@@ -1,6 +1,8 @@
#ifndef _ASM_ARM_JUMP_LABEL_H
#define _ASM_ARM_JUMP_LABEL_H
+#include <asm/tables.h>
+
#ifndef __ASSEMBLY__
#include <linux/types.h>
@@ -12,7 +14,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran
{
asm_volatile_goto("1:\n\t"
WASM(nop) "\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
".word 1b, %l[l_yes], %c0\n\t"
".popsection\n\t"
: : "i" (&((char *)key)[branch]) : : l_yes);
@@ -26,7 +28,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool
{
asm_volatile_goto("1:\n\t"
WASM(b) " %l[l_yes]\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
".word 1b, %l[l_yes], %c0\n\t"
".popsection\n\t"
: : "i" (&((char *)key)[branch]) : : l_yes);
@@ -19,6 +19,8 @@
#ifndef __ASM_JUMP_LABEL_H
#define __ASM_JUMP_LABEL_H
+#include <asm/tables.h>
+
#ifndef __ASSEMBLY__
#include <linux/types.h>
@@ -29,7 +31,7 @@
static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
{
asm goto("1: nop\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
".align 3\n\t"
".quad 1b, %l[l_yes], %c0\n\t"
".popsection\n\t"
@@ -43,7 +45,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran
static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
{
asm goto("1: b %l[l_yes]\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
".align 3\n\t"
".quad 1b, %l[l_yes], %c0\n\t"
".popsection\n\t"
@@ -8,6 +8,8 @@
#ifndef _ASM_MIPS_JUMP_LABEL_H
#define _ASM_MIPS_JUMP_LABEL_H
+#include <asm/tables.h>
+
#ifndef __ASSEMBLY__
#include <linux/types.h>
@@ -30,7 +32,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran
{
asm_volatile_goto("1:\t" NOP_INSN "\n\t"
"nop\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
WORD_INSN " 1b, %l[l_yes], %0\n\t"
".popsection\n\t"
: : "i" (&((char *)key)[branch]) : : l_yes);
@@ -44,7 +46,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool
{
asm_volatile_goto("1:\tj %l[l_yes]\n\t"
"nop\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
WORD_INSN " 1b, %l[l_yes], %0\n\t"
".popsection\n\t"
: : "i" (&((char *)key)[branch]) : : l_yes);
@@ -10,6 +10,8 @@
* 2 of the License, or (at your option) any later version.
*/
+#include <asm/tables.h>
+
#ifndef __ASSEMBLY__
#include <linux/types.h>
@@ -23,7 +25,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran
{
asm_volatile_goto("1:\n\t"
"nop # arch_static_branch\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
".popsection \n\t"
: : "i" (&((char *)key)[branch]) : : l_yes);
@@ -37,7 +39,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool
{
asm_volatile_goto("1:\n\t"
"b %l[l_yes] # arch_static_branch_jump\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
".popsection \n\t"
: : "i" (&((char *)key)[branch]) : : l_yes);
@@ -62,7 +64,7 @@ struct jump_entry {
#else
#define ARCH_STATIC_BRANCH(LABEL, KEY) \
1098: nop; \
- .pushsection __jump_table, "aw"; \
+ push_section_tbl_any(.data, __jump_table, aw); \
FTR_ENTRY_LONG 1098b, LABEL, KEY; \
.popsection
#endif
@@ -1,6 +1,8 @@
#ifndef _ASM_S390_JUMP_LABEL_H
#define _ASM_S390_JUMP_LABEL_H
+#include <asm/tables.h>
+
#ifndef __ASSEMBLY__
#include <linux/types.h>
@@ -16,7 +18,7 @@
static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
{
asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n"
- ".pushsection __jump_table, \"aw\"\n"
+ push_section_tbl_any(.data, __jump_table, aw)
".balign 8\n"
".quad 0b, %l[label], %0\n"
".popsection\n"
@@ -30,7 +32,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran
static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
{
asm_volatile_goto("0: brcl 15, %l[label]\n"
- ".pushsection __jump_table, \"aw\"\n"
+ push_section_tbl_any(.data, __jump_table, aw)
".balign 8\n"
".quad 0b, %l[label], %0\n"
".popsection\n"
@@ -1,6 +1,8 @@
#ifndef _ASM_SPARC_JUMP_LABEL_H
#define _ASM_SPARC_JUMP_LABEL_H
+#include <asm/tables.h>
+
#ifndef __ASSEMBLY__
#include <linux/types.h>
@@ -12,7 +14,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran
asm_volatile_goto("1:\n\t"
"nop\n\t"
"nop\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
".align 4\n\t"
".word 1b, %l[l_yes], %c0\n\t"
".popsection \n\t"
@@ -28,7 +30,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool
asm_volatile_goto("1:\n\t"
"b %l[l_yes]\n\t"
"nop\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
".align 4\n\t"
".word 1b, %l[l_yes], %c0\n\t"
".popsection \n\t"
@@ -16,6 +16,7 @@
#define _ASM_TILE_JUMP_LABEL_H
#include <arch/opcode.h>
+#include <asm/tables.h>
