[PATCH 00/16] scripts/kallsyms: various cleanups and optimizations

[PATCH 00/16] scripts/kallsyms: various cleanups and optimizations

[Masahiro Yamada]

Masahiro Yamada (16):
  scripts/kallsyms: remove unneeded #ifndef ARRAY_SIZE
  scripts/kallsyms: fix definitely-lost memory leak
  scripts/kallsyms: set relative_base more effectively
  scripts/kallsyms: remove redundant is_arm_mapping_symbol()
  scripts/kallsyms: remove unneeded length check for prefix matching
  scripts/kallsyms: add sym_name() to mitigate cast ugliness
  scripts/kallsyms: replace prefix_underscores_count() with strspn()
  scripts/kallsyms: make find_token() return (unsigned char *)
  scripts/kallsyms: add const qualifiers where possible
  scripts/kallsyms: skip ignored symbols very early
  scripts/kallsyms: move more patterns to the ignored_prefixes array
  scripts/kallsyms: move ignored symbol types to is_ignored_symbol()
  scripts/kallsyms: make check_symbol_range() void function
  scripts/kallsyms: check no valid symbol earlier
  scripts/kallsyms: put check_symbol_range() calls close together
  scripts/kallsyms: remove redundant initializers

 scripts/kallsyms.c | 254 +++++++++++++++++++++------------------------
 1 file changed, 121 insertions(+), 133 deletions(-)

-- 
2.17.1

[PATCH 01/16] scripts/kallsyms: remove unneeded #ifndef ARRAY_SIZE

[Masahiro Yamada]

This is not defined in the standard headers. #ifndef is unneeded.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index ae6504d07fd6..918c2ba071b5 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -24,9 +24,7 @@
 #include <ctype.h>
 #include <limits.h>
 
-#ifndef ARRAY_SIZE
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
-#endif
 
 #define KSYM_NAME_LEN		128
 
-- 
2.17.1

[PATCH 02/16] scripts/kallsyms: fix definitely-lost memory leak

[Masahiro Yamada]

build_initial_tok_table() overwrites unused sym_entry to shrink the
table size. Before the entry is overwritten, table[i].sym must be freed
since it is malloc'ed data.

This fixes the 'definitely lost' report from valgrind. I ran valgrind
against x86_64_defconfig of v5.4-rc8 kernel, and here is the summary:

[Before the fix]

  LEAK SUMMARY:
     definitely lost: 53,184 bytes in 2,874 blocks

[After the fix]

  LEAK SUMMARY:
     definitely lost: 0 bytes in 0 blocks

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 918c2ba071b5..79641874d860 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -487,6 +487,8 @@ static void build_initial_tok_table(void)
 				table[pos] = table[i];
 			learn_symbol(table[pos].sym, table[pos].len);
 			pos++;
+		} else {
+			free(table[i].sym);
 		}
 	}
 	table_cnt = pos;
-- 
2.17.1

[PATCH 03/16] scripts/kallsyms: set relative_base more effectively

[Masahiro Yamada]

Currently, record_relative_base() iterates over the entire table to
find the minimum address, but it is not efficient because we sort
the table anyway.

After sort_symbol(), the table is sorted by address. (kallsyms parses
the 'nm -n' output, so the data is already sorted by address, but this
commit does not rely on it.)

Move record_relative_base() after sort_symbols(), and take the first
non-absolute symbol value.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 79641874d860..0959e1de381c 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -731,11 +731,15 @@ static void record_relative_base(void)
 {
 	unsigned int i;
 
-	relative_base = -1ULL;
 	for (i = 0; i < table_cnt; i++)
-		if (!symbol_absolute(&table[i]) &&
-		    table[i].addr < relative_base)
+		if (!symbol_absolute(&table[i])) {
+			/*
+			 * The table is sorted by address.
+			 * Take the first non-absolute symbol value.
+			 */
 			relative_base = table[i].addr;
+			return;
+		}
 }
 
 int main(int argc, char **argv)
@@ -758,9 +762,9 @@ int main(int argc, char **argv)
 	read_map(stdin);
 	if (absolute_percpu)
 		make_percpus_absolute();
+	sort_symbols();
 	if (base_relative)
 		record_relative_base();
-	sort_symbols();
 	optimize_token_table();
 	write_src();
 
-- 
2.17.1

[PATCH 04/16] scripts/kallsyms: remove redundant is_arm_mapping_symbol()

[Masahiro Yamada]

