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-rw-r--r--arch/parisc/include/asm/module.h6
-rw-r--r--arch/parisc/kernel/module.c216
-rw-r--r--include/linux/moduleloader.h3
-rw-r--r--include/linux/stop_machine.h22
-rw-r--r--init/Kconfig6
-rw-r--r--kernel/cpu.c6
-rw-r--r--kernel/module.c59
-rw-r--r--kernel/stop_machine.c55
8 files changed, 258 insertions, 115 deletions
diff --git a/arch/parisc/include/asm/module.h b/arch/parisc/include/asm/module.h
index c2cb49e934c1..1f4123427ea0 100644
--- a/arch/parisc/include/asm/module.h
+++ b/arch/parisc/include/asm/module.h
@@ -23,8 +23,10 @@ struct mod_arch_specific
{
unsigned long got_offset, got_count, got_max;
unsigned long fdesc_offset, fdesc_count, fdesc_max;
- unsigned long stub_offset, stub_count, stub_max;
- unsigned long init_stub_offset, init_stub_count, init_stub_max;
+ struct {
+ unsigned long stub_offset;
+ unsigned int stub_entries;
+ } *section;
int unwind_section;
struct unwind_table *unwind;
};
diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index 44138c3e6ea7..9013243cecca 100644
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c
@@ -6,6 +6,7 @@
*
* Linux/PA-RISC Project (http://www.parisc-linux.org/)
* Copyright (C) 2003 Randolph Chung <tausq at debian . org>
+ * Copyright (C) 2008 Helge Deller <deller@gmx.de>
*
*
* This program is free software; you can redistribute it and/or modify
@@ -24,6 +25,19 @@
*
*
* Notes:
+ * - PLT stub handling
+ * On 32bit (and sometimes 64bit) and with big kernel modules like xfs or
+ * ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may
+ * fail to reach their PLT stub if we only create one big stub array for
+ * all sections at the beginning of the core or init section.
+ * Instead we now insert individual PLT stub entries directly in front of
+ * of the code sections where the stubs are actually called.
+ * This reduces the distance between the PCREL location and the stub entry
+ * so that the relocations can be fulfilled.
+ * While calculating the final layout of the kernel module in memory, the
+ * kernel module loader calls arch_mod_section_prepend() to request the
+ * to be reserved amount of memory in front of each individual section.
+ *
* - SEGREL32 handling
* We are not doing SEGREL32 handling correctly. According to the ABI, we
* should do a value offset, like this:
@@ -58,9 +72,13 @@
#define DEBUGP(fmt...)
#endif
+#define RELOC_REACHABLE(val, bits) \
+ (( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \
+ ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \
+ 0 : 1)
+
#define CHECK_RELOC(val, bits) \
- if ( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \
- ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) { \
+ if (!RELOC_REACHABLE(val, bits)) { \
printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \
me->name, strtab + sym->st_name, (unsigned long)val, bits); \
return -ENOEXEC; \
@@ -92,13 +110,6 @@ static inline int in_local(struct module *me, void *loc)
return in_init(me, loc) || in_core(me, loc);
}
-static inline int in_local_section(struct module *me, void *loc, void *dot)
-{
- return (in_init(me, loc) && in_init(me, dot)) ||
- (in_core(me, loc) && in_core(me, dot));
-}
-
-
#ifndef CONFIG_64BIT
struct got_entry {
Elf32_Addr addr;
@@ -258,23 +269,42 @@ static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
/* Free memory returned from module_alloc */
void module_free(struct module *mod, void *module_region)
{
+ kfree(mod->arch.section);
+ mod->arch.section = NULL;
+
vfree(module_region);
/* FIXME: If module_region == mod->init_region, trim exception
table entries. */
}
+/* Additional bytes needed in front of individual sections */