#define JUMP_LABEL_NOP_SIZE TILE_BUNDLE_SIZE_IN_BYTES
@@ -24,7 +25,7 @@ static __always_inline bool arch_static_branch(struct static_key *key,
{
asm_volatile_goto("1:\n\t"
"nop" "\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
".quad 1b, %l[l_yes], %0 + %1 \n\t"
".popsection\n\t"
: : "i" (key), "i" (branch) : : l_yes);
@@ -38,7 +39,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key,
{
asm_volatile_goto("1:\n\t"
"j %l[l_yes]" "\n\t"
- ".pushsection __jump_table, \"aw\"\n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
".quad 1b, %l[l_yes], %0 + %1 \n\t"
".popsection\n\t"
: : "i" (key), "i" (branch) : : l_yes);
@@ -1,6 +1,8 @@
#ifndef _ASM_X86_JUMP_LABEL_H
#define _ASM_X86_JUMP_LABEL_H
+#include <asm/tables.h>
+
#ifndef HAVE_JUMP_LABEL
/*
* For better or for worse, if jump labels (the gcc extension) are missing,
@@ -34,7 +36,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran
{
asm_volatile_goto("1:"
".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
- ".pushsection __jump_table, \"aw\" \n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
_ASM_ALIGN "\n\t"
_ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t"
".popsection \n\t"
@@ -50,7 +52,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool
asm_volatile_goto("1:"
".byte 0xe9\n\t .long %l[l_yes] - 2f\n\t"
"2:\n\t"
- ".pushsection __jump_table, \"aw\" \n\t"
+ push_section_tbl_any(.data, __jump_table, aw)
_ASM_ALIGN "\n\t"
_ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t"
".popsection \n\t"
@@ -85,7 +87,7 @@ struct jump_entry {
.else
.byte STATIC_KEY_INIT_NOP
.endif
- .pushsection __jump_table, "aw"
+ push_section_tbl_any(.data, __jump_table, aw)
_ASM_ALIGN
_ASM_PTR .Lstatic_jump_\@, \target, \key
.popsection
@@ -101,7 +103,7 @@ struct jump_entry {
.long \target - .Lstatic_jump_after_\@
.Lstatic_jump_after_\@:
.endif
- .pushsection __jump_table, "aw"
+ push_section_tbl_any(.data, __jump_table, aw)
_ASM_ALIGN
_ASM_PTR .Lstatic_jump_\@, \target, \key + 1
.popsection
@@ -216,11 +216,6 @@
*(.data.unlikely) \
STRUCT_ALIGN(); \
*(__tracepoints) \
- /* implement dynamic printk debug */ \
- . = ALIGN(8); \
- VMLINUX_SYMBOL(__start___jump_table) = .; \
- KEEP(*(__jump_table)) \
- VMLINUX_SYMBOL(__stop___jump_table) = .; \
. = ALIGN(8); \
VMLINUX_SYMBOL(__start___verbose) = .; \
KEEP(*(__verbose)) \
@@ -117,6 +117,7 @@ enum jump_label_type {
struct module;
#ifdef HAVE_JUMP_LABEL
+#include <linux/tables.h>
#define JUMP_TYPE_FALSE 0UL
#define JUMP_TYPE_TRUE 1UL
@@ -132,8 +133,7 @@ static __always_inline bool static_key_true(struct static_key *key)
return !arch_static_branch(key, true);
}
-extern struct jump_entry __start___jump_table[];
-extern struct jump_entry __stop___jump_table[];
+DECLARE_LINKTABLE(struct jump_entry, __jump_table);
extern void jump_label_init(void);
extern void jump_label_lock(void);
@@ -15,9 +15,12 @@
#include <linux/static_key.h>
#include <linux/jump_label_ratelimit.h>
#include <linux/bug.h>
+#include <linux/tables.h>
#ifdef HAVE_JUMP_LABEL
+DEFINE_LINKTABLE(struct jump_entry, __jump_table);
+
/* mutex to protect coming/going of the the jump_label table */
static DEFINE_MUTEX(jump_label_mutex);
@@ -274,8 +277,6 @@ static void __jump_label_update(struct static_key *key,
void __init jump_label_init(void)
{
- struct jump_entry *iter_start = __start___jump_table;
- struct jump_entry *iter_stop = __stop___jump_table;
struct static_key *key = NULL;
struct jump_entry *iter;
@@ -292,9 +293,10 @@ void __init jump_label_init(void)
return;
jump_label_lock();
- jump_label_sort_entries(iter_start, iter_stop);
+ jump_label_sort_entries(LINKTABLE_START(__jump_table),
+ LINKTABLE_END(__jump_table));
- for (iter = iter_start; iter < iter_stop; iter++) {
+ LINKTABLE_FOR_EACH(iter, __jump_table) {
struct static_key *iterk;
/* rewrite NOPs */
@@ -539,8 +541,9 @@ early_initcall(jump_label_init_module);
*/
int jump_label_text_reserved(void *start, void *end)
{
- int ret = __jump_label_text_reserved(__start___jump_table,
- __stop___jump_table, start, end);
+ int ret = __jump_label_text_reserved(LINKTABLE_START(__jump_table),
+ LINKTABLE_END(__jump_table),
+ start, end);
if (ret)
return ret;
@@ -553,7 +556,7 @@ int jump_label_text_reserved(void *start, void *end)
static void jump_label_update(struct static_key *key)
{
- struct jump_entry *stop = __stop___jump_table;
+ struct jump_entry *stop = LINKTABLE_END(__jump_table);
