// SPDX-License-Identifier: GPL-2.0/* * S/390 debug facility * * Copyright IBM Corp. 1999, 2020 * * Author(s): Michael Holzheu (holzheu@de.ibm.com), * Holger Smolinski (Holger.Smolinski@de.ibm.com) * * Bugreports to: <Linux390@de.ibm.com> */ #define KMSG_COMPONENT "s390dbf"#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include <linux/stddef.h>#include <linux/kernel.h>#include <linux/errno.h>#include <linux/slab.h>#include <linux/ctype.h>#include <linux/string.h>#include <linux/sysctl.h>#include <linux/uaccess.h>#include <linux/export.h>#include <linux/init.h>#include <linux/fs.h>#include <linux/minmax.h>#include <linux/debugfs.h> #include <asm/debug.h> #define DEBUG_PROLOG_ENTRY -1 #define ALL_AREAS 0 /* copy all debug areas */#define NO_AREAS 1 /* copy no debug areas */ /* typedefs */ typedef struct file_private_info { loff_t offset; /* offset of last read in file */ int act_area; /* number of last formatted area */ int act_page; /* act page in given area */ int act_entry; /* last formatted entry (offset */ /* relative to beginning of last */ /* formatted page) */ size_t act_entry_offset; /* up to this offset we copied */ /* in last read the last formatted */ /* entry to userland */ char temp_buf[2048]; /* buffer for output */ debug_info_t *debug_info_org; /* original debug information */ debug_info_t *debug_info_snap; /* snapshot of debug information */ struct debug_view *view; /* used view of debug info */} file_private_info_t; typedef struct { char *string; /* * This assumes that all args are converted into longs * on L/390 this is the case for all types of parameter * except of floats, and long long (32 bit) * */ long args[];} debug_sprintf_entry_t; /* internal function prototypes */ static int debug_init(void);static ssize_t debug_output(struct file *file, char __user *user_buf, size_t user_len, loff_t *offset);static ssize_t debug_input(struct file *file, const char __user *user_buf, size_t user_len, loff_t *offset);static int debug_open(struct inode *inode, struct file *file);static int debug_close(struct inode *inode, struct file *file);static debug_info_t *debug_info_create(const char *name, int pages_per_area, int nr_areas, int buf_size, umode_t mode);static void debug_info_get(debug_info_t *);static void debug_info_put(debug_info_t *);static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view, char *out_buf, size_t out_buf_size);static int debug_input_level_fn(debug_info_t *id, struct debug_view *view, struct file *file, const char __user *user_buf, size_t user_buf_size, loff_t *offset);static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view, char *out_buf, size_t out_buf_size);static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view, struct file *file, const char __user *user_buf, size_t user_buf_size, loff_t *offset);static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view, struct file *file, const char __user *user_buf, size_t user_buf_size, loff_t *offset);static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view, char *out_buf, size_t out_buf_size, const char *in_buf);static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view, char *out_buf, size_t out_buf_size, const char *inbuf);static void debug_areas_swap(debug_info_t *a, debug_info_t *b);static void debug_events_append(debug_info_t *dest, debug_info_t *src); /* globals */ struct debug_view debug_hex_ascii_view = { "hex_ascii", NULL, &debug_dflt_header_fn, &debug_hex_ascii_format_fn, NULL, NULL};EXPORT_SYMBOL(debug_hex_ascii_view); static struct debug_view debug_level_view = { "level", &debug_prolog_level_fn, NULL, NULL, &debug_input_level_fn, NULL}; static struct debug_view debug_pages_view = { "pages", &debug_prolog_pages_fn, NULL, NULL, &debug_input_pages_fn, NULL}; static struct debug_view debug_flush_view = { "flush", NULL, NULL, NULL, &debug_input_flush_fn, NULL}; struct debug_view debug_sprintf_view = { "sprintf", NULL, &debug_dflt_header_fn, &debug_sprintf_format_fn, NULL, NULL};EXPORT_SYMBOL(debug_sprintf_view); /* used