+unsigned int arch_mod_section_prepend(struct module *mod,
+ unsigned int section)
+{
+ /* size needed for all stubs of this section (including
+ * one additional for correct alignment of the stubs) */
+ return (mod->arch.section[section].stub_entries + 1)
+ * sizeof(struct stub_entry);
+}
+
#define CONST
int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
CONST Elf_Shdr *sechdrs,
CONST char *secstrings,
struct module *me)
{
- unsigned long gots = 0, fdescs = 0, stubs = 0, init_stubs = 0;
+ unsigned long gots = 0, fdescs = 0, len;
unsigned int i;
+ len = hdr->e_shnum * sizeof(me->arch.section[0]);
+ me->arch.section = kzalloc(len, GFP_KERNEL);
+ if (!me->arch.section)
+ return -ENOMEM;
+
for (i = 1; i < hdr->e_shnum; i++) {
- const Elf_Rela *rels = (void *)hdr + sechdrs[i].sh_offset;
+ const Elf_Rela *rels = (void *)sechdrs[i].sh_addr;
unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels);
+ unsigned int count, s;
if (strncmp(secstrings + sechdrs[i].sh_name,
".PARISC.unwind", 14) == 0)
@@ -290,11 +320,23 @@ int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
*/
gots += count_gots(rels, nrels);
fdescs += count_fdescs(rels, nrels);
- if(strncmp(secstrings + sechdrs[i].sh_name,
- ".rela.init", 10) == 0)
- init_stubs += count_stubs(rels, nrels);
- else
- stubs += count_stubs(rels, nrels);
+
+ /* XXX: By sorting the relocs and finding duplicate entries
+ * we could reduce the number of necessary stubs and save
+ * some memory. */
+ count = count_stubs(rels, nrels);
+ if (!count)
+ continue;
+
+ /* so we need relocation stubs. reserve necessary memory. */
+ /* sh_info gives the section for which we need to add stubs. */
+ s = sechdrs[i].sh_info;
+
+ /* each code section should only have one relocation section */
+ WARN_ON(me->arch.section[s].stub_entries);
+
+ /* store number of stubs we need for this section */
+ me->arch.section[s].stub_entries += count;
}
/* align things a bit */
@@ -306,18 +348,8 @@ int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
me->arch.fdesc_offset = me->core_size;
me->core_size += fdescs * sizeof(Elf_Fdesc);
- me->core_size = ALIGN(me->core_size, 16);
- me->arch.stub_offset = me->core_size;
- me->core_size += stubs * sizeof(struct stub_entry);
-
- me->init_size = ALIGN(me->init_size, 16);
- me->arch.init_stub_offset = me->init_size;
- me->init_size += init_stubs * sizeof(struct stub_entry);
-
me->arch.got_max = gots;
me->arch.fdesc_max = fdescs;
- me->arch.stub_max = stubs;
- me->arch.init_stub_max = init_stubs;
return 0;
}
@@ -380,23 +412,27 @@ enum elf_stub_type {
};
static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
- enum elf_stub_type stub_type, int init_section)
+ enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
{
- unsigned long i;
struct stub_entry *stub;
- if(init_section) {
- i = me->arch.init_stub_count++;
- BUG_ON(me->arch.init_stub_count > me->arch.init_stub_max);
- stub = me->module_init + me->arch.init_stub_offset +
- i * sizeof(struct stub_entry);
- } else {
- i = me->arch.stub_count++;
- BUG_ON(me->arch.stub_count > me->arch.stub_max);
- stub = me->module_core + me->arch.stub_offset +
- i * sizeof(struct stub_entry);
+ /* initialize stub_offset to point in front of the section */
+ if (!me->arch.section[targetsec].stub_offset) {
+ loc0 -= (me->arch.section[targetsec].stub_entries + 1) *
+ sizeof(struct stub_entry);
+ /* get correct alignment for the stubs */
+ loc0 = ALIGN(loc0, sizeof(struct stub_entry));
+ me->arch.section[targetsec].stub_offset = loc0;
}
+ /* get address of stub entry */
+ stub = (void *) me->arch.section[targetsec].stub_offset;
+ me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry);
