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Message-Id: <200810221005.59874.rusty@rustcorp.com.au>
Date: Wed, 22 Oct 2008 10:05:58 +1100
From: Rusty Russell <rusty@...tcorp.com.au>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...e.hu>,
Andi Kleen <ak@...e.de>,
Heiko Carstens <heiko.carstens@...ibm.com>,
"Greg Kroah-Hartman" <gregkh@...e.de>,
Arjan van de Ven <arjan@...radead.org>
Subject: [PULL] module, param and stop_machine patches
The following changes since commit 2515ddc6db8eb49a79f0fe5e67ff09ac7c81eab4:
Paul Mundt (1):
binfmt_elf_fdpic: Update for cputime changes.
are available in the git repository at:
ssh://master.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus.git master
Andi Kleen (1):
Remove stop_machine during module load v2
Heiko Carstens (4):
Call init_workqueues before pre smp initcalls.
workqueue: introduce create_rt_workqueue
stop_machine: use workqueues instead of kernel threads
stop_machine: fix error code handling on multiple cpus
Rusty Russell (6):
module: simplify load_module.
module: check kernel param length at compile time, not runtime
param: Fix duplicate module prefixes
core_param() for genuinely core kernel parameters
Make initcall_debug a core_param
Make panic= and panic_on_oops into core_params
include/linux/module.h | 6 +-
include/linux/moduleparam.h | 25 ++++-
include/linux/workqueue.h | 18 ++--
init/main.c | 12 +--
kernel/module.c | 284 ++++++++++++++++++------------------------
kernel/panic.c | 17 +--
kernel/params.c | 274 ++++++++++++++++++++++-------------------
kernel/stop_machine.c | 120 +++++++-----------
kernel/workqueue.c | 7 +-
9 files changed, 364 insertions(+), 399 deletions(-)
diff --git a/include/linux/module.h b/include/linux/module.h
index 5d2970c..3bfed01 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -29,7 +29,7 @@
#define MODULE_SYMBOL_PREFIX ""
#endif
-#define MODULE_NAME_LEN (64 - sizeof(unsigned long))
+#define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
struct kernel_symbol
{
@@ -60,6 +60,7 @@ struct module_kobject
struct kobject kobj;
struct module *mod;
struct kobject *drivers_dir;
+ struct module_param_attrs *mp;
};
/* These are either module local, or the kernel's dummy ones. */
@@ -242,7 +243,6 @@ struct module
/* Sysfs stuff. */
struct module_kobject mkobj;
- struct module_param_attrs *param_attrs;
struct module_attribute *modinfo_attrs;
const char *version;
const char *srcversion;
@@ -277,7 +277,7 @@ struct module
/* Exception table */
unsigned int num_exentries;
- const struct exception_table_entry *extable;
+ struct exception_table_entry *extable;
/* Startup function. */
int (*init)(void);
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index ec62438..e4af339 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -13,6 +13,9 @@
#define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
#endif
+/* Chosen so that structs with an unsigned long line up. */
+#define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
+
#ifdef MODULE
#define ___module_cat(a,b) __mod_ ## a ## b
#define __module_cat(a,b) ___module_cat(a,b)
@@ -79,7 +82,8 @@ struct kparam_array
#define __module_param_call(prefix, name, set, get, arg, perm) \
/* Default value instead of permissions? */ \
static int __param_perm_check_##name __attribute__((unused)) = \
- BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)); \
+ BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \
+ + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \
static const char __param_str_##name[] = prefix #name; \
static struct kernel_param __moduleparam_const __param_##name \
__used \
@@ -100,6 +104,25 @@ struct kparam_array
#define module_param(name, type, perm) \
module_param_named(name, name, type, perm)
+#ifndef MODULE
+/**
+ * core_param - define a historical core kernel parameter.
+ * @name: the name of the cmdline and sysfs parameter (often the same as var)
+ * @var: the variable
+ * @type: the type (for param_set_##type and param_get_##type)
+ * @perm: visibility in sysfs
+ *
+ * core_param is just like module_param(), but cannot be modular and
+ * doesn't add a prefix (such as "printk."). This is for compatibility
+ * with __setup(), and it makes sense as truly core parameters aren't
+ * tied to the particular file they're in.
