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authorLinus Torvalds <torvalds@linux-foundation.org>2010-04-05 09:16:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-04-05 09:16:37 -0700
commit9e74e7c81a24aee66024fc477786bd1de84e293b (patch)
tree8f172b7e5a86fe6b51e46f1d219e9c0707beab60 /kernel
parent4946d54cb55e86a156216fcfeed5568514b0830f (diff)
parentd5e50daf92df8afcb701fd717b301985691e802f (diff)
downloadlwn-9e74e7c81a24aee66024fc477786bd1de84e293b.tar.gz
lwn-9e74e7c81a24aee66024fc477786bd1de84e293b.zip
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: module: add stub for is_module_percpu_address percpu, module: implement and use is_kernel/module_percpu_address() module: encapsulate percpu handling better and record percpu_size
Diffstat (limited to 'kernel')
-rw-r--r--kernel/lockdep.c21
-rw-r--r--kernel/module.c104
2 files changed, 78 insertions, 47 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index c927a549db2c..9bbb9c841e48 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -582,9 +582,6 @@ static int static_obj(void *obj)
unsigned long start = (unsigned long) &_stext,
end = (unsigned long) &_end,
addr = (unsigned long) obj;
-#ifdef CONFIG_SMP
- int i;
-#endif
/*
* static variable?
@@ -595,24 +592,16 @@ static int static_obj(void *obj)
if (arch_is_kernel_data(addr))
return 1;
-#ifdef CONFIG_SMP
/*
- * percpu var?
+ * in-kernel percpu var?
*/
- for_each_possible_cpu(i) {
- start = (unsigned long) &__per_cpu_start + per_cpu_offset(i);
- end = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM
- + per_cpu_offset(i);
-
- if ((addr >= start) && (addr < end))
- return 1;
- }
-#endif
+ if (is_kernel_percpu_address(addr))
+ return 1;
/*
- * module var?
+ * module static or percpu var?
*/
- return is_module_address(addr);
+ return is_module_address(addr) || is_module_percpu_address(addr);
}
/*
diff --git a/kernel/module.c b/kernel/module.c
index c968d3606dca..9f8d23d8b3a8 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -370,27 +370,33 @@ EXPORT_SYMBOL_GPL(find_module);
#ifdef CONFIG_SMP
-static void *percpu_modalloc(unsigned long size, unsigned long align,
- const char *name)
+static inline void __percpu *mod_percpu(struct module *mod)
{
- void *ptr;
+ return mod->percpu;
+}
+static int percpu_modalloc(struct module *mod,
+ unsigned long size, unsigned long align)
+{
if (align > PAGE_SIZE) {
printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
- name, align, PAGE_SIZE);
+ mod->name, align, PAGE_SIZE);
align = PAGE_SIZE;
}
- ptr = __alloc_reserved_percpu(size, align);
- if (!ptr)
+ mod->percpu = __alloc_reserved_percpu(size, align);
+ if (!mod->percpu) {
printk(KERN_WARNING
"Could not allocate %lu bytes percpu data\n", size);
- return ptr;
+ return -ENOMEM;
+ }
+ mod->percpu_size = size;
+ return 0;
}
-static void percpu_modfree(void *freeme)
+static void percpu_modfree(struct module *mod)
{
- free_percpu(freeme);
+ free_percpu(mod->percpu);
}
static unsigned int find_pcpusec(Elf_Ehdr *hdr,
@@ -400,24 +406,62 @@ static unsigned int find_pcpusec(Elf_Ehdr *hdr,
return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
}
-static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
+static void percpu_modcopy(struct module *mod,
+ const void *from, unsigned long size)
{
int cpu;
for_each_possible_cpu(cpu)
- memcpy(pcpudest + per_cpu_offset(cpu), from, size);
+ memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
+}
+
+/**
+ * is_module_percpu_address - test whether address is from module static percpu
+ * @addr: address to test
+ *
+ * Test whether @addr belongs to module static percpu area.