Since commit 6f00df24ee39 ("[PATCH] Strip local symbols from kallsyms"),
all symbols starting '$' are ignored.

is_arm_mapping_symbol() particularly ignores $a, $t, etc. but it is
redundant.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 0959e1de381c..265475d3cffb 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -74,16 +74,6 @@ static void usage(void)
 	exit(1);
 }
 
-/*
- * This ignores the intensely annoying "mapping symbols" found
- * in ARM ELF files: $a, $t and $d.
- */
-static int is_arm_mapping_symbol(const char *str)
-{
-	return str[0] == '$' && strchr("axtd", str[1])
-	       && (str[2] == '\0' || str[2] == '.');
-}
-
 static int check_symbol_range(const char *sym, unsigned long long addr,
 			      struct addr_range *ranges, int entries)
 {
@@ -139,10 +129,13 @@ static int read_symbol(FILE *in, struct sym_entry *s)
 			return -1;
 
 	}
-	else if (toupper(stype) == 'U' ||
-		 is_arm_mapping_symbol(sym))
+	else if (toupper(stype) == 'U')
 		return -1;
-	/* exclude also MIPS ELF local symbols ($L123 instead of .L123) */
+	/*
+	 * Ignore generated symbols such as:
+	 *  - mapping symbols in ARM ELF files ($a, $t, and $d)
+	 *  - MIPS ELF local symbols ($L123 instead of .L123)
+	 */
 	else if (sym[0] == '$')
 		return -1;
 	/* exclude debugging symbols */
-- 
2.17.1

[PATCH 05/16] scripts/kallsyms: remove unneeded length check for prefix matching

[Masahiro Yamada]

l <= strlen(sym_name) is unnecessary for prefix matching.
strncmp() will do.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 265475d3cffb..d06f373b3a96 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -246,8 +246,7 @@ static int symbol_valid(struct sym_entry *s)
 	for (i = 0; special_prefixes[i]; i++) {
 		int l = strlen(special_prefixes[i]);
 
-		if (l <= strlen(sym_name) &&
-		    strncmp(sym_name, special_prefixes[i], l) == 0)
+		if (strncmp(sym_name, special_prefixes[i], l) == 0)
 			return 0;
 	}
 
-- 
2.17.1

[PATCH 06/16] scripts/kallsyms: add sym_name() to mitigate cast ugliness

[Masahiro Yamada]

sym_entry::sym is (unsigned char *) instead of (char *) because
kallsyms exploits the MSB for compression, and the characters are
used as the index of token_profit array.

However, it requires casting (unsigned char *) to (char *) in some
places since standard library functions such as strcmp(), strlen()
expect (char *).

Introduce a new helper, sym_name(), which advances the given pointer
by 1 and casts it to (char *).

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index d06f373b3a96..7b00b4030be4 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -74,6 +74,11 @@ static void usage(void)
 	exit(1);
 }
 
+static char *sym_name(const struct sym_entry *s)
+{
+	return (char *)s->sym + 1;
+}
+
 static int check_symbol_range(const char *sym, unsigned long long addr,
 			      struct addr_range *ranges, int entries)
 {
@@ -154,7 +159,7 @@ static int read_symbol(FILE *in, struct sym_entry *s)
 			"unable to allocate required amount of memory\n");
 		exit(EXIT_FAILURE);
 	}
-	strcpy((char *)s->sym + 1, sym);
+	strcpy(sym_name(s), sym);
 	s->sym[0] = stype;
 
 	s->percpu_absolute = 0;
@@ -215,7 +220,7 @@ static int symbol_valid(struct sym_entry *s)
 		NULL };
 
 	int i;
-	char *sym_name = (char *)s->sym + 1;
+	const char *name = sym_name(s);
 
 	/* if --all-symbols is not specified, then symbols outside the text
 	 * and inittext sections are discarded */
@@ -230,30 +235,28 @@ static int symbol_valid(struct sym_entry *s)
 		 * rules.
 		 */
 		if ((s->addr == text_range_text->end &&
-				strcmp(sym_name,
-				       text_range_text->end_sym)) ||
+		     strcmp(name, text_range_text->end_sym)) ||
 		    (s->addr == text_range_inittext->end &&
-				strcmp(sym_name,
-				       text_range_inittext->end_sym)))
+		     strcmp(name, text_range_inittext->end_sym)))
 			return 0;
 	}
 