+ */
+#define core_param(name, var, type, perm) \
+ param_check_##type(name, &(var)); \
+ __module_param_call("", name, param_set_##type, param_get_##type, \
+ &var, perm)
+#endif /* !MODULE */
+
/* Actually copy string: maxlen param is usually sizeof(string). */
#define module_param_string(name, string, len, perm) \
static const struct kparam_string __param_string_##name \
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 5c158c4..89a5a12 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -149,11 +149,11 @@ struct execute_work {
extern struct workqueue_struct *
__create_workqueue_key(const char *name, int singlethread,
- int freezeable, struct lock_class_key *key,
+ int freezeable, int rt, struct lock_class_key *key,
const char *lock_name);
#ifdef CONFIG_LOCKDEP
-#define __create_workqueue(name, singlethread, freezeable) \
+#define __create_workqueue(name, singlethread, freezeable, rt) \
({ \
static struct lock_class_key __key; \
const char *__lock_name; \
@@ -164,17 +164,19 @@ __create_workqueue_key(const char *name, int singlethread,
__lock_name = #name; \
\
__create_workqueue_key((name), (singlethread), \
- (freezeable), &__key, \
+ (freezeable), (rt), &__key, \
__lock_name); \
})
#else
-#define __create_workqueue(name, singlethread, freezeable) \
- __create_workqueue_key((name), (singlethread), (freezeable), NULL, NULL)
+#define __create_workqueue(name, singlethread, freezeable, rt) \
+ __create_workqueue_key((name), (singlethread), (freezeable), (rt), \
+ NULL, NULL)
#endif
-#define create_workqueue(name) __create_workqueue((name), 0, 0)
-#define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1)
-#define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0)
+#define create_workqueue(name) __create_workqueue((name), 0, 0, 0)
+#define create_rt_workqueue(name) __create_workqueue((name), 0, 0, 1)
+#define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1, 0)
+#define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0, 0)
extern void destroy_workqueue(struct workqueue_struct *wq);
diff --git a/init/main.c b/init/main.c
index 3e17a3b..6c7fd13 100644
--- a/init/main.c
+++ b/init/main.c
@@ -697,13 +697,7 @@ asmlinkage void __init start_kernel(void)
}
static int initcall_debug;
-
-static int __init initcall_debug_setup(char *str)
-{
- initcall_debug = 1;
- return 1;
-}
-__setup("initcall_debug", initcall_debug_setup);
+core_param(initcall_debug, initcall_debug, bool, 0644);
int do_one_initcall(initcall_t fn)
{
@@ -773,8 +767,6 @@ static void __init do_initcalls(void)
static void __init do_basic_setup(void)
{
rcu_init_sched(); /* needed by module_init stage. */
- /* drivers will send hotplug events */
- init_workqueues();
usermodehelper_init();
driver_init();
init_irq_proc();
@@ -858,6 +850,8 @@ static int __init kernel_init(void * unused)
cad_pid = task_pid(current);
+ init_workqueues();
+
smp_prepare_cpus(setup_max_cpus);
do_pre_smp_initcalls();
diff --git a/kernel/module.c b/kernel/module.c
index 0d8d21e..c0f1826 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -42,6 +42,7 @@
#include <linux/string.h>
#include <linux/mutex.h>
#include <linux/unwind.h>
+#include <linux/rculist.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <linux/license.h>
@@ -63,7 +64,7 @@
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
/* List of modules, protected by module_mutex or preempt_disable
- * (add/delete uses stop_machine). */
+ * (delete uses stop_machine/add uses RCU list operations). */
static DEFINE_MUTEX(module_mutex);
static LIST_HEAD(modules);
@@ -132,6 +133,29 @@ static unsigned int find_sec(Elf_Ehdr *hdr,
return 0;
}
+/* Find a module section, or NULL. */
+static void *section_addr(Elf_Ehdr *hdr, Elf_Shdr *shdrs,
+ const char *secstrings, const char *name)
+{
+ /* Section 0 has sh_addr 0. */
+ return (void *)shdrs[find_sec(hdr, shdrs, secstrings, name)].sh_addr;
+}
+
+/* Find a module section, or NULL. Fill in number of "objects" in section. */
+static void *section_objs(Elf_Ehdr *hdr,
+ Elf_Shdr *sechdrs,
+ const char *secstrings,
+ const char *name,
+ size_t object_size,
+ unsigned int *num)
+{
+ unsigned int sec = find_sec(hdr, sechdrs, secstrings, name);
+
+ /* Section 0 has sh_addr 0 and sh_size 0. */
+ *num = sechdrs[sec].sh_size / object_size;
+ return (void *)sechdrs[sec].sh_addr;
+}
+
/* Provided by the linker */
extern const struct kernel_symbol __start___ksymtab[];
extern const struct kernel_symbol __stop___ksymtab[];
@@ -218,7 +242,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr,
if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
return true;
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
struct symsearch arr[] = {
{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
NOT_GPL_ONLY, false },
@@ -1394,17 +1418,6 @@ static void mod_kobject_remove(struct module *mod)
}
/*
- * link the module with the whole machine is stopped with interrupts off
- * - this defends against kallsyms not taking locks
- */
-static int __link_module(void *_mod)
-{
- struct module *mod = _mod;
- list_add(&mod->list, &modules);
- return 0;
-}
-
-/*
* unlink the module with the whole machine is stopped with interrupts off
* - this defends against kallsyms not taking locks
*/
@@ -1789,32 +1802,20 @@ static inline void add_kallsyms(struct module *mod,
}
#endif /* CONFIG_KALLSYMS */