+
+ /* do not write outside available stub area */
+ BUG_ON(0 == me->arch.section[targetsec].stub_entries--);
+
+
#ifndef CONFIG_64BIT
/* for 32-bit the stub looks like this:
* ldil L'XXX,%r1
@@ -489,15 +525,19 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
Elf32_Addr val;
Elf32_Sword addend;
Elf32_Addr dot;
+ Elf_Addr loc0;
+ unsigned int targetsec = sechdrs[relsec].sh_info;
//unsigned long dp = (unsigned long)$global$;
register unsigned long dp asm ("r27");
DEBUGP("Applying relocate section %u to %u\n", relsec,
- sechdrs[relsec].sh_info);
+ targetsec);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
/* This is where to make the change */
- loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ loc = (void *)sechdrs[targetsec].sh_addr
+ rel[i].r_offset;
+ /* This is the start of the target section */
+ loc0 = sechdrs[targetsec].sh_addr;
/* This is the symbol it is referring to */
sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+ ELF32_R_SYM(rel[i].r_info);
@@ -569,19 +609,32 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
break;
case R_PARISC_PCREL17F:
/* 17-bit PC relative address */
- val = get_stub(me, val, addend, ELF_STUB_GOT, in_init(me, loc));
+ /* calculate direct call offset */
+ val += addend;
val = (val - dot - 8)/4;
- CHECK_RELOC(val, 17)
+ if (!RELOC_REACHABLE(val, 17)) {
+ /* direct distance too far, create
+ * stub entry instead */
+ val = get_stub(me, sym->st_value, addend,
+ ELF_STUB_DIRECT, loc0, targetsec);
+ val = (val - dot - 8)/4;
+ CHECK_RELOC(val, 17);
+ }
*loc = (*loc & ~0x1f1ffd) | reassemble_17(val);
break;
case R_PARISC_PCREL22F:
/* 22-bit PC relative address; only defined for pa20 */
- val = get_stub(me, val, addend, ELF_STUB_GOT, in_init(me, loc));
- DEBUGP("STUB FOR %s loc %lx+%lx at %lx\n",
- strtab + sym->st_name, (unsigned long)loc, addend,
- val)
+ /* calculate direct call offset */
+ val += addend;
val = (val - dot - 8)/4;
- CHECK_RELOC(val, 22);
+ if (!RELOC_REACHABLE(val, 22)) {
+ /* direct distance too far, create
+ * stub entry instead */
+ val = get_stub(me, sym->st_value, addend,
+ ELF_STUB_DIRECT, loc0, targetsec);
+ val = (val - dot - 8)/4;
+ CHECK_RELOC(val, 22);
+ }
*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
break;
@@ -610,13 +663,17 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
Elf64_Addr val;
Elf64_Sxword addend;
Elf64_Addr dot;
+ Elf_Addr loc0;
+ unsigned int targetsec = sechdrs[relsec].sh_info;
DEBUGP("Applying relocate section %u to %u\n", relsec,
- sechdrs[relsec].sh_info);
+ targetsec);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
/* This is where to make the change */
- loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ loc = (void *)sechdrs[targetsec].sh_addr
+ rel[i].r_offset;
+ /* This is the start of the target section */
+ loc0 = sechdrs[targetsec].sh_addr;
/* This is the symbol it is referring to */
sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
+ ELF64_R_SYM(rel[i].r_info);
@@ -672,42 +729,40 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
DEBUGP("PCREL22F Symbol %s loc %p val %lx\n",
strtab + sym->st_name,
loc, val);
+ val += addend;
/* can we reach it locally? */
- if(!in_local_section(me, (void *)val, (void *)dot)) {
-
- if (in_local(me, (void *)val))
- /* this is the case where the
- * symbol is local to the
- * module, but in a different
- * section, so stub the jump
- * in case it's more than 22
- * bits away */
- val = get_stub(me, val, addend, ELF_STUB_DIRECT,
- in_init(me, loc));
- else if (strncmp(strtab + sym->st_name, "$$", 2)
+ if (in_local(me, (void *)val)) {
+ /* this is the case where the symbol is local