 	/* Exclude symbols which vary between passes. */
 	for (i = 0; special_symbols[i]; i++)
-		if (strcmp(sym_name, special_symbols[i]) == 0)
+		if (strcmp(name, special_symbols[i]) == 0)
 			return 0;
 
 	for (i = 0; special_prefixes[i]; i++) {
 		int l = strlen(special_prefixes[i]);
 
-		if (strncmp(sym_name, special_prefixes[i], l) == 0)
+		if (strncmp(name, special_prefixes[i], l) == 0)
 			return 0;
 	}
 
 	for (i = 0; special_suffixes[i]; i++) {
-		int l = strlen(sym_name) - strlen(special_suffixes[i]);
+		int l = strlen(name) - strlen(special_suffixes[i]);
 
-		if (l >= 0 && strcmp(sym_name + l, special_suffixes[i]) == 0)
+		if (l >= 0 && strcmp(name + l, special_suffixes[i]) == 0)
 			return 0;
 	}
 
@@ -618,7 +621,7 @@ static void optimize_token_table(void)
 /* guess for "linker script provide" symbol */
 static int may_be_linker_script_provide_symbol(const struct sym_entry *se)
 {
-	const char *symbol = (char *)se->sym + 1;
+	const char *symbol = sym_name(se);
 	int len = se->len - 1;
 
 	if (len < 8)
@@ -688,8 +691,8 @@ static int compare_symbols(const void *a, const void *b)
 		return wa - wb;
 
 	/* sort by the number of prefix underscores */
-	wa = prefix_underscores_count((const char *)sa->sym + 1);
-	wb = prefix_underscores_count((const char *)sb->sym + 1);
+	wa = prefix_underscores_count(sym_name(sa));
+	wb = prefix_underscores_count(sym_name(sb));
 	if (wa != wb)
 		return wa - wb;
 
-- 
2.17.1

[PATCH 07/16] scripts/kallsyms: replace prefix_underscores_count() with strspn()

[Masahiro Yamada]

You can do equivalent with strspn(). I do not see noticeable performance
difference.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 7b00b4030be4..a007d901c3a5 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -653,16 +653,6 @@ static int may_be_linker_script_provide_symbol(const struct sym_entry *se)
 	return 0;
 }
 
-static int prefix_underscores_count(const char *str)
-{
-	const char *tail = str;
-
-	while (*tail == '_')
-		tail++;
-
-	return tail - str;
-}
-
 static int compare_symbols(const void *a, const void *b)
 {
 	const struct sym_entry *sa;
@@ -691,8 +681,8 @@ static int compare_symbols(const void *a, const void *b)
 		return wa - wb;
 
 	/* sort by the number of prefix underscores */
-	wa = prefix_underscores_count(sym_name(sa));
-	wb = prefix_underscores_count(sym_name(sb));
+	wa = strspn(sym_name(sa), "_");
+	wb = strspn(sym_name(sb), "_");
 	if (wa != wb)
 		return wa - wb;
 
-- 
2.17.1

[PATCH 08/16] scripts/kallsyms: make find_token() return (unsigned char *)

[Masahiro Yamada]

The callers of this function expect (unsigned char *). I do not see
a good reason to make this function return (void *).

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index a007d901c3a5..c4f7f20ecfb7 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -489,7 +489,8 @@ static void build_initial_tok_table(void)
 	table_cnt = pos;
 }
 
-static void *find_token(unsigned char *str, int len, unsigned char *token)
+static unsigned char *find_token(unsigned char *str, int len,
+				 unsigned char *token)
 {
 	int i;
 
-- 
2.17.1

[PATCH 09/16] scripts/kallsyms: add const qualifiers where possible

[Masahiro Yamada]

Add 'const' where a function does not write to the pointer dereferenes.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index c4f7f20ecfb7..d745fd2c7247 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -170,11 +170,11 @@ static int read_symbol(FILE *in, struct sym_entry *s)
 	return 0;
 }
 
-static int symbol_in_range(struct sym_entry *s, struct addr_range *ranges,
-			   int entries)
+static int symbol_in_range(const struct sym_entry *s,
+			   const struct addr_range *ranges, int entries)
 {
 	size_t i;
-	struct addr_range *ar;
+	const struct addr_range *ar;
 
 	for (i = 0; i < entries; ++i) {
 		ar = &ranges[i];
@@ -186,14 +186,14 @@ static int symbol_in_range(struct sym_entry *s, struct addr_range *ranges,
 	return 0;
 }
 
