Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 411 insertions, 0 deletions

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
new file mode 100644
index 000000000000..1627f8d6e0cd
--- /dev/null
+++ b/kernel/kallsyms.c
@@ -0,0 +1,411 @@
+/*
+ * kallsyms.c: in-kernel printing of symbolic oopses and stack traces.
+ *
+ * Rewritten and vastly simplified by Rusty Russell for in-kernel
+ * module loader:
+ *   Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
+ *
+ * ChangeLog:
+ *
+ * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com>
+ *      Changed the compression method from stem compression to "table lookup"
+ *      compression (see scripts/kallsyms.c for a more complete description)
+ */
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/seq_file.h>
+#include <linux/fs.h>
+#include <linux/err.h>
+#include <linux/proc_fs.h>
+#include <linux/mm.h>
+
+#include <asm/sections.h>
+
+#ifdef CONFIG_KALLSYMS_ALL
+#define all_var 1
+#else
+#define all_var 0
+#endif
+
+/* These will be re-linked against their real values during the second link stage */
+extern unsigned long kallsyms_addresses[] __attribute__((weak));
+extern unsigned long kallsyms_num_syms __attribute__((weak,section("data")));
+extern u8 kallsyms_names[] __attribute__((weak));
+
+extern u8 kallsyms_token_table[] __attribute__((weak));
+extern u16 kallsyms_token_index[] __attribute__((weak));
+
+extern unsigned long kallsyms_markers[] __attribute__((weak));
+
+static inline int is_kernel_inittext(unsigned long addr)
+{
+        if (addr >= (unsigned long)_sinittext
+            && addr <= (unsigned long)_einittext)
+                return 1;
+        return 0;
+}
+
+static inline int is_kernel_text(unsigned long addr)
+{
+        if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext)
+                return 1;
+        return in_gate_area_no_task(addr);
+}
+
+static inline int is_kernel(unsigned long addr)
+{
+        if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
+                return 1;
+        return in_gate_area_no_task(addr);
+}
+
+/* expand a compressed symbol data into the resulting uncompressed string,
+   given the offset to where the symbol is in the compressed stream */
+static unsigned int kallsyms_expand_symbol(unsigned int off, char *result)
+{
+        int len, skipped_first = 0;
+        u8 *tptr, *data;
+
+        /* get the compressed symbol length from the first symbol byte */
+        data = &kallsyms_names[off];
+        len = *data;
+        data++;
+
+        /* update the offset to return the offset for the next symbol on
+         * the compressed stream */
+        off += len + 1;
+
+        /* for every byte on the compressed symbol data, copy the table
+           entry for that byte */
+        while(len) {
+                tptr = &kallsyms_token_table[ kallsyms_token_index[*data] ];
+                data++;
+                len--;
+
+                while (*tptr) {
+                        if(skipped_first) {
+                                *result = *tptr;
+                                result++;
+                        } else
+                                skipped_first = 1;
+                        tptr++;
+                }
+        }
+
+        *result = '\0';
+
+        /* return to offset to the next symbol */
+        return off;
+}
+
+/* get symbol type information. This is encoded as a single char at the
+ * begining of the symbol name */
+static char kallsyms_get_symbol_type(unsigned int off)
+{
+        /* get just the first code, look it up in the token table, and return the
+         * first char from this token */
+        return kallsyms_token_table[ kallsyms_token_index[ kallsyms_names[off+1] ] ];
+}
+
+
+/* find the offset on the compressed stream given and index in the
+ * kallsyms array */
+static unsigned int get_symbol_offset(unsigned long pos)
+{
+        u8 *name;
+        int i;
+
+        /* use the closest marker we have. We have markers every 256 positions,
+         * so that should be close enough */
+        name = &kallsyms_names[ kallsyms_markers[pos>>8] ];
+
+        /* sequentially scan all the symbols up to the point we're searching for.
