WSL2-Linux-Kernel/include/linux/bug.h

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[PATCH] Generic BUG implementation This patch adds common handling for kernel BUGs, for use by architectures as they wish. The code is derived from arch/powerpc. The advantages of having common BUG handling are: - consistent BUG reporting across architectures - shared implementation of out-of-line file/line data - implement CONFIG_DEBUG_BUGVERBOSE consistently This means that in inline impact of BUG is just the illegal instruction itself, which is an improvement for i386 and x86-64. A BUG is represented in the instruction stream as an illegal instruction, which has file/line information associated with it. This extra information is stored in the __bug_table section in the ELF file. When the kernel gets an illegal instruction, it first confirms it might possibly be from a BUG (ie, in kernel mode, the right illegal instruction). It then calls report_bug(). This searches __bug_table for a matching instruction pointer, and if found, prints the corresponding file/line information. If report_bug() determines that it wasn't a BUG which caused the trap, it returns BUG_TRAP_TYPE_NONE. Some architectures (powerpc) implement WARN using the same mechanism; if the illegal instruction was the result of a WARN, then report_bug(Q) returns CONFIG_DEBUG_BUGVERBOSE; otherwise it returns BUG_TRAP_TYPE_BUG. lib/bug.c keeps a list of loaded modules which can be searched for __bug_table entries. The architecture must call module_bug_finalize()/module_bug_cleanup() from its corresponding module_finalize/cleanup functions. Unsetting CONFIG_DEBUG_BUGVERBOSE will reduce the kernel size by some amount. At the very least, filename and line information will not be recorded for each but, but architectures may decide to store no extra information per BUG at all. Unfortunately, gcc doesn't have a general way to mark an asm() as noreturn, so architectures will generally have to include an infinite loop (or similar) in the BUG code, so that gcc knows execution won't continue beyond that point. gcc does have a __builtin_trap() operator which may be useful to achieve the same effect, unfortunately it cannot be used to actually implement the BUG itself, because there's no way to get the instruction's address for use in generating the __bug_table entry. [randy.dunlap@oracle.com: Handle BUG=n, GENERIC_BUG=n to prevent build errors] [bunk@stusta.de: include/linux/bug.h must always #include <linux/module.h] Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Andi Kleen <ak@muc.de> Cc: Hugh Dickens <hugh@veritas.com> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 13:36:19 +03:00
#ifndef _LINUX_BUG_H
#define _LINUX_BUG_H
#include <asm/bug.h>
#include <linux/compiler.h>
[PATCH] Generic BUG implementation This patch adds common handling for kernel BUGs, for use by architectures as they wish. The code is derived from arch/powerpc. The advantages of having common BUG handling are: - consistent BUG reporting across architectures - shared implementation of out-of-line file/line data - implement CONFIG_DEBUG_BUGVERBOSE consistently This means that in inline impact of BUG is just the illegal instruction itself, which is an improvement for i386 and x86-64. A BUG is represented in the instruction stream as an illegal instruction, which has file/line information associated with it. This extra information is stored in the __bug_table section in the ELF file. When the kernel gets an illegal instruction, it first confirms it might possibly be from a BUG (ie, in kernel mode, the right illegal instruction). It then calls report_bug(). This searches __bug_table for a matching instruction pointer, and if found, prints the corresponding file/line information. If report_bug() determines that it wasn't a BUG which caused the trap, it returns BUG_TRAP_TYPE_NONE. Some architectures (powerpc) implement WARN using the same mechanism; if the illegal instruction was the result of a WARN, then report_bug(Q) returns CONFIG_DEBUG_BUGVERBOSE; otherwise it returns BUG_TRAP_TYPE_BUG. lib/bug.c keeps a list of loaded modules which can be searched for __bug_table entries. The architecture must call module_bug_finalize()/module_bug_cleanup() from its corresponding module_finalize/cleanup functions. Unsetting CONFIG_DEBUG_BUGVERBOSE will reduce the kernel size by some amount. At the very least, filename and line information will not be recorded for each but, but architectures may decide to store no extra information per BUG at all. Unfortunately, gcc doesn't have a general way to mark an asm() as noreturn, so architectures will generally have to include an infinite loop (or similar) in the BUG code, so that gcc knows execution won't continue beyond that point. gcc does have a __builtin_trap() operator which may be useful to achieve the same effect, unfortunately it cannot be used to actually implement the BUG itself, because there's no way to get the instruction's address for use in generating the __bug_table entry. [randy.dunlap@oracle.com: Handle BUG=n, GENERIC_BUG=n to prevent build errors] [bunk@stusta.de: include/linux/bug.h must always #include <linux/module.h] Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Andi Kleen <ak@muc.de> Cc: Hugh Dickens <hugh@veritas.com> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 13:36:19 +03:00
