/* * lib/dynamic_debug.c * * make pr_debug()/dev_dbg() calls runtime configurable based upon their * source module. * * Copyright (C) 2008 Jason Baron <jbaron@redhat.com> * By Greg Banks <gnb@melbourne.sgi.com> * Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved. * Copyright (C) 2011 Bart Van Assche. All Rights Reserved. * Copyright (C) 2013 Du, Changbin <changbin.du@gmail.com> */ #define pr_fmt(fmt) "dyndbg: " fmt #include <linux/kernel.h>#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/kallsyms.h>#include <linux/types.h>#include <linux/mutex.h>#include <linux/proc_fs.h>#include <linux/seq_file.h>#include <linux/list.h>#include <linux/sysctl.h>#include <linux/ctype.h>#include <linux/string.h>#include <linux/parser.h>#include <linux/string_helpers.h>#include <linux/uaccess.h>#include <linux/dynamic_debug.h>#include <linux/debugfs.h>#include <linux/slab.h>#include <linux/jump_label.h>#include <linux/hardirq.h>#include <linux/sched.h>#include <linux/device.h>#include <linux/netdevice.h> #include <rdma/ib_verbs.h> extern struct _ddebug __start___dyndbg[];extern struct _ddebug __stop___dyndbg[]; struct ddebug_table { struct list_head link; const char *mod_name; unsigned int num_ddebugs; struct _ddebug *ddebugs;}; struct ddebug_query { const char *filename; const char *module; const char *function; const char *format; unsigned int first_lineno, last_lineno;}; struct ddebug_iter { struct ddebug_table *table; unsigned int idx;}; struct flag_settings { unsigned int flags; unsigned int mask;}; static DEFINE_MUTEX(ddebug_lock);static LIST_HEAD(ddebug_tables);static int verbose;module_param(verbose, int, 0644); /* Return the path relative to source root */static inline const char *trim_prefix(const char *path){ int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c"); if (strncmp(path, __FILE__, skip)) skip = 0; /* prefix mismatch, don't skip */ return path + skip;} static struct { unsigned flag:8; char opt_char; } opt_array[] = { { _DPRINTK_FLAGS_PRINT, 'p' }, { _DPRINTK_FLAGS_INCL_MODNAME, 'm' }, { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' }, { _DPRINTK_FLAGS_INCL_LINENO, 'l' }, { _DPRINTK_FLAGS_INCL_TID, 't' }, { _DPRINTK_FLAGS_NONE, '_' },}; struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; }; /* format a string into buf[] which describes the _ddebug's flags */static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb){ char *p = fb->buf; int i; for (i = 0; i < ARRAY_SIZE(opt_array); ++i) if (flags & opt_array[i].flag) *p++ = opt_array[i].opt_char; if (p == fb->buf) *p++ = '_'; *p = '\0'; return fb->buf;} #define vnpr_info(lvl, fmt, ...) \do { \ if (verbose >= lvl) \ pr_info(fmt, ##__VA_ARGS__); \} while (0) #define vpr_info(fmt, ...) vnpr_info(1, fmt, ##__VA_ARGS__)#define v2pr_info(fmt, ...) vnpr_info(2, fmt, ##__VA_ARGS__) static void vpr_info_dq(const struct ddebug_query *query, const char *msg){ /* trim any trailing newlines */ int fmtlen = 0; if (query->format) { fmtlen = strlen(query->format); while (fmtlen && query->format[fmtlen - 1] == '\n') fmtlen--; } vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n", msg, query->function ?: "", query->filename ?: "", query->module ?: "", fmtlen, query->format ?: "", query->first_lineno, query->last_lineno);} /* * Search the tables for _ddebug's which match the given `query' and * apply the `flags' and `mask' to them. Returns number of matching * callsites, normally the same as number of changes. If verbose, * logs the changes. Takes ddebug_lock. */static int ddebug_change(const struct ddebug_query *query, struct flag_settings *modifiers){ int i; struct ddebug_table *dt; unsigned int newflags; unsigned int nfound = 0; struct flagsbuf fbuf; /* search for matching ddebugs */ mutex_lock(&ddebug_lock); list_for_each_entry(dt, &ddebug_tables, link) { /* match against the module name */ if (query->module && !match_wildcard(query->module, dt->mod_name)) continue; for (i = 0; i < dt->num_ddebugs; i++) { struct _ddebug *dp = &dt->ddebugs[i]; /* match against the source filename */ if (query->filename && !match_wildcard(query->filename, dp->filename) && !match_wildcard(query->filename, kbasename(dp->filename)) && !match_wildcard(query->filename, trim_prefix(dp->filename))) continue; /* match against the function */ if (query->function && !match_wildcard(query->function, dp->function)) continue; /* match against the format */ if (query->format) { if (*query->format == '^') { char *p; /* anchored search. match must be at beginning */ p = strstr(dp->format, query->format+1); if (p != dp->format) continue; } else if (!strstr(dp->format, query->format)) continue; } /* match against the line number range */ if (query->first_lineno && dp->lineno < query->first_lineno) continue; if (query->last_lineno && dp->lineno > query->last_lineno) continue; nfound++; newflags = (dp->flags & modifiers->mask) | modifiers->flags; if (newflags == dp->flags) continue;#ifdef CONFIG_JUMP_LABEL if (dp->flags & _DPRINTK_FLAGS_PRINT) { if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT)) static_branch_disable(&dp->key.dd_key_true); } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT) static_branch_enable(&dp->key.dd_key_true);#endif dp->flags = newflags; v2pr_info("changed %s:%d [%s]%s =%s\n", trim_prefix(dp->filename), dp->lineno, dt->mod_name, dp->function, ddebug_describe_flags(dp->flags, &fbuf)); } } mutex_unlock(&ddebug_lock); if (!nfound && verbose) pr_info("no matches for query\n"); return nfound;} /* * Split the buffer `buf' into space-separated words. * Handles simple " and ' quoting, i.e. without nested, * embedded or escaped \". Return the number of words * or <0 on error. */static int ddebug_tokenize(char *buf, char *words[], int maxwords){ int nwords = 0; while (*buf) { char *end; /* Skip leading whitespace */ buf = skip_spaces(buf); if (!*buf) break; /* oh, it was trailing whitespace */ if (*buf == '#') break; /* token starts comment, skip rest of line */ /* find `end' of word, whitespace separated or quoted */ if (*buf == '"' || *buf == '\'') { int quote = *buf++; for (end = buf; *end && *end != quote; end++) ; if (!*end) { pr_err("unclosed quote: %s\n", buf); return -EINVAL; /* unclosed quote */ } } else { for (end = buf; *end && !isspace(*end); end++) ; BUG_ON(end == buf); } /* `buf' is start of word, `end' is one past its end */ if (nwords == maxwords) { pr_err("too many words, legal max <=%d\n", maxwords); return -EINVAL; /* ran out of words[] before bytes */ } if (*end) *end++ = '\0'; /* terminate the word */ words[nwords++] = buf; buf = end; } if (verbose) { int i; pr_info("split into words:"); for (i = 0; i < nwords; i++) pr_cont(" \"%s\"", words[i]); pr_cont("\n"); } return nwords;} /* * Parse a single line number. Note that the empty string "" * is treated as a special case and converted to zero, which * is later treated as a "don't care" value. */static inline int parse_lineno(const char *str, unsigned int *val){ BUG_ON(str == NULL); if (*str == '\0') { *val = 0; return 0; } if (kstrtouint(str, 10, val) < 0) { pr_err("bad line-number: %s\n", str); return -EINVAL; } return 0;} static int parse_linerange(struct ddebug_query *query, const char *first){ char *last = strchr(first, '-'); if (query->first_lineno || query->last_lineno) { pr_err("match-spec: line used 2x\n"); return -EINVAL; } if (last) *last++ = '\0'; if (parse_lineno(first, &query->first_lineno) < 0) return -EINVAL; if (last) { /* range <first>-<last> */ if (parse_lineno(last, &query->last_lineno) < 0) return -EINVAL; /* special case for last lineno not specified */ if (query->last_lineno == 0) query->last_lineno = UINT_MAX; if (query->last_lineno < query->first_lineno) { pr_err("last-line:%d < 