+ * to the module, but in a different section,
+ * so stub the jump in case it's more than 22
+ * bits away */
+ val = (val - dot - 8)/4;
+ if (!RELOC_REACHABLE(val, 22)) {
+ /* direct distance too far, create
+ * stub entry instead */
+ val = get_stub(me, sym->st_value,
+ addend, ELF_STUB_DIRECT,
+ loc0, targetsec);
+ } else {
+ /* Ok, we can reach it directly. */
+ val = sym->st_value;
+ val += addend;
+ }
+ } else {
+ val = sym->st_value;
+ if (strncmp(strtab + sym->st_name, "$$", 2)
== 0)
val = get_stub(me, val, addend, ELF_STUB_MILLI,
- in_init(me, loc));
+ loc0, targetsec);
else
val = get_stub(me, val, addend, ELF_STUB_GOT,
- in_init(me, loc));
+ loc0, targetsec);
}
DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n",
strtab + sym->st_name, loc, sym->st_value,
addend, val);
- /* FIXME: local symbols work as long as the
- * core and init pieces aren't separated too
- * far. If this is ever broken, you will trip
- * the check below. The way to fix it would
- * be to generate local stubs to go between init
- * and core */
- if((Elf64_Sxword)(val - dot - 8) > 0x800000 -1 ||
- (Elf64_Sxword)(val - dot - 8) < -0x800000) {
- printk(KERN_ERR "Module %s, symbol %s is out of range for PCREL22F relocation\n",
- me->name, strtab + sym->st_name);
- return -ENOEXEC;
- }
val = (val - dot - 8)/4;
+ CHECK_RELOC(val, 22);
*loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
break;
case R_PARISC_DIR64:
@@ -794,12 +849,8 @@ int module_finalize(const Elf_Ehdr *hdr,
addr = (u32 *)entry->addr;
printk("INSNS: %x %x %x %x\n",
addr[0], addr[1], addr[2], addr[3]);
- printk("stubs used %ld, stubs max %ld\n"
- "init_stubs used %ld, init stubs max %ld\n"
- "got entries used %ld, gots max %ld\n"
+ printk("got entries used %ld, gots max %ld\n"
"fdescs used %ld, fdescs max %ld\n",
- me->arch.stub_count, me->arch.stub_max,
- me->arch.init_stub_count, me->arch.init_stub_max,
me->arch.got_count, me->arch.got_max,
me->arch.fdesc_count, me->arch.fdesc_max);
#endif
@@ -829,7 +880,10 @@ int module_finalize(const Elf_Ehdr *hdr,
me->name, me->arch.got_count, MAX_GOTS);
return -EINVAL;
}
-
+
+ kfree(me->arch.section);
+ me->arch.section = NULL;
+
/* no symbol table */
if(symhdr == NULL)
return 0;
diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h
index eb1033957486..c1f40c2f7ffb 100644
--- a/include/linux/moduleloader.h
+++ b/include/linux/moduleloader.h
@@ -13,6 +13,9 @@ int module_frob_arch_sections(Elf_Ehdr *hdr,
char *secstrings,
struct module *mod);
+/* Additional bytes needed by arch in front of individual sections */
+unsigned int arch_mod_section_prepend(struct module *mod, unsigned int section);
+
/* Allocator used for allocating struct module, core sections and init
sections. Returns NULL on failure. */
void *module_alloc(unsigned long size);
diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h
index 74d59a641362..baba3a23a814 100644
--- a/include/linux/stop_machine.h
+++ b/include/linux/stop_machine.h
@@ -35,6 +35,24 @@ int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus);
* won't come or go while it's being called. Used by hotplug cpu.
*/
int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus);
+
+/**
+ * stop_machine_create: create all stop_machine threads
+ *
+ * Description: This causes all stop_machine threads to be created before
+ * stop_machine actually gets called. This can be used by subsystems that
+ * need a non failing stop_machine infrastructure.
+ */
+int stop_machine_create(void);
+
+/**
+ * stop_machine_destroy: destroy all stop_machine threads
+ *
+ * Description: This causes all stop_machine threads which were created with
+ * stop_machine_create to be destroyed again.
