0) -#define enable_jump_label(cond_var) \ +#define jump_label_enable(cond_var) \ do { \ *(cond_var) = 1; \ } while (0) -#define disable_jump_label(cond_var) \ +#define jump_label_disable(cond_var) \ do { \ *(cond_var) = 0; \ } while (0) diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index d6073a50a6c..e95ee7f31d4 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -265,10 +265,10 @@ static void set_tracepoint(struct tracepoint_entry **entry, */ rcu_assign_pointer(elem->funcs, (*entry)->funcs); if (!elem->state && active) { - enable_jump_label(&elem->state); + jump_label_enable(&elem->state); elem->state = active; } else if (elem->state && !active) { - disable_jump_label(&elem->state); + jump_label_disable(&elem->state); elem->state = active; } } @@ -285,7 +285,7 @@ static void disable_tracepoint(struct tracepoint *elem) elem->unregfunc(); if (elem->state) { - disable_jump_label(&elem->state); + jump_label_disable(&elem->state); elem->state = 0; } rcu_assign_pointer(elem->funcs, NULL); diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index e925c7b960f..7bd6df781ce 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -142,9 +142,9 @@ static void ddebug_change(const struct ddebug_query *query, dt->num_enabled++; dp->flags = newflags; if (newflags) { - enable_jump_label(&dp->enabled); + jump_label_enable(&dp->enabled); } else { - disable_jump_label(&dp->enabled); + jump_label_disable(&dp->enabled); } if (verbose) printk(KERN_INFO -- cgit v1.2.3 From fd89cfb8718753459fcea3fe6103d19de5e86c9b Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Fri, 6 Aug 2010 16:11:01 +0200 Subject: Dynamic Debug: Split out query string parsing/setup from proc_write The parsing and applying of dynamic debug strings is not only useful for /sys/../dynamic_debug/control write access, but can also be used for boot parameter parsing. The boot parameter is introduced in a follow up patch. Signed-off-by: Thomas Renninger Acked-by: jbaron@redhat.com Acked-by: Pekka Enberg Signed-off-by: Greg Kroah-Hartman --- lib/dynamic_debug.c | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-) (limited to 'lib/dynamic_debug.c') diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 02afc253372..84d103c474e 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -429,6 +429,27 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp, return 0; } +static int ddebug_exec_query(char *query_string) +{ + unsigned int flags = 0, mask = 0; + struct ddebug_query query; +#define MAXWORDS 9 + int nwords; + char *words[MAXWORDS]; + + nwords = ddebug_tokenize(query_string, words, MAXWORDS); + if (nwords <= 0) + return -EINVAL; + if (ddebug_parse_query(words, nwords-1, &query)) + return -EINVAL; + if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) + return -EINVAL; + + /* actually go and implement the change */ + ddebug_change(&query, flags, mask); + return 0; +} + /* * File_ops->write method for /dynamic_debug/conrol. Gathers the * command text from userspace, parses and executes it. @@ -436,12 +457,8 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp, static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, size_t len, loff_t *offp) { - unsigned int flags = 0, mask = 0; - struct ddebug_query query; -#define MAXWORDS 9 - int nwords; - char *words[MAXWORDS]; char tmpbuf[256]; + int ret; if (len == 0) return 0; @@ -455,16 +472,9 @@ static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, printk(KERN_INFO "%s: read %d bytes from userspace\n", __func__, (int)len); - nwords = ddebug_tokenize(tmpbuf, words, MAXWORDS); - if (nwords <= 0) - return -EINVAL; - if (ddebug_parse_query(words, nwords-1, &query)) - return -EINVAL; - if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) - return -EINVAL; - - /* actually go and implement the change */ - ddebug_change(&query, flags, mask); + ret = ddebug_exec_query(tmpbuf); + if (ret) + return ret; *offp += len; return len; -- cgit v1.2.3 From a648ec05bb950fae2f35d0490ddd6cf15010af72 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Fri, 6 Aug 2010 16:11:02 +0200 Subject: Dynamic Debug: Introduce ddebug_query= boot parameter Dynamic debug lacks the ability to enable debug messages at boot time. One could patch initramfs or service startup scripts to write to /sys/../dynamic_debug/control, but this sucks. This patch makes it possible to pass a query in the same format one can write to /sys/../dynamic_debug/control via boot param. When dynamic debug gets initialized, this query will automatically be applied. Signed-off-by: Thomas Renninger Acked-by: jbaron@redhat.com Acked-by: Pekka Enberg Signed-off-by: Greg Kroah-Hartman --- Documentation/dynamic-debug-howto.txt | 22 +++++++++++++++++++++- Documentation/kernel-parameters.txt | 7 ++++++- lib/dynamic_debug.c | 25 +++++++++++++++++++++++++ 3 files changed, 52 insertions(+), 2 deletions(-) (limited to 'lib/dynamic_debug.c') diff --git a/Documentation/dynamic-debug-howto.txt b/Documentation/dynamic-debug-howto.txt