Linux-2.6.12-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, 686 insertions, 0 deletions

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
new file mode 100644
index 000000000000..090ffda4adbc
--- /dev/null
+++ b/scripts/kallsyms.c
@@ -0,0 +1,686 @@
+/* Generate assembler source containing symbol information
+ *
+ * Copyright 2002       by Kai Germaschewski
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ *
+ * Usage: nm -n vmlinux | scripts/kallsyms [--all-symbols] > symbols.S
+ *
+ * ChangeLog:
+ *
+ * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com>
+ *      Changed the compression method from stem compression to "table lookup"
+ *      compression
+ *
+ *      Table compression uses all the unused char codes on the symbols and
+ *  maps these to the most used substrings (tokens). For instance, it might
+ *  map char code 0xF7 to represent "write_" and then in every symbol where
+ *  "write_" appears it can be replaced by 0xF7, saving 5 bytes.
+ *      The used codes themselves are also placed in the table so that the
+ *  decompresion can work without "special cases".
+ *      Applied to kernel symbols, this usually produces a compression ratio
+ *  of about 50%.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+/* maximum token length used. It doesn't pay to increase it a lot, because
+ * very long substrings probably don't repeat themselves too often. */
+#define MAX_TOK_SIZE		11
+#define KSYM_NAME_LEN		127
+
+/* we use only a subset of the complete symbol table to gather the token count,
+ * to speed up compression, at the expense of a little compression ratio */
+#define WORKING_SET		1024
+
+/* first find the best token only on the list of tokens that would profit more
+ * than GOOD_BAD_THRESHOLD. Only if this list is empty go to the "bad" list.
+ * Increasing this value will put less tokens on the "good" list, so the search
+ * is faster. However, if the good list runs out of tokens, we must painfully
+ * search the bad list. */
+#define GOOD_BAD_THRESHOLD	10
+
+/* token hash parameters */
+#define HASH_BITS		18
+#define HASH_TABLE_SIZE		(1 << HASH_BITS)
+#define HASH_MASK		(HASH_TABLE_SIZE - 1)
+#define HASH_BASE_OFFSET	2166136261U
+#define HASH_FOLD(a)		((a)&(HASH_MASK))
+
+/* flags to mark symbols */
+#define SYM_FLAG_VALID		1
+#define SYM_FLAG_SAMPLED	2
+
+struct sym_entry {
+	unsigned long long addr;
+	char type;
+	unsigned char flags;
+	unsigned char len;
+	unsigned char *sym;
+};
+
+
+static struct sym_entry *table;
+static int size, cnt;
+static unsigned long long _stext, _etext, _sinittext, _einittext;
+static int all_symbols = 0;
+
+struct token {
+	unsigned char data[MAX_TOK_SIZE];
+	unsigned char len;
+	/* profit: the number of bytes that could be saved by inserting this
+	 * token into the table */
+	int profit;
+	struct token *next;	/* next token on the hash list */
+	struct token *right;	/* next token on the good/bad list */
+	struct token *left;    /* previous token on the good/bad list */
+	struct token *smaller; /* token that is less one letter than this one */
+	};
+
+struct token bad_head, good_head;
+struct token *hash_table[HASH_TABLE_SIZE];
+
+/* the table that holds the result of the compression */
+unsigned char best_table[256][MAX_TOK_SIZE+1];
+unsigned char best_table_len[256];
+
+
+static void
+usage(void)
+{
+	fprintf(stderr, "Usage: kallsyms [--all-symbols] < in.map > out.S\n");
+	exit(1);
+}
+
+/*
+ * This ignores the intensely annoying "mapping symbols" found
+ * in ARM ELF files: $a, $t and $d.