by dump analysis tools to determine version of debug feature */static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; /* static globals */ static debug_info_t *debug_area_first;static debug_info_t *debug_area_last;static DEFINE_MUTEX(debug_mutex); static int initialized;static int debug_critical; static const struct file_operations debug_file_ops = { .owner = THIS_MODULE, .read = debug_output, .write = debug_input, .open = debug_open, .release = debug_close,}; static struct dentry *debug_debugfs_root_entry; /* functions */ /* * debug_areas_alloc * - Debug areas are implemented as a threedimensonal array: * areas[areanumber][pagenumber][pageoffset] */ static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas){ debug_entry_t ***areas; int i, j; areas = kmalloc_array(nr_areas, sizeof(debug_entry_t **), GFP_KERNEL); if (!areas) goto fail_malloc_areas; for (i = 0; i < nr_areas; i++) { /* GFP_NOWARN to avoid user triggerable WARN, we handle fails */ areas[i] = kmalloc_array(pages_per_area, sizeof(debug_entry_t *), GFP_KERNEL | __GFP_NOWARN); if (!areas[i]) goto fail_malloc_areas2; for (j = 0; j < pages_per_area; j++) { areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL); if (!areas[i][j]) { for (j--; j >= 0 ; j--) kfree(areas[i][j]); kfree(areas[i]); goto fail_malloc_areas2; } } } return areas; fail_malloc_areas2: for (i--; i >= 0; i--) { for (j = 0; j < pages_per_area; j++) kfree(areas[i][j]); kfree(areas[i]); } kfree(areas);fail_malloc_areas: return NULL;} /* * debug_info_alloc * - alloc new debug-info */static debug_info_t *debug_info_alloc(const char *name, int pages_per_area, int nr_areas, int buf_size, int level, int mode){ debug_info_t *rc; /* alloc everything */ rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL); if (!rc) goto fail_malloc_rc; rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); if (!rc->active_entries) goto fail_malloc_active_entries; rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); if (!rc->active_pages) goto fail_malloc_active_pages; if ((mode == ALL_AREAS) && (pages_per_area != 0)) { rc->areas = debug_areas_alloc(pages_per_area, nr_areas); if (!rc->areas) goto fail_malloc_areas; } else { rc->areas = NULL; } /* initialize members */ spin_lock_init(&rc->lock); rc->pages_per_area = pages_per_area; rc->nr_areas = nr_areas; rc->active_area = 0; rc->level = level; rc->buf_size = buf_size; rc->entry_size = sizeof(debug_entry_t) + buf_size; strscpy(rc->name, name, sizeof(rc->name)); memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *)); memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *)); refcount_set(&(rc->ref_count), 0); return rc; fail_malloc_areas: kfree(rc->active_pages);fail_malloc_active_pages: kfree(rc->active_entries);fail_malloc_active_entries: kfree(rc);fail_malloc_rc: return NULL;} /* * debug_areas_free * - free all debug areas */static void debug_areas_free(debug_info_t *db_info){ int i, j; if (!db_info->areas) return; for (i = 0; i < db_info->nr_areas; i++) { for (j = 0; j < db_info->pages_per_area; j++) kfree(db_info->areas[i][j]); kfree(db_info->areas[i]); } kfree(db_info->areas); db_info->areas = NULL;} /* * debug_info_free * - free memory debug-info */static void debug_info_free(debug_info_t *db_info){ debug_areas_free(db_info); kfree(db_info->active_entries); kfree(db_info->active_pages); kfree(db_info);} /* * debug_info_create * - create new debug-info */ static debug_info_t *debug_info_create(const char *name, int pages_per_area, int nr_areas, int buf_size, umode_t mode){ debug_info_t *rc; rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size, DEBUG_DEFAULT_LEVEL, ALL_AREAS); if (!rc) goto out; rc->mode = mode & ~S_IFMT; refcount_set(&rc->ref_count, 1);out: return rc;} /* * debug_info_copy * - copy debug-info */static debug_info_t *debug_info_copy(debug_info_t *in, int mode){ unsigned long flags; debug_info_t *rc; int i, j; /* get a consistent copy of the debug areas */ do { rc = debug_info_alloc(in->name, in->pages_per_area, in->nr_areas, in->buf_size, in->level, mode); spin_lock_irqsave(&in->lock, flags); if (!rc) goto out; /* has something changed in the meantime ? */ if ((rc->pages_per_area == in->pages_per_area) && (rc->nr_areas == in->nr_areas)) { break; } spin_unlock_irqrestore(&in->lock, flags); debug_info_free(rc); } while (1); if (mode == NO_AREAS) goto out; for (i = 0; i < in->nr_areas; i++) { for (j = 0; j < in->pages_per_area; j++) memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE); }out: spin_unlock_irqrestore(&in->lock, flags); return rc;} /* * debug_info_get * - increments reference count for debug-info */static void debug_info_get(debug_info_t *db_info){ if (db_info) refcount_inc(&db_info->ref_count);} /* * debug_info_put: * - decreases reference count for debug-info and frees it if necessary */static void debug_info_put(debug_info_t *db_info){ if (!db_info) return; if (refcount_dec_and_test(&db_info->ref_count)) debug_info_free(db_info);} /* * debug_format_entry: * - format one debug entry and return size of formatted data */static int debug_format_entry(file_private_info_t *p_info){ debug_info_t *id_snap = p_info->debug_info_snap; struct debug_view *view = p_info->view; debug_entry_t *act_entry; size_t len = 0; if (p_info->act_entry == DEBUG_PROLOG_ENTRY) { /* print prolog */ if (view->prolog_proc) { len += view->prolog_proc(id_snap, view, p_info->temp_buf, sizeof(p_info->temp_buf)); } goto out; } if (!id_snap->areas) /* this is true, if we have a prolog only view */ goto out; /* or if 'pages_per_area' is 0 */ act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area] [p_info->act_page] + p_info->act_entry); if (act_entry->clock == 0LL) goto out; /* empty entry */ if (view->header_proc) { len += view->header_proc(id_snap, view, p_info->act_area, act_entry, p_info->temp_buf + len, sizeof(p_info->temp_buf) - len); } if (view->format_proc) { len += view->format_proc(id_snap, view, p_info->temp_buf + len, sizeof(p_info->temp_buf) - len, DEBUG_DATA(act_entry)); }out: return len;} /* * debug_next_entry: * - goto next entry in p_info */static inline int debug_next_entry(file_private_info_t *p_info){ debug_info_t *id; id = p_info->debug_info_snap; if (p_info->act_entry == DEBUG_PROLOG_ENTRY) { p_info->act_entry = 0; p_info->act_page = 0; goto out; } if (!id->areas) return 1; p_info->act_entry += id->entry_size; /* switch to next page, if we reached the end of the page */ if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) { /* next page */ p_info->act_entry = 0; p_info->act_page += 1; if ((p_info->act_page % id->pages_per_area) == 0) { /* next area */ p_info->act_area++; p_info->act_page = 0; } if (p_info->act_area >= id->nr_areas) return 1; }out: return 0;} /* * debug_output: * - called for user read() * - copies formatted debug entries to the user buffer */static ssize_t debug_output(struct file *file, /* file descriptor */ char __user *user_buf, /* user buffer */ size_t len, /* length of buffer */ loff_t *offset) /* offset in the file */{ size_t count = 0; size_t entry_offset; file_private_info_t *p_info; p_info = (file_private_info_t *) file->private_data; if (*offset != p_info->offset) return -EPIPE; if (p_info->act_area >= p_info->debug_info_snap->nr_areas) return 0; entry_offset = p_info->act_entry_offset; while (count < len) { int formatted_line_residue; int formatted_line_size; int user_buf_residue; size_t copy_size; formatted_line_size = debug_format_entry(p_info); formatted_line_residue = formatted_line_size - entry_offset; user_buf_residue = len-count; copy_size = min(user_buf_residue, formatted_line_residue); if (copy_size) { if (copy_to_user(user_buf + count, p_info->temp_buf + entry_offset, copy_size)) return -EFAULT; count += copy_size; entry_offset += copy_size; } if (copy_size == formatted_line_residue) { entry_offset = 0; if (debug_next_entry(p_info)) goto out; }Lines 1–500 of 1587. 