enum bug_trap_type {
BUG_TRAP_TYPE_NONE = 0,
BUG_TRAP_TYPE_WARN = 1,
BUG_TRAP_TYPE_BUG = 2,
};
struct pt_regs;
#ifdef __CHECKER__
#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
#define BUILD_BUG_ON_ZERO(e) (0)
#define BUILD_BUG_ON_NULL(e) ((void*)0)
#define BUILD_BUG_ON_INVALID(e) (0)
bug.h, compiler.h: introduce compiletime_assert & BUILD_BUG_ON_MSG Introduce compiletime_assert to compiler.h, which moves the details of how to break a build and emit an error message for a specific compiler to the headers where these details should be. Following in the tradition of the POSIX assert macro, compiletime_assert creates a build-time error when the supplied condition is *false*. Next, we add BUILD_BUG_ON_MSG to bug.h which simply wraps compiletime_assert, inverting the logic, so that it fails when the condition is *true*, consistent with the language "build bug on." This macro allows you to specify the error message you want emitted when the supplied condition is true. Finally, we remove all other code from bug.h that mucks with these details (BUILD_BUG & BUILD_BUG_ON), and have them all call BUILD_BUG_ON_MSG. This not only reduces source code bloat, but also prevents the possibility of code being changed for one macro and not for the other (which was previously the case for BUILD_BUG and BUILD_BUG_ON). Since __compiletime_error_fallback is now only used in compiler.h, I'm considering it a private macro and removing the double negation that's now extraneous. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Daniel Santos <daniel.santos@pobox.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: David Rientjes <rientjes@google.com> Cc: Joe Perches <joe@perches.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-22 04:41:55 +04:00
#define BUILD_BUG_ON_MSG(cond, msg) (0)
#define BUILD_BUG_ON(condition) (0)
#define BUILD_BUG() (0)
#else /* __CHECKER__ */
/* Force a compilation error if a constant expression is not a power of 2 */
#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
/* Force a compilation error if condition is true, but also produce a
result (of value 0 and type size_t), so the expression can be used
e.g. in a structure initializer (or where-ever else comma expressions
aren't permitted). */
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
/*
* BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
* expression but avoids the generation of any code, even if that expression
* has side-effects.
*/
#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
bug.h, compiler.h: introduce compiletime_assert & BUILD_BUG_ON_MSG Introduce compiletime_assert to compiler.h, which moves the details of how to break a build and emit an error message for a specific compiler to the headers where these details should be. Following in the tradition of the POSIX assert macro, compiletime_assert creates a build-time error when the supplied condition is *false*. Next, we add BUILD_BUG_ON_MSG to bug.h which simply wraps compiletime_assert, inverting the logic, so that it fails when the condition is *true*, consistent with the language "build bug on." This macro allows you to specify the error message you want emitted when the supplied condition is true. Finally, we remove all other code from bug.h that mucks with these details (BUILD_BUG & BUILD_BUG_ON), and have them all call BUILD_BUG_ON_MSG. This not only reduces source code bloat, but also prevents the possibility of code being changed for one macro and not for the other (which was previously the case for BUILD_BUG and BUILD_BUG_ON). Since __compiletime_error_fallback is now only used in compiler.h, I'm considering it a private macro and removing the double negation that's now extraneous. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Daniel Santos <daniel.santos@pobox.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: David Rientjes <rientjes@google.com> Cc: Joe Perches <joe@perches.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-22 04:41:55 +04:00
/**
* BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
* error message.