+         * Every symbol is stored in a [<len>][<len> bytes of data] format, so we
+         * just need to add the len to the current pointer for every symbol we
+         * wish to skip */
+        for(i = 0; i < (pos&0xFF); i++)
+                name = name + (*name) + 1;
+
+        return name - kallsyms_names;
+}
+
+/* Lookup the address for this symbol. Returns 0 if not found. */
+unsigned long kallsyms_lookup_name(const char *name)
+{
+        char namebuf[KSYM_NAME_LEN+1];
+        unsigned long i;
+        unsigned int off;
+
+        for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
+                off = kallsyms_expand_symbol(off, namebuf);
+
+                if (strcmp(namebuf, name) == 0)
+                        return kallsyms_addresses[i];
+        }
+        return module_kallsyms_lookup_name(name);
+}
+EXPORT_SYMBOL_GPL(kallsyms_lookup_name);
+
+/*
+ * Lookup an address
+ * - modname is set to NULL if it's in the kernel
+ * - we guarantee that the returned name is valid until we reschedule even if
+ *   it resides in a module
+ * - we also guarantee that modname will be valid until rescheduled
+ */
+const char *kallsyms_lookup(unsigned long addr,
+                            unsigned long *symbolsize,
+                            unsigned long *offset,
+                            char **modname, char *namebuf)
+{
+        unsigned long i, low, high, mid;
+        const char *msym;
+
+        /* This kernel should never had been booted. */
+        BUG_ON(!kallsyms_addresses);
+
+        namebuf[KSYM_NAME_LEN] = 0;
+        namebuf[0] = 0;
+
+        if ((all_var && is_kernel(addr)) ||
+            (!all_var && (is_kernel_text(addr) || is_kernel_inittext(addr)))) {
+                unsigned long symbol_end=0;
+
+                /* do a binary search on the sorted kallsyms_addresses array */
+                low = 0;
+                high = kallsyms_num_syms;
+
+                while (high-low > 1) {
+                        mid = (low + high) / 2;
+                        if (kallsyms_addresses[mid] <= addr) low = mid;
+                        else high = mid;
+                }
+
+                /* search for the first aliased symbol. Aliased symbols are
+                   symbols with the same address */
+                while (low && kallsyms_addresses[low - 1] == kallsyms_addresses[low])
+                        --low;
+
+                /* Grab name */
+                kallsyms_expand_symbol(get_symbol_offset(low), namebuf);
+
+                /* Search for next non-aliased symbol */
+                for (i = low + 1; i < kallsyms_num_syms; i++) {
+                        if (kallsyms_addresses[i] > kallsyms_addresses[low]) {
+                                symbol_end = kallsyms_addresses[i];
+                                break;
+                        }
+                }
+
+                /* if we found no next symbol, we use the end of the section */
+                if (!symbol_end) {
+                        if (is_kernel_inittext(addr))
+                                symbol_end = (unsigned long)_einittext;
+                        else
+                                symbol_end = all_var ? (unsigned long)_end : (unsigned long)_etext;
+                }
+
+                *symbolsize = symbol_end - kallsyms_addresses[low];
+                *modname = NULL;
+                *offset = addr - kallsyms_addresses[low];
+                return namebuf;
+        }
+
+        /* see if it's in a module */
+        msym = module_address_lookup(addr, symbolsize, offset, modname);
+        if (msym)
+                return strncpy(namebuf, msym, KSYM_NAME_LEN);
+
+        return NULL;
+}
+
+/* Replace "%s" in format with address, or returns -errno. */
+void __print_symbol(const char *fmt, unsigned long address)
+{
+        char *modname;
+        const char *name;
+        unsigned long offset, size;
+        char namebuf[KSYM_NAME_LEN+1];
+        char buffer[sizeof("%s+%#lx/%#lx [%s]") + KSYM_NAME_LEN +
+                    2*(BITS_PER_LONG*3/10) + MODULE_NAME_LEN + 1];
+
+        name = kallsyms_lookup(address, &size, &offset, &modname, namebuf);
+
+        if (!name)
+                sprintf(buffer, "0x%lx", address);
+        else {
+                if (modname)
+                        sprintf(buffer, "%s+%#lx/%#lx [%s]", name, offset,
+                                size, modname);
+                else
+                        sprintf(buffer, "%s+%#lx/%#lx", name, offset, size);
+        }
+        printk(fmt, buffer);
+}
+
+/* To avoid using get_symbol_offset for every symbol, we carry prefix along. */
