mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-03 00:54:09 +08:00
d19e789f06
Linus pointed out that compiler.h - which is a key header that gets included in every
single one of the 28,000+ kernel files during a kernel build - was bloated in:
6553896666: ("vmlinux.lds.h: Create section for protection against instrumentation")
Linus noted:
> I have pulled this, but do we really want to add this to a header file
> that is _so_ core that it gets included for basically every single
> file built?
>
> I don't even see those instrumentation_begin/end() things used
> anywhere right now.
>
> It seems excessive. That 53 lines is maybe not a lot, but it pushed
> that header file to over 12kB, and while it's mostly comments, it's
> extra IO and parsing basically for _every_ single file compiled in the
> kernel.
>
> For what appears to be absolutely zero upside right now, and I really
> don't see why this should be in such a core header file!
Move these primitives into a new header: <linux/instrumentation.h>, and include that
header in the headers that make use of it.
Unfortunately one of these headers is asm-generic/bug.h, which does get included
in a lot of places, similarly to compiler.h. So the de-bloating effect isn't as
good as we'd like it to be - but at least the interfaces are defined separately.
No change to functionality intended.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200604071921.GA1361070@gmail.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
247 lines
6.8 KiB
C
247 lines
6.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_GENERIC_BUG_H
|
|
#define _ASM_GENERIC_BUG_H
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/instrumentation.h>
|
|
|
|
#define CUT_HERE "------------[ cut here ]------------\n"
|
|
|
|
#ifdef CONFIG_GENERIC_BUG
|
|
#define BUGFLAG_WARNING (1 << 0)
|
|
#define BUGFLAG_ONCE (1 << 1)
|
|
#define BUGFLAG_DONE (1 << 2)
|
|
#define BUGFLAG_NO_CUT_HERE (1 << 3) /* CUT_HERE already sent */
|
|
#define BUGFLAG_TAINT(taint) ((taint) << 8)
|
|
#define BUG_GET_TAINT(bug) ((bug)->flags >> 8)
|
|
#endif
|
|
|
|
#ifndef __ASSEMBLY__
|
|
#include <linux/kernel.h>
|
|
|
|
#ifdef CONFIG_BUG
|
|
|
|
#ifdef CONFIG_GENERIC_BUG
|
|
struct bug_entry {
|
|
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
|
|
unsigned long bug_addr;
|
|
#else
|
|
signed int bug_addr_disp;
|
|
#endif
|
|
#ifdef CONFIG_DEBUG_BUGVERBOSE
|
|
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
|
|
const char *file;
|
|
#else
|
|
signed int file_disp;
|
|
#endif
|
|
unsigned short line;
|
|
#endif
|
|
unsigned short flags;
|
|
};
|
|
#endif /* CONFIG_GENERIC_BUG */
|
|
|
|
/*
|
|
* Don't use BUG() or BUG_ON() unless there's really no way out; one
|
|
* example might be detecting data structure corruption in the middle
|
|
* of an operation that can't be backed out of. If the (sub)system
|
|
* can somehow continue operating, perhaps with reduced functionality,
|
|
* it's probably not BUG-worthy.
|
|
*
|
|
* If you're tempted to BUG(), think again: is completely giving up
|
|
* really the *only* solution? There are usually better options, where
|
|
* users don't need to reboot ASAP and can mostly shut down cleanly.
|
|
*/
|
|
#ifndef HAVE_ARCH_BUG
|
|
#define BUG() do { \
|
|
printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
|
|
barrier_before_unreachable(); \
|
|
panic("BUG!"); \
|
|
} while (0)
|
|
#endif
|
|
|
|
#ifndef HAVE_ARCH_BUG_ON
|
|
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
|
|
#endif
|
|
|
|
/*
|
|
* WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
|
|
* significant kernel issues that need prompt attention if they should ever
|
|
* appear at runtime.
|
|
*
|
|
* Do not use these macros when checking for invalid external inputs
|
|
* (e.g. invalid system call arguments, or invalid data coming from
|
|
* network/devices), and on transient conditions like ENOMEM or EAGAIN.
|
|
* These macros should be used for recoverable kernel issues only.
|
|
* For invalid external inputs, transient conditions, etc use
|
|
* pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary.
|
|
* Do not include "BUG"/"WARNING" in format strings manually to make these
|
|
* conditions distinguishable from kernel issues.
|
|
*
|
|
* Use the versions with printk format strings to provide better diagnostics.