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// SPDX-License-Identifier: GPL-2.0 /* * S/390 debug facility * * Copyright IBM Corp. 1999, 2020 * * Author(s): Michael Holzheu (holzheu@de.ibm.com), * Holger Smolinski (Holger.Smolinski@de.ibm.com) * * Bugreports to: <Linux390@de.ibm.com> */ #define KMSG_COMPONENT "s390dbf" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include <linux/stddef.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/ctype.h> #include <linux/string.h> #include <linux/sysctl.h> #include <linux/uaccess.h> #include <linux/export.h> #include <linux/init.h> #include <linux/fs.h> #include <linux/minmax.h> #include <linux/debugfs.h> #include <asm/debug.h> #define DEBUG_PROLOG_ENTRY -1 #define ALL_AREAS 0 /* copy all debug areas */ #define NO_AREAS 1 /* copy no debug areas */ /* typedefs */ typedef struct file_private_info { loff_t offset; /* offset of last read in file */ int act_area; /* number of last formatted area */ int act_page; /* act page in given area */ int act_entry; /* last formatted entry (offset */ /* relative to beginning of last */ /* formatted page) */ size_t act_entry_offset; /* up to this offset we copied */ /* in last read the last formatted */ /* entry to userland */ char temp_buf[2048]; /* buffer for output */ debug_info_t *debug_info_org; /* original debug information */ debug_info_t *debug_info_snap; /* snapshot of debug information */ struct debug_view *view; /* used view of debug info */ } file_private_info_t; typedef struct { char *string; /* * This assumes that all args are converted into longs * on L/390 this is the case for all types of parameter * except of floats, and long long (32 bit) * */ long args[]; } debug_sprintf_entry_t; /* internal function prototypes */ static int debug_init(void); static ssize_t debug_output(struct file *file, char __user *user_buf, size_t user_len, loff_t *offset); static ssize_t debug_input(struct file *file, const char __user *user_buf, size_t user_len, loff_t *offset); static int debug_open(struct inode *inode, struct file *file); static int debug_close(struct inode *inode, struct file *file); static debug_info_t *debug_info_create(const char *name, int pages_per_area, int nr_areas, int buf_size, umode_t mode); static void debug_info_get(debug_info_t *); static void debug_info_put(debug_info_t *); static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view, char *out_buf, size_t out_buf_size); static int debug_input_level_fn(debug_info_t *id, struct debug_view *view, struct file *file, const char __user *user_buf, size_t user_buf_size, loff_t *offset); static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view, char *out_buf, size_t out_buf_size); static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view, struct file *file, const char __user *user_buf, size_t user_buf_size, loff_t *offset); static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view, struct file *file, const char __user *user_buf, size_t user_buf_size, loff_t *offset); static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view, char *out_buf, size_t out_buf_size, const char *in_buf); static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view, char *out_buf, size_t out_buf_size, const char *inbuf); static void debug_areas_swap(debug_info_t *a, debug_info_t *b); static void debug_events_append(debug_info_t *dest, debug_info_t *src); /* globals */ struct debug_view debug_hex_ascii_view = { "hex_ascii", NULL, &debug_dflt_header_fn, &debug_hex_ascii_format_fn, NULL, NULL }; EXPORT_SYMBOL(debug_hex_ascii_view); static struct debug_view debug_level_view = { "level", &debug_prolog_level_fn, NULL, NULL, &debug_input_level_fn, NULL }; static struct debug_view debug_pages_view = { "pages", &debug_prolog_pages_fn, NULL, NULL, &debug_input_pages_fn, NULL }; static struct debug_view debug_flush_view = { "flush", NULL, NULL, NULL, &debug_input_flush_fn, NULL }; struct debug_view debug_sprintf_view = { "sprintf", NULL, &debug_dflt_header_fn, &debug_sprintf_format_fn, NULL, NULL }; EXPORT_SYMBOL(debug_sprintf_view); /* used by dump analysis tools to determine version of debug feature */ static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; /* static globals */ static debug_info_t *debug_area_first; static debug_info_t *debug_area_last; static DEFINE_MUTEX(debug_mutex); static int initialized; static int debug_critical; static const struct file_operations debug_file_ops = { .owner = THIS_MODULE, .read = debug_output, .write = debug_input, .open = debug_open, .release = debug_close, }; static struct dentry *debug_debugfs_root_entry; /* functions */ /* * debug_areas_alloc * - Debug areas are implemented as a threedimensonal array: * areas[areanumber][pagenumber][pageoffset] */ static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas) { debug_entry_t ***areas; int i, j; areas = kmalloc_array(nr_areas, sizeof(debug_entry_t **), GFP_KERNEL); if (!areas) goto fail_malloc_areas; for (i = 0; i < nr_areas; i++) { /* GFP_NOWARN to avoid user triggerable WARN, we handle fails */ areas[i] = kmalloc_array(pages_per_area, sizeof(debug_entry_t *), GFP_KERNEL | __GFP_NOWARN); if (!areas[i]) goto fail_malloc_areas2; for (j = 0; j < pages_per_area; j++) { areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL); if (!areas[i][j]) { for (j--; j >= 0 ; j--) kfree(areas[i][j]); kfree(areas[i]); goto fail_malloc_areas2; } } } return areas; fail_malloc_areas2: for (i--; i >= 0; i--) { for (j = 0; j < pages_per_area; j++) kfree(areas[i][j]); kfree(areas[i]); } kfree(areas); fail_malloc_areas: return NULL; } /* * debug_info_alloc * - alloc new debug-info */ static debug_info_t *debug_info_alloc(const char *name, int pages_per_area, int nr_areas, int buf_size, int level, int mode) { debug_info_t *rc; /* alloc everything */ rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL); if (!rc) goto fail_malloc_rc; rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); if (!rc->active_entries) goto fail_malloc_active_entries; rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); if (!rc->active_pages) goto fail_malloc_active_pages; if ((mode == ALL_AREAS) && (pages_per_area != 0)) { rc->areas = debug_areas_alloc(pages_per_area, nr_areas); if (!rc->areas) goto fail_malloc_areas; } else { rc->areas = NULL; } /* initialize members */ spin_lock_init(&rc->lock); rc->pages_per_area = pages_per_area; rc->nr_areas = nr_areas; rc->active_area = 0; rc->level = level; rc->buf_size = buf_size; rc->entry_size = sizeof(debug_entry_t) + buf_size; strscpy(rc->name, name, sizeof(rc->name)); memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *)); memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *)); refcount_set(&(rc->ref_count), 0); return rc; fail_malloc_areas: kfree(rc->active_pages); fail_malloc_active_pages: kfree(rc->active_entries); fail_malloc_active_entries: kfree(rc); fail_malloc_rc: return NULL; } /* * debug_areas_free * - free all debug areas */ static void debug_areas_free(debug_info_t *db_info) { int i, j; if (!db_info->areas) return; for (i = 0; i < db_info->nr_areas; i++) { for (j = 0; j < db_info->pages_per_area; j++) kfree(db_info->areas[i][j]); kfree(db_info->areas[i]); } kfree(db_info->areas); db_info->areas = NULL; } /* * debug_info_free * - free memory debug-info */ static void debug_info_free(debug_info_t *db_info) { debug_areas_free(db_info); kfree(db_info->active_entries); kfree(db_info->active_pages); kfree(db_info); } /* * debug_info_create * - create new debug-info */ static debug_info_t *debug_info_create(const char *name, int pages_per_area, int nr_areas, int buf_size, umode_t mode) { debug_info_t *rc; rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size, DEBUG_DEFAULT_LEVEL, ALL_AREAS); if (!rc) goto out; rc->mode = mode & ~S_IFMT; refcount_set(&rc->ref_count, 1); out: return rc; } /* * debug_info_copy * - copy debug-info */ static debug_info_t *debug_info_copy(debug_info_t *in, int mode) { unsigned long flags; debug_info_t *rc; int i, j; /* get