+struct kallsym_iter
+{
+        loff_t pos;
+        struct module *owner;
+        unsigned long value;
+        unsigned int nameoff; /* If iterating in core kernel symbols */
+        char type;
+        char name[KSYM_NAME_LEN+1];
+};
+
+/* Only label it "global" if it is exported. */
+static void upcase_if_global(struct kallsym_iter *iter)
+{
+        if (is_exported(iter->name, iter->owner))
+                iter->type += 'A' - 'a';
+}
+
+static int get_ksymbol_mod(struct kallsym_iter *iter)
+{
+        iter->owner = module_get_kallsym(iter->pos - kallsyms_num_syms,
+                                         &iter->value,
+                                         &iter->type, iter->name);
+        if (iter->owner == NULL)
+                return 0;
+
+        upcase_if_global(iter);
+        return 1;
+}
+
+/* Returns space to next name. */
+static unsigned long get_ksymbol_core(struct kallsym_iter *iter)
+{
+        unsigned off = iter->nameoff;
+
+        iter->owner = NULL;
+        iter->value = kallsyms_addresses[iter->pos];
+
+        iter->type = kallsyms_get_symbol_type(off);
+
+        off = kallsyms_expand_symbol(off, iter->name);
+
+        return off - iter->nameoff;
+}
+
+static void reset_iter(struct kallsym_iter *iter, loff_t new_pos)
+{
+        iter->name[0] = '\0';
+        iter->nameoff = get_symbol_offset(new_pos);
+        iter->pos = new_pos;
+}
+
+/* Returns false if pos at or past end of file. */
+static int update_iter(struct kallsym_iter *iter, loff_t pos)
+{
+        /* Module symbols can be accessed randomly. */
+        if (pos >= kallsyms_num_syms) {
+                iter->pos = pos;
+                return get_ksymbol_mod(iter);
+        }
+        
+        /* If we're not on the desired position, reset to new position. */
+        if (pos != iter->pos)
+                reset_iter(iter, pos);
+
+        iter->nameoff += get_ksymbol_core(iter);
+        iter->pos++;
+
+        return 1;
+}
+
+static void *s_next(struct seq_file *m, void *p, loff_t *pos)
+{
+        (*pos)++;
+
+        if (!update_iter(m->private, *pos))
+                return NULL;
+        return p;
+}
+
+static void *s_start(struct seq_file *m, loff_t *pos)
+{
+        if (!update_iter(m->private, *pos))
+                return NULL;
+        return m->private;
+}
+
+static void s_stop(struct seq_file *m, void *p)
+{
+}
+
+static int s_show(struct seq_file *m, void *p)
+{
+        struct kallsym_iter *iter = m->private;
+
+        /* Some debugging symbols have no name.  Ignore them. */ 
+        if (!iter->name[0])
+                return 0;
+
+        if (iter->owner)
+                seq_printf(m, "%0*lx %c %s\t[%s]\n",
+                           (int)(2*sizeof(void*)),
+                           iter->value, iter->type, iter->name,
+                           module_name(iter->owner));
+        else
+                seq_printf(m, "%0*lx %c %s\n",
+                           (int)(2*sizeof(void*)),
+                           iter->value, iter->type, iter->name);
+        return 0;
+}
+
+static struct seq_operations kallsyms_op = {
+        .start = s_start,
+        .next = s_next,
+        .stop = s_stop,
+        .show = s_show
+};
+
+static int kallsyms_open(struct inode *inode, struct file *file)
+{
+        /* We keep iterator in m->private, since normal case is to
+         * s_start from where we left off, so we avoid doing
+         * using get_symbol_offset for every symbol */
+        struct kallsym_iter *iter;
+        int ret;
+
+        iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+        if (!iter)
+                return -ENOMEM;
+        reset_iter(iter, 0);
+
+        ret = seq_open(file, &kallsyms_op);
+        if (ret == 0)
+                ((struct seq_file *)file->private_data)->private = iter;
+        else
+                kfree(iter);
+        return ret;
+}
+
+static int kallsyms_release(struct inode *inode, struct file *file)
+{
+        struct seq_file *m = (struct seq_file *)file->private_data;
+        kfree(m->private);
+        return seq_release(inode, file);
+}
+
+static struct file_operations kallsyms_operations = {
+        .open = kallsyms_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = kallsyms_release,
+};
+
+static int __init kallsyms_init(void)
+{
+        struct proc_dir_entry *entry;
+
+        entry = create_proc_entry("kallsyms", 0444, NULL);
+        if (entry)
+                entry->proc_fops = &kallsyms_operations;
+        return 0;
+}
+__initcall(kallsyms_init);
+
+EXPORT_SYMBOL(__print_symbol);