index 674c5663d34..58ea64a9616 100644 --- a/Documentation/dynamic-debug-howto.txt +++ b/Documentation/dynamic-debug-howto.txt @@ -24,7 +24,7 @@ Dynamic debug has even more useful features: read to display the complete list of known debug statements, to help guide you Controlling dynamic debug Behaviour -=============================== +=================================== The behaviour of pr_debug()/dev_debug()s are controlled via writing to a control file in the 'debugfs' filesystem. Thus, you must first mount the debugfs @@ -212,6 +212,26 @@ Note the regexp ^[-+=][scp]+$ matches a flags specification. Note also that there is no convenient syntax to remove all the flags at once, you need to use "-psc". + +Debug messages during boot process +================================== + +To be able to activate debug messages during the boot process, +even before userspace and debugfs exists, use the boot parameter: +ddebug_query="QUERY" + +QUERY follows the syntax described above, but must not exceed 1023 +characters. The enablement of debug messages is done as an arch_initcall. +Thus you can enable debug messages in all code processed after this +arch_initcall via this boot parameter. +On an x86 system for example ACPI enablement is a subsys_initcall and +ddebug_query="file ec.c +p" +will show early Embedded Controller transactions during ACPI setup if +your machine (typically a laptop) has an Embedded Controller. +PCI (or other devices) initialization also is a hot candidate for using +this boot parameter for debugging purposes. + + Examples ======== diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 8dd7248508a..3d854c9ae53 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -43,10 +43,11 @@ parameter is applicable: AVR32 AVR32 architecture is enabled. AX25 Appropriate AX.25 support is enabled. BLACKFIN Blackfin architecture is enabled. - DRM Direct Rendering Management support is enabled. EDD BIOS Enhanced Disk Drive Services (EDD) is enabled EFI EFI Partitioning (GPT) is enabled EIDE EIDE/ATAPI support is enabled. + DRM Direct Rendering Management support is enabled. + DYNAMIC_DEBUG Build in debug messages and enable them at runtime FB The frame buffer device is enabled. GCOV GCOV profiling is enabled. HW Appropriate hardware is enabled. @@ -570,6 +571,10 @@ and is between 256 and 4096 characters. It is defined in the file Format: , See also Documentation/input/joystick-parport.txt + ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot + time. See Documentation/dynamic-debug-howto.txt for + details. + debug [KNL] Enable kernel debugging (events log level). debug_locks_verbose= diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 84d103c474e..44ce66bdb21 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -450,6 +450,19 @@ static int ddebug_exec_query(char *query_string) return 0; } +static __initdata char ddebug_setup_string[1024]; +static __init int ddebug_setup_query(char *str) +{ + if (strlen(str) >= 1024) { + pr_warning("ddebug boot param string too large\n"); + return 0; + } + strcpy(ddebug_setup_string, str); + return 1; +} + +__setup("ddebug_query=", ddebug_setup_query); + /* * File_ops->write method for /dynamic_debug/conrol. Gathers the * command text from userspace, parses and executes it. @@ -769,6 +782,18 @@ static int __init dynamic_debug_init(void) } ret = ddebug_add_module(iter_start, n, modname); } + + /* ddebug_query boot param got passed -> set it up */ + if (ddebug_setup_string[0] != '\0') { + ret = ddebug_exec_query(ddebug_setup_string); + if (ret) + pr_warning("Invalid ddebug boot param %s", + ddebug_setup_string); + else + pr_info("ddebug initialized with string %s", + ddebug_setup_string); + } + out_free: if (ret) { ddebug_remove_all_tables(); -- cgit v1.2.3 From 6a5c083de2f5fbf89a4b0a251be2c2205434d7ea Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Fri, 6 Aug 2010 16:11:03 +0200 Subject: Dynamic Debug: Initialize dynamic debug earlier via arch_initcall Having the ddebug_query= boot parameter it makes sense to set up dynamic debug as soon as possible. I expect sysfs files cannot be set up via an arch_initcall, because this one is even before fs_initcall. Therefore I splitted the dynamic_debug_init function into an early one and a later one providing /sys/../dynamic_debug/control file. Possibly dynamic_debug can be initialized even earlier, not sure whether this still makes sense then. I picked up arch_initcall as it covers quite a lot already. Dynamic debug needs to allocate memory, therefore it's not easily possible to set it up even before the command line gets parsed. Therefore the boot param query string is stored in a temp string which is applied when dynamic debug gets set up. This has been tested with ddebug_query="file ec.c +p" and I could retrieve pr_debug() messages early at boot during ACPI setup: ACPI: EC: Look up EC in DSDT ACPI: EC: ---> status = 0x08 ACPI: EC: transaction start ACPI: EC: <--- command = 0x80 ACPI: EC: ~~~> interrupt ACPI: EC: ---> status = 0x08 ACPI: EC: <--- data = 0xa4 ... ACPI: Interpreter enabled ACPI: (supports S0 S3 S4 S5) ACPI: Using IOAPIC for interrupt routing ACPI: EC: ---> status = 0x00 ACPI: EC: transaction start ACPI: EC: <--- command = 0x80 Signed-off-by: Thomas Renninger Acked-by: jbaron@redhat.com Acked-by: Pekka Enberg CC: linux-acpi@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- lib/dynamic_debug.