From: William Roberts <william.c.robe...@intel.com>

THIS IS WIP...

Rather than using stdio and making copies, just mmap the files
and use the pointers in place. The affect of this change, is that
text file load time is now faster than binary load time by 4.7%
when testing with a file_contexts file from the Android tree. Note
that the Android doesn't use monstrous regexs.

Times are the average of 3 runs.

BEFORE:
Text file allocs: 114803
Text file load time: 0.266101
Bin file allocs: 93073
Bin file load time: 0.248757667

AFTER:
Text file allocs: 103933
Text file load time: 0.236192667
Bin file allocs: 87645
Bin file load time: .247607333

THINGS TO DO:
1. What's arm performance like?
2. What interfaces to backends are busted by this (if any)?
3. Test Android Properties
4. Im pretty sure this breaks sefcontext_compile, fix.
5. Test with PCRE2 enabled.
6. Spell check this message!
7. Run checkpatch

Signed-off-by: William Roberts <william.c.robe...@intel.com>
---
 libselinux/src/label.c                  |   2 -
 libselinux/src/label_android_property.c |  22 ++---
 libselinux/src/label_file.c             | 140 +++++++++++++++++++-------------
 libselinux/src/label_file.h             |  66 +++++++++------
 libselinux/src/label_internal.h         |   3 +-
 libselinux/src/label_support.c          |  79 ++++++++----------
 6 files changed, 172 insertions(+), 140 deletions(-)

diff --git a/libselinux/src/label.c b/libselinux/src/label.c
index 963bfcb..d767b49 100644
--- a/libselinux/src/label.c
+++ b/libselinux/src/label.c
@@ -15,8 +15,6 @@
 #include "callbacks.h"
 #include "label_internal.h"
 
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
-
 typedef int (*selabel_initfunc)(struct selabel_handle *rec,
                                const struct selinux_opt *opts,
                                unsigned nopts);
diff --git a/libselinux/src/label_android_property.c 
b/libselinux/src/label_android_property.c
index 290b438..2aac394 100644
--- a/libselinux/src/label_android_property.c
+++ b/libselinux/src/label_android_property.c
@@ -85,13 +85,19 @@ static int process_line(struct selabel_handle *rec,
                        int pass, unsigned lineno)
 {
        int items;
-       char *prop = NULL, *context = NULL;
+       union {
+               struct {
+                       char *prop;
+                       char *context;
+               };
+               char *array[2];
+       } found = { .array = { 0 } };
        struct saved_data *data = (struct saved_data *)rec->data;
        spec_t *spec_arr = data->spec_arr;
        unsigned int nspec = data->nspec;
        const char *errbuf = NULL;
 
-       items = read_spec_entries(line_buf, &errbuf, 2, &prop, &context);
+       items = read_spec_entries(line_buf, &errbuf, ARRAY_SIZE(found.array), 
found.array);
        if (items < 0) {
                items = errno;
                selinux_log(SELINUX_ERROR,
@@ -108,18 +114,14 @@ static int process_line(struct selabel_handle *rec,
                selinux_log(SELINUX_ERROR,
                            "%s:  line %u is missing fields\n", path,
                            lineno);
-               free(prop);
                errno = EINVAL;
                return -1;
        }
 
-       if (pass == 0) {
-               free(prop);
-               free(context);
-       } else if (pass == 1) {
+       if (pass == 1) {
                /* On the second pass, process and store the specification in 
spec. */
-               spec_arr[nspec].property_key = prop;
-               spec_arr[nspec].lr.ctx_raw = context;
+               spec_arr[nspec].property_key = found.prop;
+               spec_arr[nspec].lr.ctx_raw = found.context;
 
                if (rec->validating) {
                        if (selabel_validate(rec, &spec_arr[nspec].lr) < 0) {
@@ -234,7 +236,7 @@ static void closef(struct selabel_handle *rec)
        for (i = 0; i < data->nspec; i++) {
                spec = &data->spec_arr[i];
                free(spec->property_key);
-               free(spec->lr.ctx_raw);
+               //free(spec->lr.ctx_raw);
                free(spec->lr.ctx_trans);
        }
 
diff --git a/libselinux/src/label_file.c b/libselinux/src/label_file.c
index 7156825..4dc440e 100644
--- a/libselinux/src/label_file.c
+++ b/libselinux/src/label_file.c
@@ -96,43 +96,64 @@ static int nodups_specs(struct saved_data *data, const char 
*path)
        return rc;
 }
 
