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![Yehuda Sadeh](/assets/img/avatar_default.png)
We should initialize the module dynamic debug datastructures only after determining that the module is not loaded yet. This fixes a bug that introduced in 2.6.35-rc2, where when a trying to load a module twice, we also load it's dynamic printing data twice which causes all sorts of nasty issues. Also handle the dynamic debug cleanup later on failure. Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed a #ifdef) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
87 lines
2.7 KiB
C
87 lines
2.7 KiB
C
#ifndef _DYNAMIC_DEBUG_H
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#define _DYNAMIC_DEBUG_H
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/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
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* bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
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* use independent hash functions, to reduce the chance of false positives.
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*/
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extern long long dynamic_debug_enabled;
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extern long long dynamic_debug_enabled2;
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/*
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* An instance of this structure is created in a special
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* ELF section at every dynamic debug callsite. At runtime,
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* the special section is treated as an array of these.
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*/
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struct _ddebug {
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/*
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* These fields are used to drive the user interface
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* for selecting and displaying debug callsites.
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*/
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const char *modname;
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const char *function;
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const char *filename;
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const char *format;
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char primary_hash;
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char secondary_hash;
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unsigned int lineno:24;
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/*
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* The flags field controls the behaviour at the callsite.
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* The bits here are changed dynamically when the user
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* writes commands to <debugfs>/dynamic_debug/control
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*/
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#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */
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#define _DPRINTK_FLAGS_DEFAULT 0
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unsigned int flags:8;
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} __attribute__((aligned(8)));
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int ddebug_add_module(struct _ddebug *tab, unsigned int n,
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const char *modname);
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#if defined(CONFIG_DYNAMIC_DEBUG)
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extern int ddebug_remove_module(const char *mod_name);
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#define __dynamic_dbg_enabled(dd) ({ \
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int __ret = 0; \
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if (unlikely((dynamic_debug_enabled & (1LL << DEBUG_HASH)) && \
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(dynamic_debug_enabled2 & (1LL << DEBUG_HASH2)))) \
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if (unlikely(dd.flags)) \
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__ret = 1; \
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__ret; })
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#define dynamic_pr_debug(fmt, ...) do { \
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static struct _ddebug descriptor \
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__used \
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__attribute__((section("__verbose"), aligned(8))) = \
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{ KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \
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DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \
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if (__dynamic_dbg_enabled(descriptor)) \
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printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
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} while (0)
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#define dynamic_dev_dbg(dev, fmt, ...) do { \
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static struct _ddebug descriptor \
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__used \
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__attribute__((section("__verbose"), aligned(8))) = \
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{ KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \
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DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \
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if (__dynamic_dbg_enabled(descriptor)) \
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dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \
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} while (0)
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#else
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static inline int ddebug_remove_module(const char *mod)
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{
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return 0;
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}
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#define dynamic_pr_debug(fmt, ...) \
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do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
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#define dynamic_dev_dbg(dev, format, ...) \
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do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
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#endif
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#endif
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