-#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG
-static void dynamic_printk_setup(Elf_Shdr *sechdrs, unsigned int verboseindex)
+static void dynamic_printk_setup(struct mod_debug *debug, unsigned int num)
{
- struct mod_debug *debug_info;
- unsigned long pos, end;
- unsigned int num_verbose;
-
- pos = sechdrs[verboseindex].sh_addr;
- num_verbose = sechdrs[verboseindex].sh_size /
- sizeof(struct mod_debug);
- end = pos + (num_verbose * sizeof(struct mod_debug));
+#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG
+ unsigned int i;
- for (; pos < end; pos += sizeof(struct mod_debug)) {
- debug_info = (struct mod_debug *)pos;
- register_dynamic_debug_module(debug_info->modname,
- debug_info->type, debug_info->logical_modname,
- debug_info->flag_names, debug_info->hash,
- debug_info->hash2);
+ for (i = 0; i < num; i++) {
+ register_dynamic_debug_module(debug[i].modname,
+ debug[i].type,
+ debug[i].logical_modname,
+ debug[i].flag_names,
+ debug[i].hash, debug[i].hash2);
}
-}
-#else
-static inline void dynamic_printk_setup(Elf_Shdr *sechdrs,
- unsigned int verboseindex)
-{
-}
#endif /* CONFIG_DYNAMIC_PRINTK_DEBUG */
+}
static void *module_alloc_update_bounds(unsigned long size)
{
@@ -1843,37 +1844,14 @@ static noinline struct module *load_module(void __user *umod,
unsigned int i;
unsigned int symindex = 0;
unsigned int strindex = 0;
- unsigned int setupindex;
- unsigned int exindex;
- unsigned int exportindex;
- unsigned int modindex;
- unsigned int obsparmindex;
- unsigned int infoindex;
- unsigned int gplindex;
- unsigned int crcindex;
- unsigned int gplcrcindex;
- unsigned int versindex;
- unsigned int pcpuindex;
- unsigned int gplfutureindex;
- unsigned int gplfuturecrcindex;
+ unsigned int modindex, versindex, infoindex, pcpuindex;
unsigned int unwindex = 0;
-#ifdef CONFIG_UNUSED_SYMBOLS
- unsigned int unusedindex;
- unsigned int unusedcrcindex;
- unsigned int unusedgplindex;
- unsigned int unusedgplcrcindex;
-#endif
- unsigned int markersindex;
- unsigned int markersstringsindex;
- unsigned int verboseindex;
- unsigned int tracepointsindex;
- unsigned int tracepointsstringsindex;
- unsigned int mcountindex;
+ unsigned int num_kp, num_mcount;
+ struct kernel_param *kp;
struct module *mod;
long err = 0;
void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
- void *mseg;
- struct exception_table_entry *extable;
+ unsigned long *mseg;
mm_segment_t old_fs;
DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
@@ -1937,6 +1915,7 @@ static noinline struct module *load_module(void __user *umod,
err = -ENOEXEC;
goto free_hdr;
}
+ /* This is temporary: point mod into copy of data. */
mod = (void *)sechdrs[modindex].sh_addr;
if (symindex == 0) {
@@ -1946,22 +1925,6 @@ static noinline struct module *load_module(void __user *umod,
goto free_hdr;
}
- /* Optional sections */
- exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
- gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
- gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
- crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
- gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
- gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
-#ifdef CONFIG_UNUSED_SYMBOLS
- unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
- unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
- unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
- unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
-#endif
- setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
- exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
- obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
@@ -2117,42 +2080,57 @@ static noinline struct module *load_module(void __user *umod,
if (err < 0)
goto cleanup;
- /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
- mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
- mod->syms = (void *)sechdrs[exportindex].sh_addr;
- if (crcindex)
- mod->crcs = (void *)sechdrs[crcindex].sh_addr;
- mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
- mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
- if (gplcrcindex)
- mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
- mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
- sizeof(*mod->gpl_future_syms);
- mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
- if (gplfuturecrcindex)
- mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
+ /* Now we've got everything in the final locations, we can
+ * find optional sections. */
+ kp = section_objs(hdr, sechdrs, secstrings, "__param", sizeof(*kp),
+ &num_kp);
+ mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab",
+ sizeof(*mod->syms), &mod->num_syms);
+ mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab");
+ mod->gpl_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_gpl",
+ sizeof(*mod->gpl_syms),
+ &mod->num_gpl_syms);
+ mod->gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_gpl");
+ mod->gpl_future_syms = section_objs(hdr, sechdrs, secstrings,
+ "__ksymtab_gpl_future",
+ sizeof(*mod->gpl_future_syms),
+ &mod->num_gpl_future_syms);
+ mod->gpl_future_crcs = section_addr(hdr, sechdrs, secstrings,
+ "__kcrctab_gpl_future");
#ifdef CONFIG_UNUSED_SYMBOLS
- mod->num_unused_syms = sechdrs[unusedindex].sh_size /
- sizeof(*mod->unused_syms);
- mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
- sizeof(*mod->unused_gpl_syms);
- mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
- if (unusedcrcindex)
- mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
- mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
- if (unusedgplcrcindex)
- mod->unused_gpl_crcs
- = (void *)sechdrs[unusedgplcrcindex].sh_addr;
+ mod->unused_syms = section_objs(hdr, sechdrs, secstrings,
+ "__ksymtab_unused",
+ sizeof(*mod->unused_syms),
+ &mod->num_unused_syms);
+ mod->unused_crcs = section_addr(hdr, sechdrs, secstrings,
+ "__kcrctab_unused");
+ mod->unused_gpl_syms = section_objs(hdr, sechdrs, secstrings,
+ "__ksymtab_unused_gpl",
+ sizeof(*mod->unused_gpl_syms),
+ &mod->num_unused_gpl_syms);
+ mod->unused_gpl_crcs = section_addr(hdr, sechdrs, secstrings,
+ "__kcrctab_unused_gpl");
+#endif
+
+#ifdef CONFIG_MARKERS
+ mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers",
+ sizeof(*mod->markers), &mod->num_markers);
+#endif
+#ifdef CONFIG_TRACEPOINTS
+ mod->tracepoints = section_objs(hdr, sechdrs, secstrings,
+ "__tracepoints",
+ sizeof(*mod->tracepoints),
+ &mod->num_tracepoints);
#endif
#ifdef CONFIG_MODVERSIONS
- if ((mod->num_syms && !crcindex)
- || (mod->num_gpl_syms && !gplcrcindex)
- || (mod->num_gpl_future_syms && !gplfuturecrcindex)
+ if ((mod->num_syms && !mod->crcs)
+ || (mod->num_gpl_syms && !mod->gpl_crcs)
+ || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
#ifdef CONFIG_UNUSED_SYMBOLS
- || (mod->num_unused_syms && !unusedcrcindex)
- || (mod->num_unused_gpl_syms && !unusedgplcrcindex)
+ || (mod->num_unused_syms && !mod->unused_crcs)
+ || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
#endif
) {
printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name);
@@ -2161,16 +2139,6 @@ static noinline struct module *load_module(void __user *umod,
goto cleanup;
}
#endif
- markersindex = find_sec(hdr, sechdrs, secstrings, "__markers");
- markersstringsindex = find_sec(hdr, sechdrs, secstrings,
- "__markers_strings");
- verboseindex = find_sec(hdr, sechdrs, secstrings, "__verbose");
- tracepointsindex = find_sec(hdr, sechdrs, secstrings, "__tracepoints");
- tracepointsstringsindex = find_sec(hdr, sechdrs, secstrings,
- "__tracepoints_strings");
-
- mcountindex = find_sec(hdr, sechdrs, secstrings,
- "__mcount_loc");
/* Now do relocations. */
for (i = 1; i < hdr->e_shnum; i++) {
@@ -2193,28 +2161,16 @@ static noinline struct module *load_module(void __user *umod,
if (err < 0)
goto cleanup;
}
-#ifdef CONFIG_MARKERS
- mod->markers = (void *)sechdrs[markersindex].sh_addr;
- mod->num_markers =
- sechdrs[markersindex].sh_size / sizeof(*mod->markers);
-#endif
-#ifdef CONFIG_TRACEPOINTS
- mod->tracepoints = (void *)sechdrs[tracepointsindex].sh_addr;
- mod->num_tracepoints =
- sechdrs[tracepointsindex].sh_size / sizeof(*mod->tracepoints);
-#endif
-
/* Find duplicate symbols */
err = verify_export_symbols(mod);
-
if (err < 0)
goto cleanup;
/* Set up and sort exception table */
- mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
- mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
- sort_extable(extable, extable + mod->num_exentries);
+ mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
+ sizeof(*mod->extable), &mod->num_exentries);
+ sort_extable(mod->extable, mod->extable + mod->num_exentries);
/* Finally, copy percpu area over. */
percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
@@ -2223,11 +2179,17 @@ static noinline struct module *load_module(void __user *umod,
add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
if (!mod->taints) {
+ struct mod_debug *debug;
+ unsigned int num_debug;
+
#ifdef CONFIG_MARKERS
marker_update_probe_range(mod->markers,
mod->markers + mod->num_markers);
#endif
- dynamic_printk_setup(sechdrs, verboseindex);
+ debug = section_objs(hdr, sechdrs, secstrings, "__verbose",
+ sizeof(*debug), &num_debug);
+ dynamic_printk_setup(debug, num_debug);
+
#ifdef CONFIG_TRACEPOINTS
tracepoint_update_probe_range(mod->tracepoints,
mod->tracepoints + mod->num_tracepoints);
@@ -2235,8 +2197,9 @@ static noinline struct module *load_module(void __user *umod,
}
/* sechdrs[0].sh_size is always zero */
- mseg = (void *)sechdrs[mcountindex].sh_addr;
- ftrace_init_module(mseg, mseg + sechdrs[mcountindex].sh_size);
+ mseg = section_objs(hdr, sechdrs, secstrings, "__mcount_loc",
+ sizeof(*mseg), &num_mcount);
+ ftrace_init_module(mseg, mseg + num_mcount);
err = module_finalize(hdr, sechdrs, mod);
if (err < 0)
@@ -2261,30 +2224,24 @@ static noinline struct module *load_module(void __user *umod,
set_fs(old_fs);
mod->args = args;
- if (obsparmindex)
+ if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
mod->name);
/* Now sew it into the lists so we can get lockdep and oops
- * info during argument parsing. Noone should access us, since
- * strong_try_module_get() will fail. */
- stop_machine(__link_module, mod, NULL);
-
- /* Size of section 0 is 0, so this works well if no params */
- err = parse_args(mod->name, mod->args,
- (struct kernel_param *)
- sechdrs[setupindex].sh_addr,
- sechdrs[setupindex].sh_size
- / sizeof(struct kernel_param),
- NULL);
+ * info during argument parsing. Noone should access us, since
+ * strong_try_module_get() will fail.
+ * lockdep/oops can run asynchronous, so use the RCU list insertion
+ * function to insert in a way safe to concurrent readers.
+ * The mutex protects against concurrent writers.