1st-line:%d\n", query->last_lineno, query->first_lineno); return -EINVAL; } } else { query->last_lineno = query->first_lineno; } vpr_info("parsed line %d-%d\n", query->first_lineno, query->last_lineno); return 0;} static int check_set(const char **dest, char *src, char *name){ int rc = 0; if (*dest) { rc = -EINVAL; pr_err("match-spec:%s val:%s overridden by %s\n", name, *dest, src); } *dest = src; return rc;} /* * Parse words[] as a ddebug query specification, which is a series * of (keyword, value) pairs chosen from these possibilities: * * func <function-name> * file <full-pathname> * file <base-filename> * module <module-name> * format <escaped-string-to-find-in-format> * line <lineno> * line <first-lineno>-<last-lineno> // where either may be empty * * Only 1 of each type is allowed. * Returns 0 on success, <0 on error. */static int ddebug_parse_query(char *words[], int nwords, struct ddebug_query *query, const char *modname){ unsigned int i; int rc = 0; char *fline; /* check we have an even number of words */ if (nwords % 2 != 0) { pr_err("expecting pairs of match-spec <value>\n"); return -EINVAL; } if (modname) /* support $modname.dyndbg=<multiple queries> */ query->module = modname; for (i = 0; i < nwords; i += 2) { char *keyword = words[i]; char *arg = words[i+1]; if (!strcmp(keyword, "func")) { rc = check_set(&query->function, arg, "func"); } else if (!strcmp(keyword, "file")) { if (check_set(&query->filename, arg, "file")) return -EINVAL; /* tail :$info is function or line-range */ fline = strchr(query->filename, ':'); if (!fline) break; *fline++ = '\0'; if (isalpha(*fline) || *fline == '*' || *fline == '?') { /* take as function name */ if (check_set(&query->function, fline, "func")) return -EINVAL; } else { if (parse_linerange(query, fline)) return -EINVAL; } } else if (!strcmp(keyword, "module")) { rc = check_set(&query->module, arg, "module"); } else if (!strcmp(keyword, "format")) { string_unescape_inplace(arg, UNESCAPE_SPACE | UNESCAPE_OCTAL | UNESCAPE_SPECIAL); rc = check_set(&query->format, arg, "format"); } else if (!strcmp(keyword, "line")) { if (parse_linerange(query, arg)) return -EINVAL; } else { pr_err("unknown keyword \"%s\"\n", keyword); return -EINVAL; } if (rc) return rc; } vpr_info_dq(query, "parsed"); return 0;} /* * Parse `str' as a flags specification, format [-+=][p]+. * Sets up *maskp and *flagsp to be used when changing the * flags fields of matched _ddebug's. Returns 0 on success * or <0 on error. */static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers){ int op, i; switch (*str) { case '+': case '-': case '=': op = *str++; break; default: pr_err("bad flag-op %c, at start of %s\n", *str, str); return -EINVAL; } vpr_info("op='%c'\n", op); for (; *str ; ++str) { for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) { if (*str == opt_array[i].opt_char) { modifiers->flags |= opt_array[i].flag; break; } } if (i < 0) { pr_err("unknown flag '%c'\n", *str); return -EINVAL; } } vpr_info("flags=0x%x\n", modifiers->flags); /* calculate final flags, mask based upon op */ switch (op) { case '=': /* modifiers->flags already set */ modifiers->mask = 0; break; case '+': modifiers->mask = ~0U; break; case '-': modifiers->mask = ~modifiers->flags; modifiers->flags = 0; break; } vpr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask); return 0;} static int ddebug_exec_query(char *query_string, const char *modname){ struct flag_settings modifiers = {}; struct ddebug_query query = {};#define MAXWORDS 9 int nwords, nfound; char *words[MAXWORDS]; nwords = ddebug_tokenize(query_string, words, MAXWORDS); if (nwords <= 0) { pr_err("tokenize failed\n"); return -EINVAL; } /* check flags 1st (last arg) so query is pairs of spec,val */ if (ddebug_parse_flags(words[nwords-1], &modifiers)) { pr_err("flags parse failed\n");Lines 1–500 of 1152. 