struct jump_entry *entry = static_key_entries(key);
#ifdef CONFIG_MODULES
struct module *mod;
@@ -16,6 +16,7 @@ SECTIONS {
__kcrctab_unused 0 : { *(SORT(___kcrctab_unused+*)) }
__kcrctab_unused_gpl 0 : { *(SORT(___kcrctab_unused_gpl+*)) }
__kcrctab_gpl_future 0 : { *(SORT(___kcrctab_gpl_future+*)) }
+ __jump_table 0 : { *(SORT(.data..tbl.__jump_table.*)) }
. = ALIGN(8);
.init_array 0 : { *(SORT(.init_array.*)) *(.init_array) }
@@ -63,7 +63,7 @@ struct special_entry entries[] = {
.feature = ALT_FEATURE_OFFSET,
},
{
- .sec = "__jump_table",
+ .sec = ".data..tbl.__jump_table.any",
.jump_or_nop = true,
.size = JUMP_ENTRY_SIZE,
.orig = JUMP_ORIG_OFFSET,
Move the __jump_table from the a custom section solution to a generic solution, this avoiding extra vmlinux.lds.h customizations. This also demos the use of the .data linker table and of the shared asm call push_section_tbl(). Built-in kernel functionality was tested with CONFIG_STATIC_KEYS_SELFTEST. Moduler kernel functionality was tested with CONFIG_TEST_STATIC_KEYS. Both work as expected. Since __jump_table sections are also supported per module this also required expanding module-common.lds.S to capture and fold all .data.tlb.__jump_table.* onto the the section __jump_table -- in this case for modules need to keep a reference in place, given the alternative is to use DEFINE_LINKTABLE(struct jump_entry, __jump_table) per module -- and later through macro hacks instantiate the jump entries per module upon init. This is doable but we'd loose out on the sorting of the table using the linker, to sort we'd always still need to expand the module common linker script. An alternative mechanism is possible which would make these custom module sections extensions dynamic without requiring manual changes, this however is best done later through a separate evolution once linker tables are in place. A careful reviewer may note that some architectures use "\n\t" to separate asm code, while others just use a new line. Upon review last time it was deemed reasonable to for all architectures to just use "\n", this is defined as ASM_CMD_SEP, and if an architecture needs to override they can do so on their architecture sections.h prior to including asm-generic/sections.h v5: o Use ..tbl instead of .tbl as suggested by Nicholas Piggin. This is the typical way to avoid clash with compiler generated section. o Replace section macros with section names o Use LINKTABLE_START() and LINKTABLE_END() o fixed tile jump label port -- tile got jump label support as of commit 65a792e84f25d1 ("tile/jump_label: add jump label support for TILE-Gx"), as such we just needed to adjust the asm to account for the new linker table API use. This commit was merged as of v4.5-rc1. v4: o Some architectures allow linker scripts to follow including header files, some others do not, so if you need a helper on a linker script you need to explicitly include it. So for instance although scripts/module-common.lds.S includes <asm/tables.h> and this file includes <asm/section-core.h>, you still need to explicitly include it on the linker script. This issue is present on ARM. o as per Josh Poimboeuf open code the section table name instead of including the kernel section headers, the simplicity and independence from the kernel is preferred. v3: o More elaborate tests performed o first modular support use case, module tested was CONFIG_TEST_STATIC_KEYS (lib/test_static_keys.ko), this required us to extend module-common.lds.S o use generic push_section_tbl_any() for all architectures o Makes use of ASM_CMD_SEP to enable architectures to override later if needed o guard tables.h inclusion and table definition with __KERNEL__ v2: introduced in this series Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> --- arch/arm/include/asm/jump_label.h | 6 ++++-- arch/arm64/include/asm/jump_label.h | 6 ++++-- arch/mips/include/asm/jump_label.h | 6 ++++-- arch/powerpc/include/asm/jump_label.h | 8 +++++--- arch/s390/include/asm/jump_label.h | 6 ++++-- arch/sparc/include/asm/jump_label.h | 6 ++++-- arch/tile/include/asm/jump_label.h | 5 +++-- arch/x86/include/asm/jump_label.h | 10 ++++++---- include/asm-generic/vmlinux.lds.h | 5 ----- include/linux/jump_label.h | 4 ++-- kernel/jump_label.c | 17 ++++++++++------- scripts/module-common.lds | 1 + tools/objtool/special.c | 2 +- 13 files changed, 48 insertions(+), 34 deletions(-)