+ */
+ list_add_rcu(&mod->list, &modules);
+
+ err = parse_args(mod->name, mod->args, kp, num_kp, NULL);
if (err < 0)
goto unlink;
- err = mod_sysfs_setup(mod,
- (struct kernel_param *)
- sechdrs[setupindex].sh_addr,
- sechdrs[setupindex].sh_size
- / sizeof(struct kernel_param));
+ err = mod_sysfs_setup(mod, kp, num_kp);
if (err < 0)
goto unlink;
add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
@@ -2473,7 +2430,7 @@ const char *module_address_lookup(unsigned long addr,
const char *ret = NULL;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size)
|| within(addr, mod->module_core, mod->core_size)) {
if (modname)
@@ -2496,7 +2453,7 @@ int lookup_module_symbol_name(unsigned long addr, char *symname)
struct module *mod;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size) ||
within(addr, mod->module_core, mod->core_size)) {
const char *sym;
@@ -2520,7 +2477,7 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
struct module *mod;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size) ||
within(addr, mod->module_core, mod->core_size)) {
const char *sym;
@@ -2547,7 +2504,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
struct module *mod;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (symnum < mod->num_symtab) {
*value = mod->symtab[symnum].st_value;
*type = mod->symtab[symnum].st_info;
@@ -2590,7 +2547,7 @@ unsigned long module_kallsyms_lookup_name(const char *name)
ret = mod_find_symname(mod, colon+1);
*colon = ':';
} else {
- list_for_each_entry(mod, &modules, list)
+ list_for_each_entry_rcu(mod, &modules, list)
if ((ret = mod_find_symname(mod, name)) != 0)
break;
}
@@ -2693,7 +2650,7 @@ const struct exception_table_entry *search_module_extables(unsigned long addr)
struct module *mod;
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (mod->num_exentries == 0)
continue;
@@ -2719,7 +2676,7 @@ int is_module_address(unsigned long addr)
preempt_disable();
- list_for_each_entry(mod, &modules, list) {
+ list_for_each_entry_rcu(mod, &modules, list) {
if (within(addr, mod->module_core, mod->core_size)) {
preempt_enable();
return 1;
@@ -2740,7 +2697,7 @@ struct module *__module_text_address(unsigned long addr)
if (addr < module_addr_min || addr > module_addr_max)
return NULL;
- list_for_each_entry(mod, &modules, list)
+ list_for_each_entry_rcu(mod, &modules, list)
if (within(addr, mod->module_init, mod->init_text_size)
|| within(addr, mod->module_core, mod->core_text_size))
return mod;
@@ -2765,8 +2722,11 @@ void print_modules(void)
char buf[8];
printk("Modules linked in:");
- list_for_each_entry(mod, &modules, list)
+ /* Most callers should already have preempt disabled, but make sure */
+ preempt_disable();
+ list_for_each_entry_rcu(mod, &modules, list)
printk(" %s%s", mod->name, module_flags(mod, buf));
+ preempt_enable();
if (last_unloaded_module[0])
printk(" [last unloaded: %s]", last_unloaded_module);
printk("\n");
diff --git a/kernel/panic.c b/kernel/panic.c
index bda561e..6513aac 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -34,13 +34,6 @@ ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
EXPORT_SYMBOL(panic_notifier_list);
-static int __init panic_setup(char *str)
-{
- panic_timeout = simple_strtoul(str, NULL, 0);
- return 1;
-}
-__setup("panic=", panic_setup);
-
static long no_blink(long time)
{
return 0;
@@ -218,13 +211,6 @@ void add_taint(unsigned flag)
}
EXPORT_SYMBOL(add_taint);
-static int __init pause_on_oops_setup(char *str)
-{
- pause_on_oops = simple_strtoul(str, NULL, 0);
- return 1;
-}
-__setup("pause_on_oops=", pause_on_oops_setup);
-
static void spin_msec(int msecs)
{
int i;
@@ -384,3 +370,6 @@ void __stack_chk_fail(void)
}
EXPORT_SYMBOL(__stack_chk_fail);
#endif
+
+core_param(panic, panic_timeout, int, 0644);
+core_param(pause_on_oops, pause_on_oops, int, 0644);
diff --git a/kernel/params.c b/kernel/params.c
index afc46a2..b077f1b 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -373,6 +373,8 @@ int param_get_string(char *buffer, struct kernel_param *kp)
}
/* sysfs output in /sys/modules/XYZ/parameters/ */
+#define to_module_attr(n) container_of(n, struct module_attribute, attr);
+#define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
extern struct kernel_param __start___param[], __stop___param[];
@@ -384,6 +386,7 @@ struct param_attribute
struct module_param_attrs
{
+ unsigned int num;
struct attribute_group grp;
struct param_attribute attrs[0];
};
@@ -434,69 +437,84 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
#ifdef CONFIG_SYSFS
/*
- * param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME
- * @mk: struct module_kobject (contains parent kobject)
- * @kparam: array of struct kernel_param, the actual parameter definitions
- * @num_params: number of entries in array
- * @name_skip: offset where the parameter name start in kparam[].name. Needed for built-in "modules"
+ * add_sysfs_param - add a parameter to sysfs
+ * @mk: struct module_kobject
+ * @kparam: the actual parameter definition to add to sysfs
+ * @name: name of parameter
*
- * Create a kobject for a (per-module) group of parameters, and create files
- * in sysfs. A pointer to the param_kobject is returned on success,
- * NULL if there's no parameter to export, or other ERR_PTR(err).
+ * Create a kobject if for a (per-module) parameter if mp NULL, and
+ * create file in sysfs. Returns an error on out of memory. Always cleans up
+ * if there's an error.