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) (limited to 'lib/dynamic_debug.c') diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 44ce66bdb21..a687d902daa 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -748,13 +748,14 @@ static void ddebug_remove_all_tables(void) mutex_unlock(&ddebug_lock); } -static int __init dynamic_debug_init(void) +static __initdata int ddebug_init_success; + +static int __init dynamic_debug_init_debugfs(void) { struct dentry *dir, *file; - struct _ddebug *iter, *iter_start; - const char *modname = NULL; - int ret = 0; - int n = 0; + + if (!ddebug_init_success) + return -ENODEV; dir = debugfs_create_dir("dynamic_debug", NULL); if (!dir) @@ -765,6 +766,16 @@ static int __init dynamic_debug_init(void) debugfs_remove(dir); return -ENOMEM; } + return 0; +} + +static int __init dynamic_debug_init(void) +{ + struct _ddebug *iter, *iter_start; + const char *modname = NULL; + int ret = 0; + int n = 0; + if (__start___verbose != __stop___verbose) { iter = __start___verbose; modname = iter->modname; @@ -795,11 +806,13 @@ static int __init dynamic_debug_init(void) } out_free: - if (ret) { + if (ret) ddebug_remove_all_tables(); - debugfs_remove(dir); - debugfs_remove(file); - } + else + ddebug_init_success = 1; return 0; } -module_init(dynamic_debug_init); +/* Allow early initialization for boot messages via boot param */ +arch_initcall(dynamic_debug_init); +/* Debugfs setup must be done later */ +module_init(dynamic_debug_init_debugfs); -- cgit v1.2.3 From 2d75af2f2a7a6103a6d539a492fe81deacabde44 Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Fri, 7 Jan 2011 13:36:58 -0500 Subject: dynamic debug: Fix build issue with older gcc On older gcc (3.3) dynamic debug fails to compile: include/net/inet_connection_sock.h: In function `inet_csk_reset_xmit_timer': include/net/inet_connection_sock.h:236: error: duplicate label declaration `do_printk' include/net/inet_connection_sock.h:219: error: this is a previous declaration include/net/inet_connection_sock.h:236: error: duplicate label declaration `out' include/net/inet_connection_sock.h:219: error: this is a previous declaration include/net/inet_connection_sock.h:236: error: duplicate label `do_printk' include/net/inet_connection_sock.h:236: error: duplicate label `out' Fix, by reverting the usage of JUMP_LABEL() in dynamic debug for now. Cc: Reported-by: Tetsuo Handa Tested-by: Tetsuo Handa Signed-off-by: Jason Baron Signed-off-by: Steven Rostedt --- include/linux/dynamic_debug.h | 18 ++++-------------- lib/dynamic_debug.c | 9 ++++----- 2 files changed, 8 insertions(+), 19 deletions(-) (limited to 'lib/dynamic_debug.c') diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index a90b3892074..1c70028f81f 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -44,34 +44,24 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n, extern int ddebug_remove_module(const char *mod_name); #define dynamic_pr_debug(fmt, ...) do { \ - __label__ do_printk; \ - __label__ out; \ static struct _ddebug descriptor \ __used \ __attribute__((section("__verbose"), aligned(8))) = \ { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \ _DPRINTK_FLAGS_DEFAULT }; \ - JUMP_LABEL(&descriptor.enabled, do_printk); \ - goto out; \ -do_printk: \ - printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ -out: ; \ + if (unlikely(descriptor.enabled)) \ + printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ } while (0) #define dynamic_dev_dbg(dev, fmt, ...) do { \ - __label__ do_printk; \ - __label__ out; \ static struct _ddebug descriptor \ __used \ __attribute__((section("__verbose"), aligned(8))) = \ { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \ _DPRINTK_FLAGS_DEFAULT }; \ - JUMP_LABEL(&descriptor.enabled, do_printk); \ - goto out; \ -do_printk: \ - dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \ -out: ; \ + if (unlikely(descriptor.enabled)) \ + dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \ } while (0) #else diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 3094318bfea..b335acb43be 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -141,11 +141,10 @@ static void ddebug_change(const struct ddebug_query *query, else if (!dp->flags) dt->num_enabled++; dp->flags = newflags; - if (newflags) { - jump_label_enable(&dp->enabled); - } else { - jump_label_disable(&dp->enabled); - } + if (newflags) + dp->enabled = 1; + else + dp->enabled = 0; if (verbose) printk(KERN_INFO "ddebug: changed %s:%d [%s]%s %s\n", -- cgit v1.2.3