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/* * lib/dynamic_debug.c * * make pr_debug()/dev_dbg() calls runtime configurable based upon their * source module. * * Copyright (C) 2008 Jason Baron <jbaron@redhat.com> * By Greg Banks <gnb@melbourne.sgi.com> * Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved. * Copyright (C) 2011 Bart Van Assche. All Rights Reserved. * Copyright (C) 2013 Du, Changbin <changbin.du@gmail.com> */ #define pr_fmt(fmt) "dyndbg: " fmt #include <linux/kernel.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/kallsyms.h> #include <linux/types.h> #include <linux/mutex.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/list.h> #include <linux/sysctl.h> #include <linux/ctype.h> #include <linux/string.h> #include <linux/parser.h> #include <linux/string_helpers.h> #include <linux/uaccess.h> #include <linux/dynamic_debug.h> #include <linux/debugfs.h> #include <linux/slab.h> #include <linux/jump_label.h> #include <linux/hardirq.h> #include <linux/sched.h> #include <linux/device.h> #include <linux/netdevice.h> #include <rdma/ib_verbs.h> extern struct _ddebug __start___dyndbg[]; extern struct _ddebug __stop___dyndbg[]; struct ddebug_table { struct list_head link; const char *mod_name; unsigned int num_ddebugs; struct _ddebug *ddebugs; }; struct ddebug_query { const char *filename; const char *module; const char *function; const char *format; unsigned int first_lineno, last_lineno; }; struct ddebug_iter { struct ddebug_table *table; unsigned int idx; }; struct flag_settings { unsigned int flags; unsigned int mask; }; static DEFINE_MUTEX(ddebug_lock); static LIST_HEAD(ddebug_tables); static int verbose; module_param(verbose, int, 0644); /* Return the path relative to source root */ static inline const char *trim_prefix(const char *path) { int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c"); if (strncmp(path, __FILE__, skip)) skip = 0; /* prefix mismatch, don't skip */ return path + skip; } static struct { unsigned flag:8; char opt_char; } opt_array[] = { { _DPRINTK_FLAGS_PRINT, 'p' }, { _DPRINTK_FLAGS_INCL_MODNAME, 'm' }, { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' }, { _DPRINTK_FLAGS_INCL_LINENO, 'l' }, { _DPRINTK_FLAGS_INCL_TID, 't' }, { _DPRINTK_FLAGS_NONE, '_' }, }; struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; }; /* format a string into buf[] which describes the _ddebug's flags */ static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb) { char *p = fb->buf; int i; for (i = 0; i < ARRAY_SIZE(opt_array); ++i) if (flags & opt_array[i].flag) *p++ = opt_array[i].opt_char; if (p == fb->buf) *p++ = '_'; *p = '\0'; return fb->buf; } #define vnpr_info(lvl, fmt, ...) \ do { \ if (verbose >= lvl) \ pr_info(fmt, ##__VA_ARGS__); \ } while (0) #define vpr_info(fmt, ...) vnpr_info(1, fmt, ##__VA_ARGS__) #define v2pr_info(fmt, ...) vnpr_info(2, fmt, ##__VA_ARGS__) static void vpr_info_dq(const struct ddebug_query *query, const char *msg) { /* trim any trailing newlines */ int fmtlen = 0; if (query->format) { fmtlen = strlen(query->format); while (fmtlen && query->format[fmtlen - 1] == '\n') fmtlen--; } vpr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n", msg, query->function ?: "", query->filename ?: "", query->module ?: "", fmtlen, query->format ?: "", query->first_lineno, query->last_lineno); } /* * Search the tables for _ddebug's which match the given `query' and * apply the `flags' and `mask' to them. Returns number of matching * callsites, normally the same as number of changes. If verbose, * logs the changes. Takes ddebug_lock. */ static int ddebug_change(const struct ddebug_query *query, struct flag_settings *modifiers) { int i; struct ddebug_table *dt; unsigned int newflags; unsigned int nfound = 0; struct flagsbuf fbuf; /* search for matching ddebugs */ mutex_lock(&ddebug_lock); list_for_each_entry(dt, &ddebug_tables, link) { /* match