*/
-static __modinit struct module_param_attrs *
-param_sysfs_setup(struct module_kobject *mk,
- struct kernel_param *kparam,
- unsigned int num_params,
- unsigned int name_skip)
+static __modinit int add_sysfs_param(struct module_kobject *mk,
+ struct kernel_param *kp,
+ const char *name)
{
- struct module_param_attrs *mp;
- unsigned int valid_attrs = 0;
- unsigned int i, size[2];
- struct param_attribute *pattr;
- struct attribute **gattr;
- int err;
-
- for (i=0; i<num_params; i++) {
- if (kparam[i].perm)
- valid_attrs++;
+ struct module_param_attrs *new;
+ struct attribute **attrs;
+ int err, num;
+
+ /* We don't bother calling this with invisible parameters. */
+ BUG_ON(!kp->perm);
+
+ if (!mk->mp) {
+ num = 0;
+ attrs = NULL;
+ } else {
+ num = mk->mp->num;
+ attrs = mk->mp->grp.attrs;
}
- if (!valid_attrs)
- return NULL;
-
- size[0] = ALIGN(sizeof(*mp) +
- valid_attrs * sizeof(mp->attrs[0]),
- sizeof(mp->grp.attrs[0]));
- size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]);
-
- mp = kzalloc(size[0] + size[1], GFP_KERNEL);
- if (!mp)
- return ERR_PTR(-ENOMEM);
+ /* Enlarge. */
+ new = krealloc(mk->mp,
+ sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
+ GFP_KERNEL);
+ if (!new) {
+ kfree(mk->mp);
+ err = -ENOMEM;
+ goto fail;
+ }
+ attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
+ if (!attrs) {
+ err = -ENOMEM;
+ goto fail_free_new;
+ }
- mp->grp.name = "parameters";
- mp->grp.attrs = (void *)mp + size[0];
+ /* Sysfs wants everything zeroed. */
+ memset(new, 0, sizeof(*new));
+ memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
+ memset(&attrs[num], 0, sizeof(attrs[num]));
+ new->grp.name = "parameters";
+ new->grp.attrs = attrs;
+
+ /* Tack new one on the end. */
+ new->attrs[num].param = kp;
+ new->attrs[num].mattr.show = param_attr_show;
+ new->attrs[num].mattr.store = param_attr_store;
+ new->attrs[num].mattr.attr.name = (char *)name;
+ new->attrs[num].mattr.attr.mode = kp->perm;
+ new->num = num+1;
+
+ /* Fix up all the pointers, since krealloc can move us */
+ for (num = 0; num < new->num; num++)
+ new->grp.attrs[num] = &new->attrs[num].mattr.attr;
+ new->grp.attrs[num] = NULL;
+
+ mk->mp = new;
+ return 0;
- pattr = &mp->attrs[0];
- gattr = &mp->grp.attrs[0];
- for (i = 0; i < num_params; i++) {
- struct kernel_param *kp = &kparam[i];
- if (kp->perm) {
- pattr->param = kp;
- pattr->mattr.show = param_attr_show;
- pattr->mattr.store = param_attr_store;
- pattr->mattr.attr.name = (char *)&kp->name[name_skip];
- pattr->mattr.attr.mode = kp->perm;
- *(gattr++) = &(pattr++)->mattr.attr;
- }
- }
- *gattr = NULL;
+fail_free_new:
+ kfree(new);
+fail:
+ mk->mp = NULL;
+ return err;
+}
- if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) {
- kfree(mp);
- return ERR_PTR(err);
- }
- return mp;
+static void free_module_param_attrs(struct module_kobject *mk)
+{
+ kfree(mk->mp->grp.attrs);
+ kfree(mk->mp);
+ mk->mp = NULL;
}
#ifdef CONFIG_MODULES
@@ -506,21 +524,33 @@ param_sysfs_setup(struct module_kobject *mk,
* @kparam: module parameters (array)
* @num_params: number of module parameters
*
- * Adds sysfs entries for module parameters, and creates a link from
- * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/
+ * Adds sysfs entries for module parameters under
+ * /sys/module/[mod->name]/parameters/
*/
int module_param_sysfs_setup(struct module *mod,
struct kernel_param *kparam,
unsigned int num_params)
{
- struct module_param_attrs *mp;
+ int i, err;
+ bool params = false;
+
+ for (i = 0; i < num_params; i++) {
+ if (kparam[i].perm == 0)
+ continue;
+ err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
+ if (err)
+ return err;
+ params = true;
+ }
- mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0);
- if (IS_ERR(mp))
- return PTR_ERR(mp);
+ if (!params)
+ return 0;
- mod->param_attrs = mp;
- return 0;
+ /* Create the param group. */
+ err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
+ if (err)
+ free_module_param_attrs(&mod->mkobj);
+ return err;
}
/*
@@ -532,43 +562,55 @@ int module_param_sysfs_setup(struct module *mod,
*/
void module_param_sysfs_remove(struct module *mod)
{
- if (mod->param_attrs) {
- sysfs_remove_group(&mod->mkobj.kobj,
- &mod->param_attrs->grp);
+ if (mod->mkobj.mp) {
+ sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
/* We are positive that no one is using any param
* attrs at this point. Deallocate immediately. */
- kfree(mod->param_attrs);
- mod->param_attrs = NULL;
+ free_module_param_attrs(&mod->mkobj);
}
}
#endif
-/*
- * kernel_param_sysfs_setup - wrapper for built-in params support
- */
-static void __init kernel_param_sysfs_setup(const char *name,
- struct kernel_param *kparam,
- unsigned int num_params,
- unsigned int name_skip)
+static void __init kernel_add_sysfs_param(const char *name,
+ struct kernel_param *kparam,
+ unsigned int name_skip)
{
struct module_kobject *mk;
- int ret;
+ struct kobject *kobj;
+ int err;
- mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
- BUG_ON(!mk);
-
- mk->mod = THIS_MODULE;
- mk->kobj.kset = module_kset;
- ret = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, "%s", name);
- if (ret) {
- kobject_put(&mk->kobj);
- printk(KERN_ERR "Module '%s' failed to be added to sysfs, "
- "error number %d\n", name, ret);
- printk(KERN_ERR "The system will be unstable now.\n");
- return;
+ kobj = kset_find_obj(module_kset, name);
+ if (kobj) {
+ /* We already have one. Remove params so we can add more. */
+ mk = to_module_kobject(kobj);
+ /* We need to remove it before adding parameters. */
+ sysfs_remove_group(&mk->kobj, &mk->mp->grp);
+ } else {
+ mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
+ BUG_ON(!mk);
+
+ mk->mod = THIS_MODULE;
+ mk->kobj.kset = module_kset;
+ err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
+ "%s", name);
+ if (err) {
+ kobject_put(&mk->kobj);
+ printk(KERN_ERR "Module '%s' failed add to sysfs, "
+ "error number %d\n", name, err);
+ printk(KERN_ERR "The system will be unstable now.\n");
+ return;
+ }
+ /* So that exit path is even. */
+ kobject_get(&mk->kobj);
}
- param_sysfs_setup(mk, kparam, num_params, name_skip);
+
+ /* These should not fail at boot. */
+ err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
+ BUG_ON(err);
+ err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
+ BUG_ON(err);
kobject_uevent(&mk->kobj, KOBJ_ADD);
+ kobject_put(&mk->kobj);
}
/*
@@ -579,60 +621,36 @@ static void __init kernel_param_sysfs_setup(const char *name,
* The "module" name (KBUILD_MODNAME) is stored before a dot, the
* "parameter" name is stored behind a dot in kernel_param->name. So,
* extract the "module" name for all built-in kernel_param-eters,
- * and for all who have the same, call kernel_param_sysfs_setup.