-static int symbol_valid(struct sym_entry *s)
+static int symbol_valid(const 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[] = {
+	static const char * const special_symbols[] = {
 		"kallsyms_addresses",
 		"kallsyms_offsets",
 		"kallsyms_relative_base",
@@ -208,12 +208,12 @@ static int symbol_valid(struct sym_entry *s)
 		"_SDA2_BASE_",		/* ppc */
 		NULL };
 
-	static char *special_prefixes[] = {
+	static const char * const special_prefixes[] = {
 		"__crc_",		/* modversions */
 		"__efistub_",		/* arm64 EFI stub namespace */
 		NULL };
 
-	static char *special_suffixes[] = {
+	static const char * const special_suffixes[] = {
 		"_veneer",		/* arm */
 		"_from_arm",		/* arm */
 		"_from_thumb",		/* arm */
@@ -281,7 +281,7 @@ static void read_map(FILE *in)
 	}
 }
 
-static void output_label(char *label)
+static void output_label(const char *label)
 {
 	printf(".globl %s\n", label);
 	printf("\tALGN\n");
@@ -290,7 +290,7 @@ static void output_label(char *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)
+static int expand_symbol(const unsigned char *data, int len, char *result)
 {
 	int c, rlen, total=0;
 
@@ -315,7 +315,7 @@ static int expand_symbol(unsigned char *data, int len, char *result)
 	return total;
 }
 
-static int symbol_absolute(struct sym_entry *s)
+static int symbol_absolute(const struct sym_entry *s)
 {
 	return s->percpu_absolute;
 }
@@ -453,7 +453,7 @@ static void write_src(void)
 /* table lookup compression functions */
 
 /* count all the possible tokens in a symbol */
-static void learn_symbol(unsigned char *symbol, int len)
+static void learn_symbol(const unsigned char *symbol, int len)
 {
 	int i;
 
@@ -462,7 +462,7 @@ static void learn_symbol(unsigned char *symbol, int len)
 }
 
 /* decrease the count for all the possible tokens in a symbol */
-static void forget_symbol(unsigned char *symbol, int len)
+static void forget_symbol(const unsigned char *symbol, int len)
 {
 	int i;
 
@@ -490,7 +490,7 @@ static void build_initial_tok_table(void)
 }
 
 static unsigned char *find_token(unsigned char *str, int len,
-				 unsigned char *token)
+				 const unsigned char *token)
 {
 	int i;
 
@@ -503,7 +503,7 @@ static unsigned char *find_token(unsigned char *str, int 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 idx)
+static void compress_symbols(const unsigned char *str, int idx)
 {
 	unsigned int i, len, size;
 	unsigned char *p1, *p2;
-- 
2.17.1

[PATCH 10/16] scripts/kallsyms: skip ignored symbols very early

[Masahiro Yamada]

Unless the address range matters, symbols can be ignored earlier,
which avoids unneeded memory allocation.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 113 +++++++++++++++++++++++++--------------------
 1 file changed, 62 insertions(+), 51 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index d745fd2c7247..5553843631d4 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -18,6 +18,7 @@
  *
  */
 
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -79,6 +80,64 @@ static char *sym_name(const struct sym_entry *s)
 	return (char *)s->sym + 1;
 }
 
+static bool is_ignored_symbol(const char *name, char type)
+{
+	static const char * const ignored_symbols[] = {
+		/*
+		 * 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.
+		 */
+		"kallsyms_addresses",
+		"kallsyms_offsets",
+		"kallsyms_relative_base",
+		"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
+	};
+
+	static const char * const ignored_prefixes[] = {
+		"__crc_",		/* modversions */
+		"__efistub_",		/* arm64 EFI stub namespace */
+		NULL
+	};
+
+	static const char * const ignored_suffixes[] = {
+		"_from_arm",		/* arm */
+		"_from_thumb",		/* arm */
+		"_veneer",		/* arm */
+		NULL
+	};
+
+	const char * const *p;
+
+	/* Exclude symbols which vary between passes. */
+	for (p = ignored_symbols; *p; p++)
+		if (!strcmp(name, *p))
+			return true;
+
+	for (p = ignored_prefixes; *p; p++)
+		if (!strncmp(name, *p, strlen(*p)))
+			return true;
+
+	for (p = ignored_suffixes; *p; p++) {
+		int l = strlen(name) - strlen(*p);
+
+		if (l >= 0 && !strcmp(name + l, *p))
+			return true;
+	}
+
+	return false;
+}
+
 static int check_symbol_range(const char *sym, unsigned long long addr,
 			      struct addr_range *ranges, int entries)
 {
@@ -118,6 +177,9 @@ static int read_symbol(FILE *in, struct sym_entry *s)
 		return -1;
 	}
 