-static int process_text_file(FILE *fp, const char *prefix,
-                            struct selabel_handle *rec, const char *path)
+static inline struct saved_data *rec_to_data(struct selabel_handle *rec)
+{
+       return (struct saved_data *)rec->data;
+}
+
+static char *mmap_area_get_line(struct mmap_area *area)
+{
+       size_t len = area->next_len;
+       if (!len)
+               return NULL;
+
+       char *start = area->next_addr;
+       char *end = memchr(start, '\n', len);
+
+       /* the file may not end with a newline */
+       if (!end)
+               end = (char *)area->next_addr + len - 1;
+
+       *end = '\0';
+       /* len includes null byte */
+       len = end - start;
+
+       area->next_len -= len + 1;
+       area->next_addr = ++end;
+       return start;
+}
+
+static int process_text_file(const char *path, const char *prefix,
+               struct selabel_handle *rec)
 {
        int rc;
-       size_t line_len;
        unsigned int lineno = 0;
-       char *line_buf = NULL;
+       char *line_buf;
+       struct mmap_area *areas = rec_to_data(rec)->mmap_areas;
+
+       /* mmap_area_get_line() and process_line() require mutable string 
pointers */
+       rc = mprotect(areas->addr, areas->len, PROT_READ | PROT_WRITE);
+       if (rc < 0)
+               goto out;
 
-       while (getline(&line_buf, &line_len, fp) > 0) {
+       while ( (line_buf = mmap_area_get_line(areas)) ) {
                rc = process_line(rec, path, prefix, line_buf, ++lineno);
                if (rc)
                        goto out;
        }
        rc = 0;
 out:
-       free(line_buf);
        return rc;
 }
 
-static int load_mmap(FILE *fp, size_t len, struct selabel_handle *rec,
-                    const char *path)
+static int mmap_file(FILE *fp, size_t len, struct saved_data *data)
 {
-       struct saved_data *data = (struct saved_data *)rec->data;
-       int rc;
-       char *addr, *str_buf;
-       int *stem_map;
-       struct mmap_area *mmap_area;
-       uint32_t i, magic, version;
-       uint32_t entry_len, stem_map_len, regex_array_len;
-       const char *reg_version;
-
-       mmap_area = malloc(sizeof(*mmap_area));
+       struct mmap_area *mmap_area = malloc(sizeof(*mmap_area));
        if (!mmap_area) {
                return -1;
        }
 
-       addr = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fileno(fp), 0);
+       void *addr = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fileno(fp), 0);
        if (addr == MAP_FAILED) {
                free(mmap_area);
                perror("mmap");
@@ -145,17 +166,26 @@ static int load_mmap(FILE *fp, size_t len, struct 
selabel_handle *rec,
        mmap_area->next = data->mmap_areas;
        data->mmap_areas = mmap_area;
 
-       /* check if this looks like an fcontext file */
-       rc = next_entry(&magic, mmap_area, sizeof(uint32_t));
-       if (rc < 0 || magic != SELINUX_MAGIC_COMPILED_FCONTEXT)
-               return -1;
+       return 0;
+}
+
+static int process_binary_file(const char *path, struct selabel_handle *rec)
+{
+       struct saved_data *data = (struct saved_data *)rec->data;
+       int rc;
+       char *str_buf;
+       int *stem_map;
+       struct mmap_area *mmap_area = data->mmap_areas;
+       uint32_t i, version;
+       uint32_t entry_len, stem_map_len, regex_array_len;
+       size_t len;
 
        /* check if this version is higher than we understand */
        rc = next_entry(&version, mmap_area, sizeof(uint32_t));
        if (rc < 0 || version > SELINUX_COMPILED_FCONTEXT_MAX_VERS)
                return -1;
 
-       reg_version = regex_version();
+       const char *reg_version = regex_version();
        if (!reg_version)
                return -1;
 
@@ -235,12 +265,11 @@ static int load_mmap(FILE *fp, size_t len, struct 
selabel_handle *rec,
                /* store the mapping between old and new */
                newid = find_stem(data, buf, stem_len);
                if (newid < 0) {
-                       newid = store_stem(data, buf, stem_len);
+                       newid = store_stem(data, buf, stem_len, true);
                        if (newid < 0) {
                                rc = newid;
                                goto out;
                        }
-                       data->stem_arr[newid].from_mmap = 1;
                }
                stem_map[i] = newid;
        }
@@ -262,7 +291,6 @@ static int load_mmap(FILE *fp, size_t len, struct 
selabel_handle *rec,
                        goto out;
 
                spec = &data->spec_arr[data->nspec];
-               spec->from_mmap = 1;
 