+ * and for all who have the same, call kernel_add_sysfs_param.
*/
static void __init param_sysfs_builtin(void)
{
- struct kernel_param *kp, *kp_begin = NULL;
- unsigned int i, name_len, count = 0;
- char modname[MODULE_NAME_LEN + 1] = "";
+ struct kernel_param *kp;
+ unsigned int name_len;
+ char modname[MODULE_NAME_LEN];
- for (i=0; i < __stop___param - __start___param; i++) {
+ for (kp = __start___param; kp < __stop___param; kp++) {
char *dot;
- size_t max_name_len;
- kp = &__start___param[i];
- max_name_len =
- min_t(size_t, MODULE_NAME_LEN, strlen(kp->name));
+ if (kp->perm == 0)
+ continue;
- dot = memchr(kp->name, '.', max_name_len);
+ dot = strchr(kp->name, '.');
if (!dot) {
- DEBUGP("couldn't find period in first %d characters "
- "of %s\n", MODULE_NAME_LEN, kp->name);
- continue;
- }
- name_len = dot - kp->name;
-
- /* new kbuild_modname? */
- if (strlen(modname) != name_len
- || strncmp(modname, kp->name, name_len) != 0) {
- /* add a new kobject for previous kernel_params. */
- if (count)
- kernel_param_sysfs_setup(modname,
- kp_begin,
- count,
- strlen(modname)+1);
-
- strncpy(modname, kp->name, name_len);
- modname[name_len] = '\0';
- count = 0;
- kp_begin = kp;
+ /* This happens for core_param() */
+ strcpy(modname, "kernel");
+ name_len = 0;
+ } else {
+ name_len = dot - kp->name + 1;
+ strlcpy(modname, kp->name, name_len);
}
- count++;
+ kernel_add_sysfs_param(modname, kp, name_len);
}
-
- /* last kernel_params need to be registered as well */
- if (count)
- kernel_param_sysfs_setup(modname, kp_begin, count,
- strlen(modname)+1);
}
/* module-related sysfs stuff */
-#define to_module_attr(n) container_of(n, struct module_attribute, attr);
-#define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
-
static ssize_t module_attr_show(struct kobject *kobj,
struct attribute *attr,
char *buf)
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index af3c7ce..8aff79d 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -37,9 +37,13 @@ struct stop_machine_data {
/* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */
static unsigned int num_threads;
static atomic_t thread_ack;
-static struct completion finished;
static DEFINE_MUTEX(lock);
+static struct workqueue_struct *stop_machine_wq;
+static struct stop_machine_data active, idle;
+static const cpumask_t *active_cpus;
+static void *stop_machine_work;
+
static void set_state(enum stopmachine_state newstate)
{
/* Reset ack counter. */
@@ -51,21 +55,26 @@ static void set_state(enum stopmachine_state newstate)
/* Last one to ack a state moves to the next state. */
static void ack_state(void)
{
- if (atomic_dec_and_test(&thread_ack)) {
- /* If we're the last one to ack the EXIT, we're finished. */
- if (state == STOPMACHINE_EXIT)
- complete(&finished);
- else
- set_state(state + 1);
- }
+ if (atomic_dec_and_test(&thread_ack))
+ set_state(state + 1);
}
-/* This is the actual thread which stops the CPU. It exits by itself rather
- * than waiting for kthread_stop(), because it's easier for hotplug CPU. */
-static int stop_cpu(struct stop_machine_data *smdata)
+/* This is the actual function which stops the CPU. It runs
+ * in the context of a dedicated stopmachine workqueue. */
+static void stop_cpu(struct work_struct *unused)
{
enum stopmachine_state curstate = STOPMACHINE_NONE;
-
+ struct stop_machine_data *smdata = &idle;
+ int cpu = smp_processor_id();
+ int err;
+
+ if (!active_cpus) {
+ if (cpu == first_cpu(cpu_online_map))
+ smdata = &active;
+ } else {
+ if (cpu_isset(cpu, *active_cpus))
+ smdata = &active;
+ }
/* Simple state machine */
do {
/* Chill out and ensure we re-read stopmachine_state. */
@@ -78,9 +87,11 @@ static int stop_cpu(struct stop_machine_data *smdata)
hard_irq_disable();
break;
case STOPMACHINE_RUN:
- /* |= allows error detection if functions on
- * multiple CPUs. */
- smdata->fnret |= smdata->fn(smdata->data);
+ /* On multiple CPUs only a single error code
+ * is needed to tell that something failed. */
+ err = smdata->fn(smdata->data);
+ if (err)
+ smdata->fnret = err;
break;
default:
break;
@@ -90,7 +101,6 @@ static int stop_cpu(struct stop_machine_data *smdata)