* @condition: the condition which the compiler should know is false.
*
* See BUILD_BUG_ON for description.
*/
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
/**
* BUILD_BUG_ON - break compile if a condition is true.
* @condition: the condition which the compiler should know is false.
*
* If you have some code which relies on certain constants being equal, or
* some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
* detect if someone changes it.
*
* The implementation uses gcc's reluctance to create a negative array, but gcc
* (as of 4.4) only emits that error for obvious cases (e.g. not arguments to
* inline functions). Luckily, in 4.3 they added the "error" function
* attribute just for this type of case. Thus, we use a negative sized array
* (should always create an error on gcc versions older than 4.4) and then call
* an undefined function with the error attribute (should always create an
* error on gcc 4.3 and later). If for some reason, neither creates a
* compile-time error, we'll still have a link-time error, which is harder to
* track down.
*/
#ifndef __OPTIMIZE__
#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
#else
bug.h, compiler.h: introduce compiletime_assert & BUILD_BUG_ON_MSG Introduce compiletime_assert to compiler.h, which moves the details of how to break a build and emit an error message for a specific compiler to the headers where these details should be. Following in the tradition of the POSIX assert macro, compiletime_assert creates a build-time error when the supplied condition is *false*. Next, we add BUILD_BUG_ON_MSG to bug.h which simply wraps compiletime_assert, inverting the logic, so that it fails when the condition is *true*, consistent with the language "build bug on." This macro allows you to specify the error message you want emitted when the supplied condition is true. Finally, we remove all other code from bug.h that mucks with these details (BUILD_BUG & BUILD_BUG_ON), and have them all call BUILD_BUG_ON_MSG. This not only reduces source code bloat, but also prevents the possibility of code being changed for one macro and not for the other (which was previously the case for BUILD_BUG and BUILD_BUG_ON). Since __compiletime_error_fallback is now only used in compiler.h, I'm considering it a private macro and removing the double negation that's now extraneous. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Daniel Santos <daniel.santos@pobox.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: David Rientjes <rientjes@google.com> Cc: Joe Perches <joe@perches.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-22 04:41:55 +04:00
#define BUILD_BUG_ON(condition) \
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
#endif
/**
* BUILD_BUG - break compile if used.
*
* If you have some code that you expect the compiler to eliminate at
* build time, you should use BUILD_BUG to detect if it is
* unexpectedly used.