+ */
+static inline int
+is_arm_mapping_symbol(const char *str)
+{
+	return str[0] == '$' && strchr("atd", str[1])
+	       && (str[2] == '\0' || str[2] == '.');
+}
+
+static int
+read_symbol(FILE *in, struct sym_entry *s)
+{
+	char str[500];
+	int rc;
+
+	rc = fscanf(in, "%llx %c %499s\n", &s->addr, &s->type, str);
+	if (rc != 3) {
+		if (rc != EOF) {
+			/* skip line */
+			fgets(str, 500, in);
+		}
+		return -1;
+	}
+
+	/* Ignore most absolute/undefined (?) symbols. */
+	if (strcmp(str, "_stext") == 0)
+		_stext = s->addr;
+	else if (strcmp(str, "_etext") == 0)
+		_etext = s->addr;
+	else if (strcmp(str, "_sinittext") == 0)
+		_sinittext = s->addr;
+	else if (strcmp(str, "_einittext") == 0)
+		_einittext = s->addr;
+	else if (toupper(s->type) == 'A')
+	{
+		/* Keep these useful absolute symbols */
+		if (strcmp(str, "__kernel_syscall_via_break") &&
+		    strcmp(str, "__kernel_syscall_via_epc") &&
+		    strcmp(str, "__kernel_sigtramp") &&
+		    strcmp(str, "__gp"))
+			return -1;
+
+	}
+	else if (toupper(s->type) == 'U' ||
+		 is_arm_mapping_symbol(str))
+		return -1;
+
+	/* include the type field in the symbol name, so that it gets
+	 * compressed together */
+	s->len = strlen(str) + 1;
+	s->sym = (char *) malloc(s->len + 1);
+	strcpy(s->sym + 1, str);
+	s->sym[0] = s->type;
+
+	return 0;
+}
+
+static int
+symbol_valid(struct sym_entry *s)
+{
+	/* Symbols which vary between passes.  Passes 1 and 2 must have
+	 * identical symbol lists.  The kallsyms_* symbols below are only added
+	 * after pass 1, they would be included in pass 2 when --all-symbols is
+	 * specified so exclude them to get a stable symbol list.
+	 */
+	static char *special_symbols[] = {
+		"kallsyms_addresses",
+		"kallsyms_num_syms",
+		"kallsyms_names",
+		"kallsyms_markers",
+		"kallsyms_token_table",
+		"kallsyms_token_index",
+
+	/* Exclude linker generated symbols which vary between passes */
+		"_SDA_BASE_",		/* ppc */
+		"_SDA2_BASE_",		/* ppc */
+		NULL };
+	int i;
+
+	/* if --all-symbols is not specified, then symbols outside the text
+	 * and inittext sections are discarded */
+	if (!all_symbols) {
+		if ((s->addr < _stext || s->addr > _etext)
+		    && (s->addr < _sinittext || s->addr > _einittext))
+			return 0;
+		/* Corner case.  Discard any symbols with the same value as
+		 * _etext or _einittext, they can move between pass 1 and 2
+		 * when the kallsyms data is added.  If these symbols move then
+		 * they may get dropped in pass 2, which breaks the kallsyms
+		 * rules.
+		 */
+		if ((s->addr == _etext && strcmp(s->sym + 1, "_etext")) ||
+		    (s->addr == _einittext && strcmp(s->sym + 1, "_einittext")))
+			return 0;
+	}
+
+	/* Exclude symbols which vary between passes. */
+	if (strstr(s->sym + 1, "_compiled."))
+		return 0;
+
+	for (i = 0; special_symbols[i]; i++)
+		if( strcmp(s->sym + 1, special_symbols[i]) == 0 )
+			return 0;
+
+	return 1;
+}
+
+static void
+read_map(FILE *in)
+{
+	while (!feof(in)) {
+		if (cnt >= size) {
+			size += 10000;
+			table = realloc(table, sizeof(*table) * size);
+			if (!table) {
+				fprintf(stderr, "out of memory\n");
+				exit (1);
+			}
+		}
+		if (read_symbol(in, &table[cnt]) == 0)
+			cnt++;
+	}
+}
+
+static void output_label(char *label)
+{
+	printf(".globl %s\n",label);
+	printf("\tALGN\n");
+	printf("%s:\n",label);
+}
+
+/* uncompress a compressed symbol. When this function is called, the best table
+ * might still be compressed itself, so the function needs to be recursive */
+static int expand_symbol(unsigned char *data, int len, char *result)
