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path: root/target/linux/generic/patches-4.1/203-kallsyms_uncompressed.patch
blob: 10cfc83d785e000f2385654686ecacfc0e8b02d2 (plain)
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--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -58,6 +58,7 @@ static struct addr_range percpu_range =
 static struct sym_entry *table;
 static unsigned int table_size, table_cnt;
 static int all_symbols = 0;
+static int uncompressed = 0;
 static int absolute_percpu = 0;
 static char symbol_prefix_char = '\0';
 static unsigned long long kernel_start_addr = 0;
@@ -403,6 +404,9 @@ static void write_src(void)
 
 	free(markers);
 
+	if (uncompressed)
+		return;
+
 	output_label("kallsyms_token_table");
 	off = 0;
 	for (i = 0; i < 256; i++) {
@@ -461,6 +465,9 @@ static void *find_token(unsigned char *s
 {
 	int i;
 
+	if (uncompressed)
+		return NULL;
+
 	for (i = 0; i < len - 1; i++) {
 		if (str[i] == token[0] && str[i+1] == token[1])
 			return &str[i];
@@ -533,6 +540,9 @@ static void optimize_result(void)
 {
 	int i, best;
 
+	if (uncompressed)
+		return;
+
 	/* using the '\0' symbol last allows compress_symbols to use standard
 	 * fast string functions */
 	for (i = 255; i >= 0; i--) {
@@ -703,7 +713,9 @@ int main(int argc, char **argv)
 			} else if (strncmp(argv[i], "--page-offset=", 14) == 0) {
 				const char *p = &argv[i][14];
 				kernel_start_addr = strtoull(p, NULL, 16);
-			} else
+			} else if (strcmp(argv[i], "--uncompressed") == 0)
+				uncompressed = 1;
+			else
 				usage();
 		}
 	} else if (argc != 1)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1334,6 +1334,17 @@ config SYSCTL_ARCH_UNALIGN_ALLOW
 	  the unaligned access emulation.
 	  see arch/parisc/kernel/unaligned.c for reference
 
+config KALLSYMS_UNCOMPRESSED
+	bool "Keep kallsyms uncompressed"
+	depends on KALLSYMS
+	help
+		Normally kallsyms contains compressed symbols (using a token table),
+		reducing the uncompressed kernel image size. Keeping the symbol table
+		uncompressed significantly improves the size of this part in compressed
+		kernel images.
+
+		Say N unless you need compressed kernel images to be small.
+
 config HAVE_PCSPKR_PLATFORM
 	bool
 
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -90,6 +90,10 @@ kallsyms()
 		kallsymopt="${kallsymopt} --absolute-percpu"
 	fi
 
+	if [ -n "${CONFIG_KALLSYMS_UNCOMPRESSED}" ]; then
+		kallsymopt="${kallsymopt} --uncompressed"
+	fi
+
 	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
 		      ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
 
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -109,6 +109,11 @@ static unsigned int kallsyms_expand_symb
 	 * For every byte on the compressed symbol data, copy the table
 	 * entry for that byte.
 	 */
+#ifdef CONFIG_KALLSYMS_UNCOMPRESSED
+	memcpy(result, data + 1, len - 1);
+	result += len - 1;
+	len = 0;
+#endif
 	while (len) {
 		tptr = &kallsyms_token_table[kallsyms_token_index[*data]];
 		data++;
@@ -141,6 +146,9 @@ tail:
  */
 static char kallsyms_get_symbol_type(unsigned int off)
 {
+#ifdef CONFIG_KALLSYMS_UNCOMPRESSED
+	return kallsyms_names[off + 1];
+#endif
 	/*
 	 * Get just the first code, look it up in the token table,
 	 * and return the first char from this token.