|
|
*/
|
|
#ifndef __WARN_FLAGS
|
|
extern __printf(4, 5)
|
|
void warn_slowpath_fmt(const char *file, const int line, unsigned taint,
|
|
const char *fmt, ...);
|
|
#define __WARN() __WARN_printf(TAINT_WARN, NULL)
|
|
#define __WARN_printf(taint, arg...) do { \
|
|
instrumentation_begin(); \
|
|
warn_slowpath_fmt(__FILE__, __LINE__, taint, arg); \
|
|
instrumentation_end(); \
|
|
} while (0)
|
|
#else
|
|
extern __printf(1, 2) void __warn_printk(const char *fmt, ...);
|
|
#define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
|
|
#define __WARN_printf(taint, arg...) do { \
|
|
instrumentation_begin(); \
|
|
__warn_printk(arg); \
|
|
__WARN_FLAGS(BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\
|
|
instrumentation_end(); \
|
|
} while (0)
|
|
#define WARN_ON_ONCE(condition) ({ \
|
|
int __ret_warn_on = !!(condition); \
|
|
if (unlikely(__ret_warn_on)) \
|
|
__WARN_FLAGS(BUGFLAG_ONCE | \
|
|
BUGFLAG_TAINT(TAINT_WARN)); \
|
|
unlikely(__ret_warn_on); \
|
|
})
|
|
#endif
|
|
|
|
/* used internally by panic.c */
|
|
struct warn_args;
|
|
struct pt_regs;
|
|
|
|
void __warn(const char *file, int line, void *caller, unsigned taint,
|
|
struct pt_regs *regs, struct warn_args *args);
|
|
|
|
#ifndef WARN_ON
|
|
#define WARN_ON(condition) ({ \
|
|
int __ret_warn_on = !!(condition); \
|
|
if (unlikely(__ret_warn_on)) \
|
|
__WARN(); \
|
|
unlikely(__ret_warn_on); \
|
|
})
|
|
#endif
|
|
|
|
#ifndef WARN
|
|
#define WARN(condition, format...) ({ \
|
|
int __ret_warn_on = !!(condition); \
|
|
if (unlikely(__ret_warn_on)) \
|
|
__WARN_printf(TAINT_WARN, format); \
|
|
unlikely(__ret_warn_on); \
|
|
})
|
|
#endif
|
|
|
|
#define WARN_TAINT(condition, taint, format...) ({ \
|
|
int __ret_warn_on = !!(condition); \
|
|
if (unlikely(__ret_warn_on)) \
|
|
__WARN_printf(taint, format); \
|
|
unlikely(__ret_warn_on); \
|
|
})
|
|
|
|
#ifndef WARN_ON_ONCE
|
|
#define WARN_ON_ONCE(condition) ({ \
|
|
static bool __section(.data.once) __warned; \
|
|
int __ret_warn_once = !!(condition); \
|
|
\
|
|
if (unlikely(__ret_warn_once && !__warned)) { \
|
|
__warned = true; \
|
|
WARN_ON(1); \
|
|
} \
|
|
unlikely(__ret_warn_once); \
|
|
})
|
|
#endif
|
|
|
|
#define WARN_ONCE(condition, format...) ({ \
|
|
static bool __section(.data.once) __warned; \
|
|
int __ret_warn_once = !!(condition); \
|
|
\
|
|
if (unlikely(__ret_warn_once && !__warned)) { \
|
|
__warned = true; \
|
|
WARN(1, format); \
|
|
} \
|
|
unlikely(__ret_warn_once); \
|
|
})
|
|
|
|
#define WARN_TAINT_ONCE(condition, taint, format...) ({ \
|
|
static bool __section(.data.once) __warned; \
|
|
int __ret_warn_once = !!(condition); \
|
|
\
|
|
if (unlikely(__ret_warn_once && !__warned)) { \
|
|
__warned = true; \
|
|
WARN_TAINT(1, taint, format); \
|
|
} \
|
|
unlikely(__ret_warn_once); \
|
|
})
|
|
|
|
#else /* !CONFIG_BUG */
|
|
#ifndef HAVE_ARCH_BUG
|
|
#define BUG() do {} while (1)
|
|
#endif
|
|
|
|
#ifndef HAVE_ARCH_BUG_ON
|
|
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
|
|
#endif
|
|
|
|
#ifndef HAVE_ARCH_WARN_ON
|
|
#define WARN_ON(condition) ({ \
|
|
int __ret_warn_on = !!(condition); \
|
|
unlikely(__ret_warn_on); \
|
|
})
|
|
#endif
|
|
|
|
#ifndef WARN
|
|
#define WARN(condition, format...) ({ \
|
|
int __ret_warn_on = !!(condition); \
|
|
no_printk(format); \
|
|
unlikely(__ret_warn_on); \
|
|
})
|
|
#endif
|
|
|
|
#define WARN_ON_ONCE(condition) WARN_ON(condition)
|
|
#define WARN_ONCE(condition, format...) WARN(condition, format)
|
|
#define WARN_TAINT(condition, taint, format...) WARN(condition, format)
|
|
#define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format)
|
|
|
|
#endif
|
|
|
|
/*
|
|
* WARN_ON_SMP() is for cases that the warning is either
|
|
* meaningless for !SMP or may even cause failures.
|
|
* It can also be used with values that are only defined
|
|
* on SMP:
|
|
*
|
|
* struct foo {
|
|
* [...]
|
|
* #ifdef CONFIG_SMP
|
|
* int bar;
|
|
* #endif
|
|
* };
|
|
*
|
|
* void func(struct foo *zoot)
|
|
* {
|
|
* WARN_ON_SMP(!zoot->bar);
|
|
*
|
|
* For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
|
|
* and should be a nop and return false for uniprocessor.
|
|
*
|
|
* if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
|
|
* and x is true.
|
|
*/
|
|
#ifdef CONFIG_SMP
|
|
# define WARN_ON_SMP(x) WARN_ON(x)
|
|
#else
|
|
/*
|
|
* Use of ({0;}) because WARN_ON_SMP(x) may be used either as
|
|
* a stand alone line statement or as a condition in an if ()
|
|
* statement.
|
|
* A simple "0" would cause gcc to give a "statement has no effect"
|
|
* warning.
|
|
*/
|
|
# define WARN_ON_SMP(x) ({0;})
|
|
#endif
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
#endif
|