+{
+	int c, rlen, total=0;
+
+	while (len) {
+		c = *data;
+		/* if the table holds a single char that is the same as the one
+		 * we are looking for, then end the search */
+		if (best_table[c][0]==c && best_table_len[c]==1) {
+			*result++ = c;
+			total++;
+		} else {
+			/* if not, recurse and expand */
+			rlen = expand_symbol(best_table[c], best_table_len[c], result);
+			total += rlen;
+			result += rlen;
+		}
+		data++;
+		len--;
+	}
+	*result=0;
+
+	return total;
+}
+
+static void
+write_src(void)
+{
+	int i, k, off, valid;
+	unsigned int best_idx[256];
+	unsigned int *markers;
+	char buf[KSYM_NAME_LEN+1];
+
+	printf("#include <asm/types.h>\n");
+	printf("#if BITS_PER_LONG == 64\n");
+	printf("#define PTR .quad\n");
+	printf("#define ALGN .align 8\n");
+	printf("#else\n");
+	printf("#define PTR .long\n");
+	printf("#define ALGN .align 4\n");
+	printf("#endif\n");
+
+	printf(".data\n");
+
+	output_label("kallsyms_addresses");
+	valid = 0;
+	for (i = 0; i < cnt; i++) {
+		if (table[i].flags & SYM_FLAG_VALID) {
+			printf("\tPTR\t%#llx\n", table[i].addr);
+			valid++;
+		}
+	}
+	printf("\n");
+
+	output_label("kallsyms_num_syms");
+	printf("\tPTR\t%d\n", valid);
+	printf("\n");
+
+	/* table of offset markers, that give the offset in the compressed stream
+	 * every 256 symbols */
+	markers = (unsigned int *) malloc(sizeof(unsigned int)*((valid + 255) / 256));
+
+	output_label("kallsyms_names");
+	valid = 0;
+	off = 0;
+	for (i = 0; i < cnt; i++) {
+
+		if (!table[i].flags & SYM_FLAG_VALID)
+			continue;
+
+		if ((valid & 0xFF) == 0)
+			markers[valid >> 8] = off;
+
+		printf("\t.byte 0x%02x", table[i].len);
+		for (k = 0; k < table[i].len; k++)
+			printf(", 0x%02x", table[i].sym[k]);
+		printf("\n");
+
+		off += table[i].len + 1;
+		valid++;
+	}
+	printf("\n");
+
+	output_label("kallsyms_markers");
+	for (i = 0; i < ((valid + 255) >> 8); i++)
+		printf("\tPTR\t%d\n", markers[i]);
+	printf("\n");
+
+	free(markers);
+
+	output_label("kallsyms_token_table");
+	off = 0;
+	for (i = 0; i < 256; i++) {
+		best_idx[i] = off;
+		expand_symbol(best_table[i],best_table_len[i],buf);
+		printf("\t.asciz\t\"%s\"\n", buf);
+		off += strlen(buf) + 1;
+	}
+	printf("\n");
+
+	output_label("kallsyms_token_index");
+	for (i = 0; i < 256; i++)
+		printf("\t.short\t%d\n", best_idx[i]);
+	printf("\n");
+}
+
+
+/* table lookup compression functions */
+
+static inline unsigned int rehash_token(unsigned int hash, unsigned char data)
+{
+	return ((hash * 16777619) ^ data);
+}
+
+static unsigned int hash_token(unsigned char *data, int len)
+{
+	unsigned int hash=HASH_BASE_OFFSET;
+	int i;
+
+	for (i = 0; i < len; i++)
+		hash = rehash_token(hash, data[i]);
+
+	return HASH_FOLD(hash);
+}
+
+/* find a token given its data and hash value */
+static struct token *find_token_hash(unsigned char *data, int len, unsigned int hash)
+{
+	struct token *ptr;
+
+	ptr = hash_table[hash];
+
+	while (ptr) {
+		if ((ptr->len == len) && (memcmp(ptr->data, data, len) == 0))
+			return ptr;
+		ptr=ptr->next;
+	}
+
+	return NULL;
+}
+
+static inline void insert_token_in_group(struct token *head, struct token *ptr)
+{
+	ptr->right = head->right;
+	ptr->right->left = ptr;
+	head->right = ptr;
+	ptr->left = head;
+}
+
+static inline void remove_token_from_group(struct token *ptr)
+{
+	ptr->left->right = ptr->right;
+	ptr->right->left = ptr->left;
+}
+
+
+/* build the counts for all the tokens that start with "data", and have lenghts
+ * from 2 to "len" */