+	if (is_ignored_symbol(sym, stype))
+		return -1;
+
 	/* Ignore most absolute/undefined (?) symbols. */
 	if (strcmp(sym, "_text") == 0)
 		_text = s->addr;
@@ -188,38 +250,6 @@ static int symbol_in_range(const struct sym_entry *s,
 
 static int symbol_valid(const 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 const char * const special_symbols[] = {
-		"kallsyms_addresses",
-		"kallsyms_offsets",
-		"kallsyms_relative_base",
-		"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 };
-
-	static const char * const special_prefixes[] = {
-		"__crc_",		/* modversions */
-		"__efistub_",		/* arm64 EFI stub namespace */
-		NULL };
-
-	static const char * const special_suffixes[] = {
-		"_veneer",		/* arm */
-		"_from_arm",		/* arm */
-		"_from_thumb",		/* arm */
-		NULL };
-
-	int i;
 	const char *name = sym_name(s);
 
 	/* if --all-symbols is not specified, then symbols outside the text
@@ -241,25 +271,6 @@ static int symbol_valid(const struct sym_entry *s)
 			return 0;
 	}
 
-	/* Exclude symbols which vary between passes. */
-	for (i = 0; special_symbols[i]; i++)
-		if (strcmp(name, special_symbols[i]) == 0)
-			return 0;
-
-	for (i = 0; special_prefixes[i]; i++) {
-		int l = strlen(special_prefixes[i]);
-
-		if (strncmp(name, special_prefixes[i], l) == 0)
-			return 0;
-	}
-
-	for (i = 0; special_suffixes[i]; i++) {
-		int l = strlen(name) - strlen(special_suffixes[i]);
-
-		if (l >= 0 && strcmp(name + l, special_suffixes[i]) == 0)
-			return 0;
-	}
-
 	return 1;
 }
 
-- 
2.17.1

[PATCH 11/16] scripts/kallsyms: move more patterns to the ignored_prefixes array

[Masahiro Yamada]

Refactoring for shortening the code.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 5553843631d4..63473924d4de 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -105,6 +105,8 @@ static bool is_ignored_symbol(const char *name, char type)
 	};
 
 	static const char * const ignored_prefixes[] = {
+		"$",			/* local symbols for ARM, MIPS, etc. */
+		".LASANPC",		/* s390 kasan local symbols */
 		"__crc_",		/* modversions */
 		"__efistub_",		/* arm64 EFI stub namespace */
 		NULL
@@ -198,19 +200,9 @@ static int read_symbol(FILE *in, struct sym_entry *s)
 	}
 	else if (toupper(stype) == 'U')
 		return -1;
-	/*
-	 * Ignore generated symbols such as:
-	 *  - mapping symbols in ARM ELF files ($a, $t, and $d)
-	 *  - MIPS ELF local symbols ($L123 instead of .L123)
-	 */
-	else if (sym[0] == '$')
-		return -1;
 	/* exclude debugging symbols */
 	else if (stype == 'N' || stype == 'n')
 		return -1;
-	/* exclude s390 kasan local symbols */
-	else if (!strncmp(sym, ".LASANPC", 8))
-		return -1;
 
 	/* include the type field in the symbol name, so that it gets
 	 * compressed together */
-- 
2.17.1

[PATCH 12/16] scripts/kallsyms: move ignored symbol types to is_ignored_symbol()

[Masahiro Yamada]

Collect the ignored patterns to is_ignored_symbol().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 63473924d4de..21f4d347f371 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -137,6 +137,21 @@ static bool is_ignored_symbol(const char *name, char type)
 			return true;
 	}
 
+	if (type == 'U' || type == 'u')
+		return true;
+	/* exclude debugging symbols */
+	if (type == 'N' || type == 'n')
+		return true;
+
+	if (toupper(type) == 'A') {
+		/* Keep these useful absolute symbols */
+		if (strcmp(name, "__kernel_syscall_via_break") &&
+		    strcmp(name, "__kernel_syscall_via_epc") &&
+		    strcmp(name, "__kernel_sigtramp") &&
+		    strcmp(name, "__gp"))
+			return true;
+	}
+
 	return false;
 }
 
