@@ -216,10 +216,6 @@
*(.data.unlikely) \
STRUCT_ALIGN(); \
*(__tracepoints) \
- . = ALIGN(8); \
- VMLINUX_SYMBOL(__start___verbose) = .; \
- KEEP(*(__verbose)) \
- VMLINUX_SYMBOL(__stop___verbose) = .; \
LIKELY_PROFILE() \
BRANCH_PROFILE() \
TRACE_PRINTKS() \
@@ -4,6 +4,7 @@
#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
#include <linux/jump_label.h>
#endif
+#include <linux/tables.h>
/*
* An instance of this structure is created in a special
@@ -50,6 +51,7 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,
const char *modname);
#if defined(CONFIG_DYNAMIC_DEBUG)
+DECLARE_LINKTABLE(struct _ddebug, __verbose);
extern int ddebug_remove_module(const char *mod_name);
extern __printf(2, 3)
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
@@ -71,8 +73,7 @@ void __dynamic_netdev_dbg(struct _ddebug *descriptor,
const char *fmt, ...);
#define DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, key, init) \
- static struct _ddebug __aligned(8) \
- __attribute__((section("__verbose"))) name = { \
+ static LINKTABLE(__verbose, SECTION_ORDER_ANY) name = { \
.modname = KBUILD_MODNAME, \
.function = __func__, \
.filename = __FILE__, \
@@ -37,8 +37,7 @@
#include <linux/device.h>
#include <linux/netdevice.h>
-extern struct _ddebug __start___verbose[];
-extern struct _ddebug __stop___verbose[];
+DEFINE_LINKTABLE(struct _ddebug, __verbose);
struct ddebug_table {
struct list_head link;
@@ -978,14 +977,14 @@ static int __init dynamic_debug_init(void)
int n = 0, entries = 0, modct = 0;
int verbose_bytes = 0;
- if (__start___verbose == __stop___verbose) {
- pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
+ if (LINKTABLE_EMPTY(__verbose)) {
+ pr_warn("dynamic debug linker table empty on CONFIG_DYNAMIC_DEBUG build\n");
return 1;
}
- iter = __start___verbose;
+ iter = LINKTABLE_START(__verbose);
modname = iter->modname;
iter_start = iter;
- for (; iter < __stop___verbose; iter++) {
+ LINKTABLE_FOR_EACH(iter, __verbose) {
entries++;
verbose_bytes += strlen(iter->modname) + strlen(iter->function)
+ strlen(iter->filename) + strlen(iter->format);
@@ -1008,7 +1007,7 @@ static int __init dynamic_debug_init(void)
ddebug_init_success = 1;
vpr_info("%d modules, %d entries and %d bytes in ddebug tables, %d bytes in (readonly) verbose section\n",
modct, entries, (int)(modct * sizeof(struct ddebug_table)),
- verbose_bytes + (int)(__stop___verbose - __start___verbose));
+ verbose_bytes + (int)(LINKTABLE_SIZE(__verbose)));
/* apply ddebug_query boot param, dont unload tables on err */
if (ddebug_setup_string[0] != '\0') {
@@ -17,6 +17,7 @@ SECTIONS {
__kcrctab_unused_gpl 0 : { *(SORT(___kcrctab_unused_gpl+*)) }
__kcrctab_gpl_future 0 : { *(SORT(___kcrctab_gpl_future+*)) }
__jump_table 0 : { *(SORT(.data..tbl.__jump_table.*)) }
+ __verbose 0 : { *(SORT(.data..tbl.__verbose.*)) }
. = ALIGN(8);
.init_array 0 : { *(SORT(.init_array.*)) *(.init_array) }
This removes the custom vmlinux.lds.h hacks and uses the generalized solution for .data entries. There is much more potential for further fine tuning here in the future though. For instance, linker tables enable an extra postfix for order level annotations, this could easily be used as the KBUILD_MODNAME and with a bit of linker table changes we may be able to get a direct O(1) count of the entries for that KBUILD_MODNAME: it would just be a count on the number of entries for the given order level. This should help make dynamic_debug_init() cleaner and also reduce the amount of time it takes at boot time. Instead of iterating over each print until we have all for a KBUILD_MODNAME, we'd instead directly operate on each KBUILD_MODNAME directly. We can work on this later to make this change easier to review. Tested dynamic debug with dyndbg query and debugfs control and it works as expected, for both built-in code and modules. 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, use LINKTABLE_EMPTY(), LINKTABLE_START() v4: fix compilation on blackfin v3: added modular support v2: introduced this patch into the series Cc: Barry Song <barry.song@analog.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Steven Miao <realmz6@gmail.com> Cc: Michael Matz <matz@suse.de> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> --- include/asm-generic/vmlinux.lds.h | 4 ---- include/linux/dynamic_debug.h | 5 +++-- lib/dynamic_debug.c | 13 ++++++------- scripts/module-common.lds | 1 + 4 files changed, 10 insertions(+), 13 deletions(-)