                /* Process context */
                rc = next_entry(&entry_len, mmap_area, sizeof(uint32_t));
@@ -271,22 +299,10 @@ static int load_mmap(FILE *fp, size_t len, struct 
selabel_handle *rec,
                        goto out;
                }
 
-               str_buf = malloc(entry_len);
-               if (!str_buf) {
-                       rc = -1;
-                       goto out;
-               }
-               rc = next_entry(str_buf, mmap_area, entry_len);
+               rc = next_pstr(&spec->lr.ctx_raw, mmap_area, entry_len);
                if (rc < 0)
                        goto out;
 
-               if (str_buf[entry_len - 1] != '\0') {
-                       free(str_buf);
-                       rc = -1;
-                       goto out;
-               }
-               spec->lr.ctx_raw = str_buf;
-
                if (strcmp(spec->lr.ctx_raw, "<<none>>") && rec->validating) {
                        if (selabel_validate(rec, &spec->lr) < 0) {
                                selinux_log(SELINUX_ERROR,
@@ -401,17 +417,29 @@ static char *rolling_append(char *current, const char 
*suffix, size_t max)
        return current;
 }
 
-static bool fcontext_is_binary(FILE *fp)
+static inline int mmap_area_rewind(struct mmap_area *area, size_t bytes)
+{
+       if (area->next_len + bytes > area->len)
+               return -1;
+
+       area->next_addr = (char *) area->next_addr - bytes;
+       area->next_len += bytes;
+       return 0;
+}
+
+static bool fcontext_is_binary(struct mmap_area *area)
 {
        uint32_t magic;
+       bool is_binary = false;
 
-       size_t len = fread(&magic, sizeof(magic), 1, fp);
-       rewind(fp);
+       int rc = next_entry(&magic, area, sizeof(magic));
 
-       return (len && (magic == SELINUX_MAGIC_COMPILED_FCONTEXT));
-}
+       is_binary = (!rc && (magic == SELINUX_MAGIC_COMPILED_FCONTEXT));
+       if (!is_binary)
+               mmap_area_rewind(area, sizeof(magic));
 
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+       return is_binary;
+}
 
 static FILE *open_file(const char *path, const char *suffix,
               char *save_path, size_t len, struct stat *sb, bool open_oldest)
@@ -504,12 +532,17 @@ static int process_file(const char *path, const char 
*suffix,
                if (fp == NULL)
                        return -1;
 
-               rc = fcontext_is_binary(fp) ?
-                               load_mmap(fp, sb.st_size, rec, found_path) :
-                               process_text_file(fp, prefix, rec, found_path);
+               rc = mmap_file(fp, sb.st_size, rec_to_data(rec));
+               if (rc < 0) {
+                       fclose(fp);
+                       return -1;
+               }
+
+               rc = fcontext_is_binary(rec_to_data(rec)->mmap_areas) ?
+                               process_binary_file(found_path, rec) :
+                               process_text_file(found_path, prefix, rec);
                if (!rc)
-                       rc = digest_add_specfile(digest, fp, NULL, sb.st_size,
-                               found_path);
+                       rc = digest_add_specfile(digest, fp, NULL, sb.st_size, 
found_path);
 
                fclose(fp);
 
@@ -613,12 +646,7 @@ static void closef(struct selabel_handle *rec)
        for (i = 0; i < data->nspec; i++) {
                spec = &data->spec_arr[i];
                free(spec->lr.ctx_trans);
-               free(spec->lr.ctx_raw);
                regex_data_free(spec->regex);
-               if (spec->from_mmap)
-                       continue;
-               free(spec->regex_str);
-               free(spec->type_str);
        }
 
        for (i = 0; i < (unsigned int)data->num_stems; i++) {
diff --git a/libselinux/src/label_file.h b/libselinux/src/label_file.h
index 88f4294..2704906 100644
--- a/libselinux/src/label_file.h
+++ b/libselinux/src/label_file.h
@@ -37,7 +37,6 @@ struct spec {
        int matches;            /* number of matching pathnames */
        int stem_id;            /* indicates which stem-compression item */
        char hasMetaChars;      /* regular expression has meta-chars */
-       char from_mmap;         /* this spec is from an mmap of the data */
        size_t prefix_len;      /* length of fixed path prefix */
 };
 