@@ -188,21 +203,6 @@ static int read_symbol(FILE *in, struct sym_entry *s)
 	else if (check_symbol_range(sym, s->addr, text_ranges,
 				    ARRAY_SIZE(text_ranges)) == 0)
 		/* nothing to do */;
-	else if (toupper(stype) == 'A')
-	{
-		/* Keep these useful absolute symbols */
-		if (strcmp(sym, "__kernel_syscall_via_break") &&
-		    strcmp(sym, "__kernel_syscall_via_epc") &&
-		    strcmp(sym, "__kernel_sigtramp") &&
-		    strcmp(sym, "__gp"))
-			return -1;
-
-	}
-	else if (toupper(stype) == 'U')
-		return -1;
-	/* exclude debugging symbols */
-	else if (stype == 'N' || stype == 'n')
-		return -1;
 
 	/* include the type field in the symbol name, so that it gets
 	 * compressed together */
-- 
2.17.1

[PATCH 13/16] scripts/kallsyms: make check_symbol_range() void function

[Masahiro Yamada]

There is no more reason to check the return value of
check_symbol_range().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 21f4d347f371..144f43363c4d 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -155,8 +155,8 @@ static bool is_ignored_symbol(const char *name, char type)
 	return false;
 }
 
-static int check_symbol_range(const char *sym, unsigned long long addr,
-			      struct addr_range *ranges, int entries)
+static void check_symbol_range(const char *sym, unsigned long long addr,
+			       struct addr_range *ranges, int entries)
 {
 	size_t i;
 	struct addr_range *ar;
@@ -166,14 +166,12 @@ static int check_symbol_range(const char *sym, unsigned long long addr,
 
 		if (strcmp(sym, ar->start_sym) == 0) {
 			ar->start = addr;
-			return 0;
+			return;
 		} else if (strcmp(sym, ar->end_sym) == 0) {
 			ar->end = addr;
-			return 0;
+			return;
 		}
 	}
-
-	return 1;
 }
 
 static int read_symbol(FILE *in, struct sym_entry *s)
@@ -200,9 +198,8 @@ static int read_symbol(FILE *in, struct sym_entry *s)
 	/* Ignore most absolute/undefined (?) symbols. */
 	if (strcmp(sym, "_text") == 0)
 		_text = s->addr;
-	else if (check_symbol_range(sym, s->addr, text_ranges,
-				    ARRAY_SIZE(text_ranges)) == 0)
-		/* nothing to do */;
+
+	check_symbol_range(sym, s->addr, text_ranges, ARRAY_SIZE(text_ranges));
 
 	/* include the type field in the symbol name, so that it gets
 	 * compressed together */
-- 
2.17.1

[PATCH 14/16] scripts/kallsyms: check no valid symbol earlier

[Masahiro Yamada]

insert_real_symbols_in_table() does not touch table_cnt, so the
no valid symbol check can be moved before it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 144f43363c4d..919cb45ce9db 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -608,14 +608,14 @@ static void optimize_token_table(void)
 {
 	build_initial_tok_table();
 
-	insert_real_symbols_in_table();
-
 	/* When valid symbol is not registered, exit to error */
 	if (!table_cnt) {
 		fprintf(stderr, "No valid symbol.\n");
 		exit(1);
 	}
 
+	insert_real_symbols_in_table();
+
 	optimize_result();
 }
 
-- 
2.17.1

[PATCH 15/16] scripts/kallsyms: put check_symbol_range() calls close together

[Masahiro Yamada]

Put the relevant code close together.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 919cb45ce9db..22ff206e2533 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -200,6 +200,7 @@ static int read_symbol(FILE *in, struct sym_entry *s)
 		_text = s->addr;
 
 	check_symbol_range(sym, s->addr, text_ranges, ARRAY_SIZE(text_ranges));
+	check_symbol_range(sym, s->addr, &percpu_range, 1);
 
 	/* include the type field in the symbol name, so that it gets
 	 * compressed together */
@@ -215,9 +216,6 @@ static int read_symbol(FILE *in, struct sym_entry *s)
 
 	s->percpu_absolute = 0;
 
-	/* Record if we've found __per_cpu_start/end. */
-	check_symbol_range(sym, s->addr, &percpu_range, 1);
-
 	return 0;
 }
 
-- 
2.17.1

[PATCH 16/16] scripts/kallsyms: remove redundant initializers

[Masahiro Yamada]

These are set to zero without the explicit initializers.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/kallsyms.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 22ff206e2533..803df71e5069 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -57,9 +57,9 @@ 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 absolute_percpu = 0;
-static int base_relative = 0;
+static int all_symbols;
+static int absolute_percpu;
+static int base_relative;
 
 static int token_profit[0x10000];
 
-- 
2.17.1