+ */
+void stop_machine_destroy(void);
+
#else
static inline int stop_machine(int (*fn)(void *), void *data,
@@ -46,5 +64,9 @@ static inline int stop_machine(int (*fn)(void *), void *data,
local_irq_enable();
return ret;
}
+
+static inline int stop_machine_create(void) { return 0; }
+static inline void stop_machine_destroy(void) { }
+
#endif /* CONFIG_SMP */
#endif /* _LINUX_STOP_MACHINE */
diff --git a/init/Kconfig b/init/Kconfig
index f6281711166d..52847eec7398 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -916,12 +916,6 @@ config MODULE_SRCVERSION_ALL
the version). With this option, such a "srcversion" field
will be created for all modules. If unsure, say N.
-config KMOD
- def_bool y
- help
- This is being removed soon. These days, CONFIG_MODULES
- implies CONFIG_KMOD, so use that instead.
-
endif # MODULES
config INIT_ALL_POSSIBLE
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 47fff3b63cbf..30e74dd6d01b 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -269,8 +269,11 @@ out_release:
int __ref cpu_down(unsigned int cpu)
{
- int err = 0;
+ int err;
+ err = stop_machine_create();
+ if (err)
+ return err;
cpu_maps_update_begin();
if (cpu_hotplug_disabled) {
@@ -297,6 +300,7 @@ int __ref cpu_down(unsigned int cpu)
out:
cpu_maps_update_done();
+ stop_machine_destroy();
return err;
}
EXPORT_SYMBOL(cpu_down);
diff --git a/kernel/module.c b/kernel/module.c
index dd2a54155b54..f47cce910f25 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -757,8 +757,16 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
return -EFAULT;
name[MODULE_NAME_LEN-1] = '\0';
- if (mutex_lock_interruptible(&module_mutex) != 0)
- return -EINTR;
+ /* Create stop_machine threads since free_module relies on
+ * a non-failing stop_machine call. */
+ ret = stop_machine_create();
+ if (ret)
+ return ret;
+
+ if (mutex_lock_interruptible(&module_mutex) != 0) {
+ ret = -EINTR;
+ goto out_stop;
+ }
mod = find_module(name);
if (!mod) {
@@ -817,10 +825,12 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
out:
mutex_unlock(&module_mutex);
+out_stop:
+ stop_machine_destroy();
return ret;
}
-static void print_unload_info(struct seq_file *m, struct module *mod)
+static inline void print_unload_info(struct seq_file *m, struct module *mod)
{
struct module_use *use;
int printed_something = 0;
@@ -893,7 +903,7 @@ void module_put(struct module *module)
EXPORT_SYMBOL(module_put);
#else /* !CONFIG_MODULE_UNLOAD */
-static void print_unload_info(struct seq_file *m, struct module *mod)
+static inline void print_unload_info(struct seq_file *m, struct module *mod)
{
/* We don't know the usage count, or what modules are using. */
seq_printf(m, " - -");
@@ -1578,11 +1588,21 @@ static int simplify_symbols(Elf_Shdr *sechdrs,
return ret;
}
+/* Additional bytes needed by arch in front of individual sections */
+unsigned int __weak arch_mod_section_prepend(struct module *mod,
+ unsigned int section)
+{
+ /* default implementation just returns zero */
+ return 0;
+}
+
/* Update size with this section: return offset. */
-static long get_offset(unsigned int *size, Elf_Shdr *sechdr)
+static long get_offset(struct module *mod, unsigned int *size,
+ Elf_Shdr *sechdr, unsigned int section)
{
long ret;
+ *size += arch_mod_section_prepend(mod, section);
ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
*size = ret + sechdr->sh_size;
return ret;
@@ -1622,7 +1642,7 @@ static void layout_sections(struct module *mod,
|| strncmp(secstrings + s->sh_name,
".init", 5) == 0)
continue;
- s->sh_entsize = get_offset(&mod->core_size, s);
+ s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
DEBUGP("\t%s\n", secstrings + s->sh_name);
}
if (m == 0)
@@ -1640,7 +1660,7 @@ static void layout_sections(struct module *mod,
|| strncmp(secstrings + s->sh_name,
".init", 5) != 0)
continue;