*/
bug.h, compiler.h: introduce compiletime_assert & BUILD_BUG_ON_MSG Introduce compiletime_assert to compiler.h, which moves the details of how to break a build and emit an error message for a specific compiler to the headers where these details should be. Following in the tradition of the POSIX assert macro, compiletime_assert creates a build-time error when the supplied condition is *false*. Next, we add BUILD_BUG_ON_MSG to bug.h which simply wraps compiletime_assert, inverting the logic, so that it fails when the condition is *true*, consistent with the language "build bug on." This macro allows you to specify the error message you want emitted when the supplied condition is true. Finally, we remove all other code from bug.h that mucks with these details (BUILD_BUG & BUILD_BUG_ON), and have them all call BUILD_BUG_ON_MSG. This not only reduces source code bloat, but also prevents the possibility of code being changed for one macro and not for the other (which was previously the case for BUILD_BUG and BUILD_BUG_ON). Since __compiletime_error_fallback is now only used in compiler.h, I'm considering it a private macro and removing the double negation that's now extraneous. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Daniel Santos <daniel.santos@pobox.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: David Rientjes <rientjes@google.com> Cc: Joe Perches <joe@perches.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-22 04:41:55 +04:00
#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
#endif /* __CHECKER__ */
[PATCH] Generic BUG implementation This patch adds common handling for kernel BUGs, for use by architectures as they wish. The code is derived from arch/powerpc. The advantages of having common BUG handling are: - consistent BUG reporting across architectures - shared implementation of out-of-line file/line data - implement CONFIG_DEBUG_BUGVERBOSE consistently This means that in inline impact of BUG is just the illegal instruction itself, which is an improvement for i386 and x86-64. A BUG is represented in the instruction stream as an illegal instruction, which has file/line information associated with it. This extra information is stored in the __bug_table section in the ELF file. When the kernel gets an illegal instruction, it first confirms it might possibly be from a BUG (ie, in kernel mode, the right illegal instruction). It then calls report_bug(). This searches __bug_table for a matching instruction pointer, and if found, prints the corresponding file/line information. If report_bug() determines that it wasn't a BUG which caused the trap, it returns BUG_TRAP_TYPE_NONE. Some architectures (powerpc) implement WARN using the same mechanism; if the illegal instruction was the result of a WARN, then report_bug(Q) returns CONFIG_DEBUG_BUGVERBOSE; otherwise it returns BUG_TRAP_TYPE_BUG. lib/bug.c keeps a list of loaded modules which can be searched for __bug_table entries. The architecture must call module_bug_finalize()/module_bug_cleanup() from its corresponding module_finalize/cleanup functions. Unsetting CONFIG_DEBUG_BUGVERBOSE will reduce the kernel size by some amount. At the very least, filename and line information will not be recorded for each but, but architectures may decide to store no extra information per BUG at all. Unfortunately, gcc doesn't have a general way to mark an asm() as noreturn, so architectures will generally have to include an infinite loop (or similar) in the BUG code, so that gcc knows execution won't continue beyond that point. gcc does have a __builtin_trap() operator which may be useful to achieve the same effect, unfortunately it cannot be used to actually implement the BUG itself, because there's no way to get the instruction's address for use in generating the __bug_table entry. [randy.dunlap@oracle.com: Handle BUG=n, GENERIC_BUG=n to prevent build errors] [bunk@stusta.de: include/linux/bug.h must always #include <linux/module.h] Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Andi Kleen <ak@muc.de> Cc: Hugh Dickens <hugh@veritas.com> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 13:36:19 +03:00
#ifdef CONFIG_GENERIC_BUG
#include <asm-generic/bug.h>
static inline int is_warning_bug(const struct bug_entry *bug)
{
return bug->flags & BUGFLAG_WARNING;
}
const struct bug_entry *find_bug(unsigned long bugaddr);
enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);