} while (curstate != STOPMACHINE_EXIT);
local_irq_enable();
- do_exit(0);
}
/* Callback for CPUs which aren't supposed to do anything. */
@@ -101,78 +111,34 @@ static int chill(void *unused)
int __stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus)
{
- int i, err;
- struct stop_machine_data active, idle;
- struct task_struct **threads;
+ struct work_struct *sm_work;
+ int i;
+ /* Set up initial state. */
+ mutex_lock(&lock);
+ num_threads = num_online_cpus();
+ active_cpus = cpus;
active.fn = fn;
active.data = data;
active.fnret = 0;
idle.fn = chill;
idle.data = NULL;
- /* This could be too big for stack on large machines. */
- threads = kcalloc(NR_CPUS, sizeof(threads[0]), GFP_KERNEL);
- if (!threads)
- return -ENOMEM;
-
- /* Set up initial state. */
- mutex_lock(&lock);
- init_completion(&finished);
- num_threads = num_online_cpus();
set_state(STOPMACHINE_PREPARE);
- for_each_online_cpu(i) {
- struct stop_machine_data *smdata = &idle;
- struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
-
- if (!cpus) {
- if (i == first_cpu(cpu_online_map))
- smdata = &active;
- } else {
- if (cpu_isset(i, *cpus))
- smdata = &active;
- }
-
- threads[i] = kthread_create((void *)stop_cpu, smdata, "kstop%u",
- i);
- if (IS_ERR(threads[i])) {
- err = PTR_ERR(threads[i]);
- threads[i] = NULL;
- goto kill_threads;
- }
-
- /* Place it onto correct cpu. */
- kthread_bind(threads[i], i);
-
- /* Make it highest prio. */
- if (sched_setscheduler_nocheck(threads[i], SCHED_FIFO, ¶m))
- BUG();
- }
-
- /* We've created all the threads. Wake them all: hold this CPU so one
+ /* Schedule the stop_cpu work on all cpus: hold this CPU so one
* doesn't hit this CPU until we're ready. */
get_cpu();
- for_each_online_cpu(i)
- wake_up_process(threads[i]);
-
+ for_each_online_cpu(i) {
+ sm_work = percpu_ptr(stop_machine_work, i);
+ INIT_WORK(sm_work, stop_cpu);
+ queue_work_on(i, stop_machine_wq, sm_work);
+ }
/* This will release the thread on our CPU. */
put_cpu();
- wait_for_completion(&finished);
+ flush_workqueue(stop_machine_wq);
mutex_unlock(&lock);
-
- kfree(threads);
-
return active.fnret;
-
-kill_threads:
- for_each_online_cpu(i)
- if (threads[i])
- kthread_stop(threads[i]);
- mutex_unlock(&lock);
-
- kfree(threads);
- return err;
}
int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus)
@@ -187,3 +153,11 @@ int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus)
return ret;
}
EXPORT_SYMBOL_GPL(stop_machine);
+
+static int __init stop_machine_init(void)
+{
+ stop_machine_wq = create_rt_workqueue("kstop");
+ stop_machine_work = alloc_percpu(struct work_struct);
+ return 0;
+}
+early_initcall(stop_machine_init);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 714afad..f928f2a 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -62,6 +62,7 @@ struct workqueue_struct {
const char *name;
int singlethread;
int freezeable; /* Freeze threads during suspend */
+ int rt;
#ifdef CONFIG_LOCKDEP
struct lockdep_map lockdep_map;
#endif
@@ -766,6 +767,7 @@ init_cpu_workqueue(struct workqueue_struct *wq, int cpu)
static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
{
+ struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
struct workqueue_struct *wq = cwq->wq;
const char *fmt = is_single_threaded(wq) ? "%s" : "%s/%d";
struct task_struct *p;
@@ -781,7 +783,8 @@ static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
*/
if (IS_ERR(p))
return PTR_ERR(p);
-
+ if (cwq->wq->rt)
+ sched_setscheduler_nocheck(p, SCHED_FIFO, ¶m);
cwq->thread = p;
return 0;
@@ -801,6 +804,7 @@ static void start_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
struct workqueue_struct *__create_workqueue_key(const char *name,
int singlethread,
int freezeable,
+ int rt,
struct lock_class_key *key,
const char *lock_name)
{
@@ -822,6 +826,7 @@ struct workqueue_struct *__create_workqueue_key(const char *name,
lockdep_init_map(&wq->lockdep_map, lock_name, key, 0);
wq->singlethread = singlethread;
wq->freezeable = freezeable;
+ wq->rt = rt;
INIT_LIST_HEAD(&wq->list);
if (singlethread) {
--
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