+static void learn_token(unsigned char *data, int len)
+{
+	struct token *ptr,*last_ptr;
+	int i, newprofit;
+	unsigned int hash = HASH_BASE_OFFSET;
+	unsigned int hashes[MAX_TOK_SIZE + 1];
+
+	if (len > MAX_TOK_SIZE)
+		len = MAX_TOK_SIZE;
+
+	/* calculate and store the hash values for all the sub-tokens */
+	hash = rehash_token(hash, data[0]);
+	for (i = 2; i <= len; i++) {
+		hash = rehash_token(hash, data[i-1]);
+		hashes[i] = HASH_FOLD(hash);
+	}
+
+	last_ptr = NULL;
+	ptr = NULL;
+
+	for (i = len; i >= 2; i--) {
+		hash = hashes[i];
+
+		if (!ptr) ptr = find_token_hash(data, i, hash);
+
+		if (!ptr) {
+			/* create a new token entry */
+			ptr = (struct token *) malloc(sizeof(*ptr));
+
+			memcpy(ptr->data, data, i);
+			ptr->len = i;
+
+			/* when we create an entry, it's profit is 0 because
+			 * we also take into account the size of the token on
+			 * the compressed table. We then subtract GOOD_BAD_THRESHOLD
+			 * so that the test to see if this token belongs to
+			 * the good or bad list, is a comparison to zero */
+			ptr->profit = -GOOD_BAD_THRESHOLD;
+
+			ptr->next = hash_table[hash];
+			hash_table[hash] = ptr;
+
+			insert_token_in_group(&bad_head, ptr);
+
+			ptr->smaller = NULL;
+		} else {
+			newprofit = ptr->profit + (ptr->len - 1);
+			/* check to see if this token needs to be moved to a
+			 * different list */
+			if((ptr->profit < 0) && (newprofit >= 0)) {
+				remove_token_from_group(ptr);
+				insert_token_in_group(&good_head,ptr);
+			}
+			ptr->profit = newprofit;
+		}
+
+		if (last_ptr) last_ptr->smaller = ptr;
+		last_ptr = ptr;
+
+		ptr = ptr->smaller;
+	}
+}
+
+/* decrease the counts for all the tokens that start with "data", and have lenghts
+ * from 2 to "len". This function is much simpler than learn_token because we have
+ * more guarantees (tho tokens exist, the ->smaller pointer is set, etc.)
+ * The two separate functions exist only because of compression performance */
+static void forget_token(unsigned char *data, int len)
+{
+	struct token *ptr;
+	int i, newprofit;
+	unsigned int hash=0;
+
+	if (len > MAX_TOK_SIZE) len = MAX_TOK_SIZE;
+
+	hash = hash_token(data, len);
+	ptr = find_token_hash(data, len, hash);
+
+	for (i = len; i >= 2; i--) {
+
+		newprofit = ptr->profit - (ptr->len - 1);
+		if ((ptr->profit >= 0) && (newprofit < 0)) {
+			remove_token_from_group(ptr);
+			insert_token_in_group(&bad_head, ptr);
+		}
+		ptr->profit=newprofit;
+
+		ptr=ptr->smaller;
+	}
+}
+
+/* count all the possible tokens in a symbol */
+static void learn_symbol(unsigned char *symbol, int len)
+{
+	int i;
+
+	for (i = 0; i < len - 1; i++)
+		learn_token(symbol + i, len - i);
+}
+
+/* decrease the count for all the possible tokens in a symbol */
+static void forget_symbol(unsigned char *symbol, int len)
+{
+	int i;
+
+	for (i = 0; i < len - 1; i++)
+		forget_token(symbol + i, len - i);
+}
+
+/* set all the symbol flags and do the initial token count */
+static void build_initial_tok_table(void)
+{
+	int i, use_it, valid;
+
+	valid = 0;
+	for (i = 0; i < cnt; i++) {
+		table[i].flags = 0;
+		if ( symbol_valid(&table[i]) ) {
+			table[i].flags |= SYM_FLAG_VALID;
+			valid++;
+		}
+	}
+
+	use_it = 0;
+	for (i = 0; i < cnt; i++) {
+
+		/* subsample the available symbols. This method is almost like
+		 * a Bresenham's algorithm to get uniformly distributed samples
+		 * across the symbol table */
+		if (table[i].flags & SYM_FLAG_VALID) {
+
+			use_it += WORKING_SET;
+
+			if (use_it >= valid) {
+				table[i].flags |= SYM_FLAG_SAMPLED;
+				use_it -= valid;
+			}