against the module name */ if (query->module && !match_wildcard(query->module, dt->mod_name)) continue; for (i = 0; i < dt->num_ddebugs; i++) { struct _ddebug *dp = &dt->ddebugs[i]; /* match against the source filename */ if (query->filename && !match_wildcard(query->filename, dp->filename) && !match_wildcard(query->filename, kbasename(dp->filename)) && !match_wildcard(query->filename, trim_prefix(dp->filename))) continue; /* match against the function */ if (query->function && !match_wildcard(query->function, dp->function)) continue; /* match against the format */ if (query->format) { if (*query->format == '^') { char *p; /* anchored search. match must be at beginning */ p = strstr(dp->format, query->format+1); if (p != dp->format) continue; } else if (!strstr(dp->format, query->format)) continue; } /* match against the line number range */ if (query->first_lineno && dp->lineno < query->first_lineno) continue; if (query->last_lineno && dp->lineno > query->last_lineno) continue; nfound++; newflags = (dp->flags & modifiers->mask) | modifiers->flags; if (newflags == dp->flags) continue; #ifdef CONFIG_JUMP_LABEL if (dp->flags & _DPRINTK_FLAGS_PRINT) { if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT)) static_branch_disable(&dp->key.dd_key_true); } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT) static_branch_enable(&dp->key.dd_key_true); #endif dp->flags = newflags; v2pr_info("changed %s:%d [%s]%s =%s\n", trim_prefix(dp->filename), dp->lineno, dt->mod_name, dp->function, ddebug_describe_flags(dp->flags, &fbuf)); } } mutex_unlock(&ddebug_lock); if (!nfound && verbose) pr_info("no matches for query\n"); return nfound; } /* * Split the buffer `buf' into space-separated words. * Handles simple " and ' quoting, i.e. without nested, * embedded or escaped \". Return the number of words * or <0 on error. */ static int ddebug_tokenize(char *buf, char *words[], int maxwords) { int nwords = 0; while (*buf) { char *end; /* Skip leading whitespace */ buf = skip_spaces(buf); if (!*buf) break; /* oh, it was trailing whitespace */ if (*buf == '#') break; /* token starts comment, skip rest of line */ /* find `end' of word, whitespace separated or quoted */ if (*buf == '"' || *buf == '\'') { int quote = *buf++; for (end = buf; *end && *end != quote; end++) ; if (!*end) { pr_err("unclosed quote: %s\n", buf); return -EINVAL; /* unclosed quote */ } } else { for (end = buf; *end && !isspace(*end); end++) ; BUG_ON(end == buf); } /* `buf' is start of word, `end' is one past its end */ if (nwords == maxwords) { pr_err("too many words, legal max <=%d\n", maxwords); return -EINVAL; /* ran out of words[] before bytes */ } if (*end) *end++ = '\0'; /* terminate the word */ words[nwords++] = buf; buf = end; } if (verbose) { int i; pr_info("split into words:"); for (i = 0; i < nwords; i++) pr_cont(" \"%s\"", words[i]); pr_cont("\n"); } return nwords; } /* * Parse a single line number. Note that the empty string "" * is treated as a special case and converted to zero, which * is later treated as a "don't care" value. */ static inline int parse_lineno(const char *str, unsigned int *val) { BUG_ON(str == NULL); if (*str == '\0') { *val = 0; return 0; } if (kstrtouint(str, 10, val) < 0) { pr_err("bad line-number: %s\n", str); return -EINVAL; } return 0; } static int parse_linerange(struct ddebug_query *query, const char *first) { char *last = strchr(first, '-'); if (query->first_lineno || query->last_lineno) { pr_err("match-spec: line used 2x\n"); return -EINVAL; } if (last) *last++ = '\0'; if (parse_lineno(first, &query->first_lineno) < 0) return -EINVAL; if (last) { /* range <first>-<last> */ if (parse_lineno(last, &query->last_lineno) < 0) return -EINVAL; /* special case for last lineno not specified */ if (query->last_lineno == 0) query->last_lineno = UINT_MAX; if (query->last_lineno < query->first_lineno) { pr_err("last-line:%d < 1st-line:%d\n", query->last_lineno, query->first_lineno); return -EINVAL; } } else { query->last_lineno = query->first_lineno; } vpr_info("parsed line %d-%d\n", query->first_lineno, query->last_lineno); return 0; } static int check_set(const char **dest, char *src, char *name) { int rc = 0; if (*dest) { rc = -EINVAL; pr_err("match-spec:%s val:%s overridden by %s\n", name, *dest, src); } *dest = src; return rc; } /* * Parse words[] as a ddebug query specification, which is a series * of (keyword, value) pairs chosen from these possibilities: * * func <function-name> * file <full-pathname> * file <base-filename> * module <module-name> * format <escaped-string-to-find-in-format> * line <lineno> * line <first-lineno>-<last-lineno> // where either may be empty * * Only 1 of each type is allowed. * Returns 0 on success, <0 on error. */ static int ddebug_parse_query(char *words[], int nwords, struct ddebug_query *query, const char *modname) { unsigned int i; int rc = 0; char *fline; /* check we have an even number of words */ if (nwords % 2 != 0) { pr_err("expecting pairs of match-spec <value>\n"); return -EINVAL; } if (modname) /* support $modname.dyndbg=<multiple queries> */ query->module = modname; for (i = 0; i < nwords; i += 2) { char *keyword = words[i]; char *arg = words[i+1]; if (!strcmp(keyword, "func")) { rc = check_set(&query->function, arg, "func"); } else if (!strcmp(keyword, "file")) { if (check_set(&query->filename, arg, "file")) return -EINVAL; /* tail :$info is function or line-range */ fline = strchr(query->filename, ':'); if (!fline) break; *fline++ = '\0'; if (isalpha(*fline) || *fline == '*' || *fline == '?') { /* take as function name */ if (check_set(&query->function, fline, "func")) return -EINVAL; } else { if (parse_linerange(query, fline)) return -EINVAL; } } else if (!strcmp(keyword, "module")) { rc = check_set(&query->module, arg, "module"); } else if (!strcmp(keyword, "format")) { string_unescape_inplace(arg, UNESCAPE_SPACE | UNESCAPE_OCTAL | UNESCAPE_SPECIAL); rc = check_set(&query->format, arg, "format"); } else if (!strcmp(keyword, "line")) { if (parse_linerange(query, arg)) return -EINVAL; } else { pr_err("unknown keyword \"%s\"\n", keyword); return -EINVAL; } if (rc) return rc; } vpr_info_dq(query, "parsed"); return 0; } /* * Parse `str' as a flags specification, format [-+=][p]+. * Sets up *maskp and *flagsp to be used when changing the * flags fields of matched _ddebug's. Returns 0 on success * or <0 on error. */ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers) { int op, i; switch (*str) { case '+': case '-': case '=': op = *str++; break; default: pr_err("bad flag-op %c, at start of %s\n", *str, str); return -EINVAL; } vpr_info("op='%c'\n", op); for (; *str ; ++str) { for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) { if (*str == opt_array[i].opt_char) { modifiers->flags |= opt_array[i].flag; break; } } if (i < 0) { pr_err("unknown flag '%c'\n", *str); return -EINVAL; } } vpr_info("flags=0x%x\n", modifiers->flags); /* calculate final flags, mask based upon op */ switch (op) { case '=': /* modifiers->flags already set */ modifiers->mask = 0; break; case '+': modifiers->mask = ~0U; break; case '-': modifiers->mask = ~modifiers->flags; modifiers->flags = 0; break; } vpr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask); return 0; } static int ddebug_exec_query(char *query_string, const char *modname) { struct flag_settings modifiers = {}; struct ddebug_query query = {}; #define MAXWORDS 9 int nwords, nfound; char *words[MAXWORDS]; nwords = ddebug_tokenize(query_string, words, MAXWORDS); if (nwords <= 0) { pr_err("tokenize failed\n"); return -EINVAL; } /* check flags 1st (last arg) so query is pairs of spec,val */ if (ddebug_parse_flags(words[nwords-1], &modifiers)) { pr_err("flags parse failed\n");