- s->sh_entsize = (get_offset(&mod->init_size, s)
+ s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
| INIT_OFFSET_MASK);
DEBUGP("\t%s\n", secstrings + s->sh_name);
}
@@ -1725,15 +1745,15 @@ static const struct kernel_symbol *lookup_symbol(const char *name,
return NULL;
}
-static int is_exported(const char *name, const struct module *mod)
+static int is_exported(const char *name, unsigned long value,
+ const struct module *mod)
{
- if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
- return 1;
+ const struct kernel_symbol *ks;
+ if (!mod)
+ ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
else
- if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
- return 1;
- else
- return 0;
+ ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
+ return ks != NULL && ks->value == value;
}
/* As per nm */
@@ -1865,6 +1885,13 @@ static noinline struct module *load_module(void __user *umod,
/* vmalloc barfs on "unusual" numbers. Check here */
if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
return ERR_PTR(-ENOMEM);
+
+ /* Create stop_machine threads since the error path relies on
+ * a non-failing stop_machine call. */
+ err = stop_machine_create();
+ if (err)
+ goto free_hdr;
+
if (copy_from_user(hdr, umod, len) != 0) {
err = -EFAULT;
goto free_hdr;
@@ -2248,6 +2275,7 @@ static noinline struct module *load_module(void __user *umod,
/* Get rid of temporary copy */
vfree(hdr);
+ stop_machine_destroy();
/* Done! */
return mod;
@@ -2270,6 +2298,7 @@ static noinline struct module *load_module(void __user *umod,
kfree(args);
free_hdr:
vfree(hdr);
+ stop_machine_destroy();
return ERR_PTR(err);
truncated:
@@ -2504,7 +2533,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
KSYM_NAME_LEN);
strlcpy(module_name, mod->name, MODULE_NAME_LEN);
- *exported = is_exported(name, mod);
+ *exported = is_exported(name, *value, mod);
preempt_enable();
return 0;
}
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 286c41722e8c..0cd415ee62a2 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -38,7 +38,10 @@ struct stop_machine_data {
static unsigned int num_threads;
static atomic_t thread_ack;
static DEFINE_MUTEX(lock);
-
+/* setup_lock protects refcount, stop_machine_wq and stop_machine_work. */
+static DEFINE_MUTEX(setup_lock);
+/* Users of stop_machine. */
+static int refcount;
static struct workqueue_struct *stop_machine_wq;
static struct stop_machine_data active, idle;
static const cpumask_t *active_cpus;
@@ -109,6 +112,43 @@ static int chill(void *unused)
return 0;
}
+int stop_machine_create(void)
+{
+ mutex_lock(&setup_lock);
+ if (refcount)
+ goto done;
+ stop_machine_wq = create_rt_workqueue("kstop");
+ if (!stop_machine_wq)
+ goto err_out;
+ stop_machine_work = alloc_percpu(struct work_struct);
+ if (!stop_machine_work)
+ goto err_out;
+done:
+ refcount++;
+ mutex_unlock(&setup_lock);
+ return 0;
+
+err_out:
+ if (stop_machine_wq)
+ destroy_workqueue(stop_machine_wq);
+ mutex_unlock(&setup_lock);
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(stop_machine_create);
+
+void stop_machine_destroy(void)
+{
+ mutex_lock(&setup_lock);
+ refcount--;
+ if (refcount)
+ goto done;
+ destroy_workqueue(stop_machine_wq);
+ free_percpu(stop_machine_work);
+done:
+ mutex_unlock(&setup_lock);
+}
+EXPORT_SYMBOL_GPL(stop_machine_destroy);
+
int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
{
struct work_struct *sm_work;
@@ -146,19 +186,14 @@ int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
{
int ret;
+ ret = stop_machine_create();
+ if (ret)
+ return ret;
/* No CPUs can come up or down during this. */
get_online_cpus();
ret = __stop_machine(fn, data, cpus);
put_online_cpus();
-
+ stop_machine_destroy();
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;
-}
-core_initcall(stop_machine_init);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-25 19:35:45 +0000