The patch titled
Subject: lib/dynamic_debug.c: introduce CONFIG_DYNAMIC_DEBUG_RELATIVE_POINTERS
has been added to the -mm tree. Its filename is
dynamic_debug-introduce-config_dynamic_debug_relative_pointers.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/dynamic_debug-introduce-config_dynamic_debug_relative_pointers.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/dynamic_debug-introduce-config_dynamic_debug_relative_pointers.patch
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there every 3-4 working days
------------------------------------------------------
From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Subject: lib/dynamic_debug.c: introduce CONFIG_DYNAMIC_DEBUG_RELATIVE_POINTERS
Based on the same idea for struct bug_entry, an architecture can opt-in to
use relative pointers in struct _ddebug. It only makes sense for 64 bit
architectures, where one saves 16 bytes per entry (out of 40 or 56,
depending on CONFIG_JUMP_LABEL). The architecture is responsible for
providing a suitable DEFINE_DYNAMIC_DEBUG_METADATA macro in
<asm/dynamic_debug.h>.
Link: http://lkml.kernel.org/r/20190409212517.7321-7-linux@xxxxxxxxxxxxxxxxxx
Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Acked-by: Jason Baron <jbaron@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxx>
Cc: David Miller <davem@xxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/dynamic_debug.h | 14 ++++++++++++++
lib/Kconfig.debug | 3 +++
lib/dynamic_debug.c | 20 ++++++++++++++++++++
3 files changed, 37 insertions(+)
--- a/include/linux/dynamic_debug.h~dynamic_debug-introduce-config_dynamic_debug_relative_pointers
+++ a/include/linux/dynamic_debug.h
@@ -16,10 +16,17 @@ struct _ddebug {
* These fields are used to drive the user interface
* for selecting and displaying debug callsites.
*/
+#ifdef CONFIG_DYNAMIC_DEBUG_RELATIVE_POINTERS
+ signed int modname_disp;
+ signed int function_disp;
+ signed int filename_disp;
+ signed int format_disp;
+#else
const char *modname;
const char *function;
const char *filename;
const char *format;
+#endif
/*
* The flags field controls the behaviour at the callsite.
* The bits here are changed dynamically when the user
@@ -70,6 +77,12 @@ void __dynamic_netdev_dbg(struct _ddebug
const struct net_device *dev,
const char *fmt, ...);
+#ifdef CONFIG_DYNAMIC_DEBUG_RELATIVE_POINTERS
+#include <asm/dynamic_debug.h>
+#ifndef DEFINE_DYNAMIC_DEBUG_METADATA
+# error "asm/dynamic_debug.h must provide definition of DEFINE_DYNAMIC_DEBUG_METADATA"
+#endif
+#else
#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
static struct _ddebug __aligned(8) \
__attribute__((section("__verbose"))) name = { \
@@ -80,6 +93,7 @@ void __dynamic_netdev_dbg(struct _ddebug
.flags_lineno = _DPRINTK_FLAGS_LINENO_INIT, \
_DPRINTK_KEY_INIT \
}
+#endif
#ifdef CONFIG_JUMP_LABEL
--- a/lib/dynamic_debug.c~dynamic_debug-introduce-config_dynamic_debug_relative_pointers
+++ a/lib/dynamic_debug.c
@@ -37,6 +37,24 @@
#include <linux/device.h>
#include <linux/netdevice.h>
+#ifdef CONFIG_DYNAMIC_DEBUG_RELATIVE_POINTERS
+static inline const char *dd_modname(const struct _ddebug *dd)
+{
+ return (const char *)dd + dd->modname_disp;
+}
+static inline const char *dd_function(const struct _ddebug *dd)
+{
+ return (const char *)dd + dd->function_disp;
+}
+static inline const char *dd_filename(const struct _ddebug *dd)
+{
+ return (const char *)dd + dd->filename_disp;
+}
+static inline const char *dd_format(const struct _ddebug *dd)
+{
+ return (const char *)dd + dd->format_disp;
+}
+#else
static inline const char *dd_modname(const struct _ddebug *dd)
{
return dd->modname;
@@ -53,6 +71,8 @@ static inline const char *dd_format(cons
{
return dd->format;
}
+#endif
+
static inline unsigned dd_lineno(const struct _ddebug *dd)
{
return dd->flags_lineno >> 8;
--- a/lib/Kconfig.debug~dynamic_debug-introduce-config_dynamic_debug_relative_pointers
+++ a/lib/Kconfig.debug
@@ -163,6 +163,9 @@ config DYNAMIC_DEBUG
See Documentation/admin-guide/dynamic-debug-howto.rst for additional
information.
+config DYNAMIC_DEBUG_RELATIVE_POINTERS
+ bool
+
endmenu # "printk and dmesg options"
menu "Compile-time checks and compiler options"
_
Patches currently in -mm which might be from linux@xxxxxxxxxxxxxxxxxx are
linux-deviceh-use-unique-identifier-for-each-struct-_ddebug.patch
linux-neth-use-unique-identifier-for-each-struct-_ddebug.patch
linux-printkh-use-unique-identifier-for-each-struct-_ddebug.patch
dynamic_debug-introduce-accessors-for-string-members-of-struct-_ddebug.patch
dynamic_debug-drop-use-of-bitfields-in-struct-_ddebug.patch
dynamic_debug-introduce-config_dynamic_debug_relative_pointers.patch
dynamic_debug-add-asm-generic-implementation-for-dynamic_debug_relative_pointers.patch
x86-64-select-dynamic_debug_relative_pointers.patch
arm64-select-dynamic_debug_relative_pointers.patch
powerpc-select-dynamic_debug_relative_pointers-for-ppc64.patch
lib-bitmapc-remove-unused-export_symbols.patch
lib-bitmapc-guard-exotic-bitmap-functions-by-config_numa.patch
bitopsh-sanitize-rotate-primitives.patch