[PATCH] Generic BUG implementation This patch adds common handling for kernel BUGs, for use by architectures as they wish. The code is derived from arch/powerpc. The advantages of having common BUG handling are: - consistent BUG reporting across architectures - shared implementation of out-of-line file/line data - implement CONFIG_DEBUG_BUGVERBOSE consistently This means that in inline impact of BUG is just the illegal instruction itself, which is an improvement for i386 and x86-64. A BUG is represented in the instruction stream as an illegal instruction, which has file/line information associated with it. This extra information is stored in the __bug_table section in the ELF file. When the kernel gets an illegal instruction, it first confirms it might possibly be from a BUG (ie, in kernel mode, the right illegal instruction). It then calls report_bug(). This searches __bug_table for a matching instruction pointer, and if found, prints the corresponding file/line information. If report_bug() determines that it wasn't a BUG which caused the trap, it returns BUG_TRAP_TYPE_NONE. Some architectures (powerpc) implement WARN using the same mechanism; if the illegal instruction was the result of a WARN, then report_bug(Q) returns CONFIG_DEBUG_BUGVERBOSE; otherwise it returns BUG_TRAP_TYPE_BUG. lib/bug.c keeps a list of loaded modules which can be searched for __bug_table entries. The architecture must call module_bug_finalize()/module_bug_cleanup() from its corresponding module_finalize/cleanup functions. Unsetting CONFIG_DEBUG_BUGVERBOSE will reduce the kernel size by some amount. At the very least, filename and line information will not be recorded for each but, but architectures may decide to store no extra information per BUG at all. Unfortunately, gcc doesn't have a general way to mark an asm() as noreturn, so architectures will generally have to include an infinite loop (or similar) in the BUG code, so that gcc knows execution won't continue beyond that point. gcc does have a __builtin_trap() operator which may be useful to achieve the same effect, unfortunately it cannot be used to actually implement the BUG itself, because there's no way to get the instruction's address for use in generating the __bug_table entry. [randy.dunlap@oracle.com: Handle BUG=n, GENERIC_BUG=n to prevent build errors] [bunk@stusta.de: include/linux/bug.h must always #include <linux/module.h] Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Andi Kleen <ak@muc.de> Cc: Hugh Dickens <hugh@veritas.com> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 13:36:19 +03:00
/* These are defined by the architecture */
int is_valid_bugaddr(unsigned long addr);
#else /* !CONFIG_GENERIC_BUG */
static inline enum bug_trap_type report_bug(unsigned long bug_addr,
struct pt_regs *regs)
[PATCH] Generic BUG implementation This patch adds common handling for kernel BUGs, for use by architectures as they wish. The code is derived from arch/powerpc. The advantages of having common BUG handling are: - consistent BUG reporting across architectures - shared implementation of out-of-line file/line data - implement CONFIG_DEBUG_BUGVERBOSE consistently This means that in inline impact of BUG is just the illegal instruction itself, which is an improvement for i386 and x86-64. A BUG is represented in the instruction stream as an illegal instruction, which has file/line information associated with it. This extra information is stored in the __bug_table section in the ELF file. When the kernel gets an illegal instruction, it first confirms it might possibly be from a BUG (ie, in kernel mode, the right illegal instruction). It then calls report_bug(). This searches __bug_table for a matching instruction pointer, and if found, prints the corresponding file/line information. If report_bug() determines that it wasn't a BUG which caused the trap, it returns BUG_TRAP_TYPE_NONE. Some architectures (powerpc) implement WARN using the same mechanism; if the illegal instruction was the result of a WARN, then report_bug(Q) returns CONFIG_DEBUG_BUGVERBOSE; otherwise it returns BUG_TRAP_TYPE_BUG. lib/bug.c keeps a list of loaded modules which can be searched for __bug_table entries. The architecture must call module_bug_finalize()/module_bug_cleanup() from its corresponding module_finalize/cleanup functions. Unsetting CONFIG_DEBUG_BUGVERBOSE will reduce the kernel size by some amount. At the very least, filename and line information will not be recorded for each but, but architectures may decide to store no extra information per BUG at all. Unfortunately, gcc doesn't have a general way to mark an asm() as noreturn, so architectures will generally have to include an infinite loop (or similar) in the BUG code, so that gcc knows execution won't continue beyond that point. gcc does have a __builtin_trap() operator which may be useful to achieve the same effect, unfortunately it cannot be used to actually implement the BUG itself, because there's no way to get the instruction's address for use in generating the __bug_table entry. [randy.dunlap@oracle.com: Handle BUG=n, GENERIC_BUG=n to prevent build errors] [bunk@stusta.de: include/linux/bug.h must always #include <linux/module.h] Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Andi Kleen <ak@muc.de> Cc: Hugh Dickens <hugh@veritas.com> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 13:36:19 +03:00
{
return BUG_TRAP_TYPE_BUG;
}
#endif /* CONFIG_GENERIC_BUG */
#endif /* _LINUX_BUG_H */