a consistent copy of the debug areas */ do { rc = debug_info_alloc(in->name, in->pages_per_area, in->nr_areas, in->buf_size, in->level, mode); spin_lock_irqsave(&in->lock, flags); if (!rc) goto out; /* has something changed in the meantime ? */ if ((rc->pages_per_area == in->pages_per_area) && (rc->nr_areas == in->nr_areas)) { break; } spin_unlock_irqrestore(&in->lock, flags); debug_info_free(rc); } while (1); if (mode == NO_AREAS) goto out; for (i = 0; i < in->nr_areas; i++) { for (j = 0; j < in->pages_per_area; j++) memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE); } out: spin_unlock_irqrestore(&in->lock, flags); return rc; } /* * debug_info_get * - increments reference count for debug-info */ static void debug_info_get(debug_info_t *db_info) { if (db_info) refcount_inc(&db_info->ref_count); } /* * debug_info_put: * - decreases reference count for debug-info and frees it if necessary */ static void debug_info_put(debug_info_t *db_info) { if (!db_info) return; if (refcount_dec_and_test(&db_info->ref_count)) debug_info_free(db_info); } /* * debug_format_entry: * - format one debug entry and return size of formatted data */ static int debug_format_entry(file_private_info_t *p_info) { debug_info_t *id_snap = p_info->debug_info_snap; struct debug_view *view = p_info->view; debug_entry_t *act_entry; size_t len = 0; if (p_info->act_entry == DEBUG_PROLOG_ENTRY) { /* print prolog */ if (view->prolog_proc) { len += view->prolog_proc(id_snap, view, p_info->temp_buf, sizeof(p_info->temp_buf)); } goto out; } if (!id_snap->areas) /* this is true, if we have a prolog only view */ goto out; /* or if 'pages_per_area' is 0 */ act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area] [p_info->act_page] + p_info->act_entry); if (act_entry->clock == 0LL) goto out; /* empty entry */ if (view->header_proc) { len += view->header_proc(id_snap, view, p_info->act_area, act_entry, p_info->temp_buf + len, sizeof(p_info->temp_buf) - len); } if (view->format_proc) { len += view->format_proc(id_snap, view, p_info->temp_buf + len, sizeof(p_info->temp_buf) - len, DEBUG_DATA(act_entry)); } out: return len; } /* * debug_next_entry: * - goto next entry in p_info */ static inline int debug_next_entry(file_private_info_t *p_info) { debug_info_t *id; id = p_info->debug_info_snap; if (p_info->act_entry == DEBUG_PROLOG_ENTRY) { p_info->act_entry = 0; p_info->act_page = 0; goto out; } if (!id->areas) return 1; p_info->act_entry += id->entry_size; /* switch to next page, if we reached the end of the page */ if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) { /* next page */ p_info->act_entry = 0; p_info->act_page += 1; if ((p_info->act_page % id->pages_per_area) == 0) { /* next area */ p_info->act_area++; p_info->act_page = 0; } if (p_info->act_area >= id->nr_areas) return 1; } out: return 0; } /* * debug_output: * - called for user read() * - copies formatted debug entries to the user buffer */ static ssize_t debug_output(struct file *file, /* file descriptor */ char __user *user_buf, /* user buffer */ size_t len, /* length of buffer */ loff_t *offset) /* offset in the file */ { size_t count = 0; size_t entry_offset; file_private_info_t *p_info; p_info = (file_private_info_t *) file->private_data; if (*offset != p_info->offset) return -EPIPE; if (p_info->act_area >= p_info->debug_info_snap->nr_areas) return 0; entry_offset = p_info->act_entry_offset; while (count < len) { int formatted_line_residue; int formatted_line_size; int user_buf_residue; size_t copy_size; formatted_line_size = debug_format_entry(p_info); formatted_line_residue = formatted_line_size - entry_offset; user_buf_residue = len-count; copy_size = min(user_buf_residue, formatted_line_residue); if (copy_size) { if (copy_to_user(user_buf + count, p_info->temp_buf + entry_offset, copy_size)) return -EFAULT; count += copy_size; entry_offset += copy_size; } if (copy_size == formatted_line_residue) { entry_offset = 0; if (debug_next_entry(p_info)) goto out; }