+ *
+ * RETURNS:
+ * %true if @addr is from module static percpu area
+ */
+bool is_module_percpu_address(unsigned long addr)
+{
+ struct module *mod;
+ unsigned int cpu;
+
+ preempt_disable();
+
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (!mod->percpu_size)
+ continue;
+ for_each_possible_cpu(cpu) {
+ void *start = per_cpu_ptr(mod->percpu, cpu);
+
+ if ((void *)addr >= start &&
+ (void *)addr < start + mod->percpu_size) {
+ preempt_enable();
+ return true;
+ }
+ }
+ }
+
+ preempt_enable();
+ return false;
}
#else /* ... !CONFIG_SMP */
-static inline void *percpu_modalloc(unsigned long size, unsigned long align,
- const char *name)
+static inline void __percpu *mod_percpu(struct module *mod)
{
return NULL;
}
-static inline void percpu_modfree(void *pcpuptr)
+static inline int percpu_modalloc(struct module *mod,
+ unsigned long size, unsigned long align)
+{
+ return -ENOMEM;
+}
+static inline void percpu_modfree(struct module *mod)
{
- BUG();
}
static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
@@ -425,12 +469,16 @@ static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
{
return 0;
}
-static inline void percpu_modcopy(void *pcpudst, const void *src,
- unsigned long size)
+static inline void percpu_modcopy(struct module *mod,
+ const void *from, unsigned long size)
{
/* pcpusec should be 0, and size of that section should be 0. */
BUG_ON(size != 0);
}
+bool is_module_percpu_address(unsigned long addr)
+{
+ return false;
+}
#endif /* CONFIG_SMP */
@@ -1400,8 +1448,7 @@ static void free_module(struct module *mod)
/* This may be NULL, but that's OK */
module_free(mod, mod->module_init);
kfree(mod->args);
- if (mod->percpu)
- percpu_modfree(mod->percpu);
+ percpu_modfree(mod);
#if defined(CONFIG_MODULE_UNLOAD)
if (mod->refptr)
free_percpu(mod->refptr);
@@ -1520,7 +1567,7 @@ static int simplify_symbols(Elf_Shdr *sechdrs,
default:
/* Divert to percpu allocation if a percpu var. */
if (sym[i].st_shndx == pcpuindex)
- secbase = (unsigned long)mod->percpu;
+ secbase = (unsigned long)mod_percpu(mod);
else
secbase = sechdrs[sym[i].st_shndx].sh_addr;
sym[i].st_value += secbase;
@@ -1954,7 +2001,7 @@ static noinline struct module *load_module(void __user *umod,
unsigned int modindex, versindex, infoindex, pcpuindex;
struct module *mod;
long err = 0;
- void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
+ void *ptr = NULL; /* Stops spurious gcc warning */
unsigned long symoffs, stroffs, *strmap;
mm_segment_t old_fs;
@@ -2094,15 +2141,11 @@ static noinline struct module *load_module(void __user *umod,
if (pcpuindex) {
/* We have a special allocation for this section. */
- percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
- sechdrs[pcpuindex].sh_addralign,
- mod->name);
- if (!percpu) {
- err = -ENOMEM;
+ err = percpu_modalloc(mod, sechdrs[pcpuindex].sh_size,
+ sechdrs[pcpuindex].sh_addralign);
+ if (err)
goto free_mod;
- }
sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
- mod->percpu = percpu;
}
/* Determine total sizes, and put offsets in sh_entsize. For now
@@ -2317,7 +2360,7 @@ static noinline struct module *load_module(void __user *umod,
sort_extable(mod->extable, mod->extable + mod->num_exentries);
/* Finally, copy percpu area over. */
- percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
+ percpu_modcopy(mod, (void *)sechdrs[pcpuindex].sh_addr,
sechdrs[pcpuindex].sh_size);
add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex,
@@ -2409,8 +2452,7 @@ static noinline struct module *load_module(void __user *umod,
module_free(mod, mod->module_core);
/* mod will be freed with core. Don't access it beyond this line! */
free_percpu:
- if (percpu)
- percpu_modfree(percpu);
+ percpu_modfree(mod);
free_mod:
kfree(args);
kfree(strmap);