+		}
+		if (table[i].flags & SYM_FLAG_SAMPLED)
+			learn_symbol(table[i].sym, table[i].len);
+	}
+}
+
+/* replace a given token in all the valid symbols. Use the sampled symbols
+ * to update the counts */
+static void compress_symbols(unsigned char *str, int tlen, int idx)
+{
+	int i, len, learn, size;
+	unsigned char *p;
+
+	for (i = 0; i < cnt; i++) {
+
+		if (!(table[i].flags & SYM_FLAG_VALID)) continue;
+
+		len = table[i].len;
+		learn = 0;
+		p = table[i].sym;
+
+		do {
+			/* find the token on the symbol */
+			p = (unsigned char *) strstr((char *) p, (char *) str);
+			if (!p) break;
+
+			if (!learn) {
+				/* if this symbol was used to count, decrease it */
+				if (table[i].flags & SYM_FLAG_SAMPLED)
+					forget_symbol(table[i].sym, len);
+				learn = 1;
+			}
+
+			*p = idx;
+			size = (len - (p - table[i].sym)) - tlen + 1;
+			memmove(p + 1, p + tlen, size);
+			p++;
+			len -= tlen - 1;
+
+		} while (size >= tlen);
+
+		if(learn) {
+			table[i].len = len;
+			/* if this symbol was used to count, learn it again */
+			if(table[i].flags & SYM_FLAG_SAMPLED)
+				learn_symbol(table[i].sym, len);
+		}
+	}
+}
+
+/* search the token with the maximum profit */
+static struct token *find_best_token(void)
+{
+	struct token *ptr,*best,*head;
+	int bestprofit;
+
+	bestprofit=-10000;
+
+	/* failsafe: if the "good" list is empty search from the "bad" list */
+	if(good_head.right == &good_head) head = &bad_head;
+	else head = &good_head;
+
+	ptr = head->right;
+	best = NULL;
+	while (ptr != head) {
+		if (ptr->profit > bestprofit) {
+			bestprofit = ptr->profit;
+			best = ptr;
+		}
+		ptr = ptr->right;
+	}
+
+	return best;
+}
+
+/* this is the core of the algorithm: calculate the "best" table */
+static void optimize_result(void)
+{
+	struct token *best;
+	int i;
+
+	/* using the '\0' symbol last allows compress_symbols to use standard
+	 * fast string functions */
+	for (i = 255; i >= 0; i--) {
+
+		/* if this table slot is empty (it is not used by an actual
+		 * original char code */
+		if (!best_table_len[i]) {
+
+			/* find the token with the breates profit value */
+			best = find_best_token();
+
+			/* place it in the "best" table */
+			best_table_len[i] = best->len;
+			memcpy(best_table[i], best->data, best_table_len[i]);
+			/* zero terminate the token so that we can use strstr
+			   in compress_symbols */
+			best_table[i][best_table_len[i]]='\0';
+
+			/* replace this token in all the valid symbols */
+			compress_symbols(best_table[i], best_table_len[i], i);
+		}
+	}
+}
+
+/* start by placing the symbols that are actually used on the table */
+static void insert_real_symbols_in_table(void)
+{
+	int i, j, c;
+
+	memset(best_table, 0, sizeof(best_table));
+	memset(best_table_len, 0, sizeof(best_table_len));
+
+	for (i = 0; i < cnt; i++) {
+		if (table[i].flags & SYM_FLAG_VALID) {
+			for (j = 0; j < table[i].len; j++) {
+				c = table[i].sym[j];
+				best_table[c][0]=c;
+				best_table_len[c]=1;
+			}
+		}
+	}
+}
+
+static void optimize_token_table(void)
+{
+	memset(hash_table, 0, sizeof(hash_table));
+
+	good_head.left = &good_head;
+	good_head.right = &good_head;
+
+	bad_head.left = &bad_head;
+	bad_head.right = &bad_head;
+
+	build_initial_tok_table();
+
+	insert_real_symbols_in_table();
+
+	optimize_result();
+}
+
+
+int
+main(int argc, char **argv)
+{
+	if (argc == 2 && strcmp(argv[1], "--all-symbols") == 0)
+		all_symbols = 1;
+	else if (argc != 1)
+		usage();
+
+	read_map(stdin);
+	optimize_token_table();
+	write_src();
+
+	return 0;
+}
+