@@ -255,7 +254,7 @@ static inline int find_stem(struct saved_data *data, const 
char *buf,
 }
 
 /* returns the index of the new stored object */
-static inline int store_stem(struct saved_data *data, char *buf, int stem_len)
+static inline int store_stem(struct saved_data *data, char *buf, int stem_len, 
bool from_mmap)
 {
        int num = data->num_stems;
 
@@ -271,7 +270,7 @@ static inline int store_stem(struct saved_data *data, char 
*buf, int stem_len)
        }
        data->stem_arr[num].len = stem_len;
        data->stem_arr[num].buf = buf;
-       data->stem_arr[num].from_mmap = 0;
+       data->stem_arr[num].from_mmap = from_mmap;
        data->num_stems++;
 
        return num;
@@ -298,7 +297,7 @@ static inline int find_stem_from_spec(struct saved_data 
*data, const char *buf)
        if (!stem)
                return -1;
 
-       return store_stem(data, stem, stem_len);
+       return store_stem(data, stem, stem_len, false);
 }
 
 /* This will always check for buffer over-runs and either read the next entry
@@ -317,6 +316,22 @@ static inline int next_entry(void *buf, struct mmap_area 
*fp, size_t bytes)
        return 0;
 }
 
+static inline int next_pstr(char **str, struct mmap_area *fp, size_t len)
+{
+       if (len > fp->next_len)
+               return -1;
+
+       char *tmp = (char *)fp->next_addr;
+       if (tmp[len-1] != '\0')
+               return -1;
+
+       *str = tmp;
+
+       fp->next_addr = (char *)fp->next_addr + len;
+       fp->next_len -= len;
+       return 0;
+}
+
 static inline int compile_regex(struct saved_data *data, struct spec *spec,
                                            const char **errbuf)
 {
@@ -375,13 +390,21 @@ static inline int process_line(struct selabel_handle *rec,
                        char *line_buf, unsigned lineno)
 {
        int items, len, rc;
-       char *regex = NULL, *type = NULL, *context = NULL;
+       union {
+               struct {
+                       char *regex;
+                       char *type;
+                       char *context;
+               };
+               char *array[3];
+       } found = { .array = { 0 } };
+
        struct saved_data *data = (struct saved_data *)rec->data;
        struct spec *spec_arr;
        unsigned int nspec = data->nspec;
        const char *errbuf = NULL;
 
-       items = read_spec_entries(line_buf, &errbuf, 3, &regex, &type, 
&context);
+       items = read_spec_entries(line_buf, &errbuf, ARRAY_SIZE(found.array), 
found.array);
        if (items < 0) {
                rc = errno;
                selinux_log(SELINUX_ERROR,
@@ -398,22 +421,17 @@ static inline int process_line(struct selabel_handle *rec,
                COMPAT_LOG(SELINUX_ERROR,
                            "%s:  line %u is missing fields\n", path,
                            lineno);
-               if (items == 1)
-                       free(regex);
                errno = EINVAL;
                return -1;
        } else if (items == 2) {
                /* The type field is optional. */
-               context = type;
-               type = 0;
+               found.context = found.type;
+               found.type = NULL;
        }
 
-       len = get_stem_from_spec(regex);
-       if (len && prefix && strncmp(prefix, regex, len)) {
+       len = get_stem_from_spec(found.regex);
+       if (len && prefix && strncmp(prefix, found.regex, len)) {
                /* Stem of regex does not match requested prefix, discard. */
-               free(regex);
-               free(type);
-               free(context);
                return 0;
        }
 
@@ -424,13 +442,13 @@ static inline int process_line(struct selabel_handle *rec,
        spec_arr = data->spec_arr;
 
        /* process and store the specification in spec. */
-       spec_arr[nspec].stem_id = find_stem_from_spec(data, regex);
-       spec_arr[nspec].regex_str = regex;
+       spec_arr[nspec].stem_id = find_stem_from_spec(data, found.regex);
+       spec_arr[nspec].regex_str = found.regex;
 
-       spec_arr[nspec].type_str = type;
+       spec_arr[nspec].type_str = found.type;
        spec_arr[nspec].mode = 0;
 
-       spec_arr[nspec].lr.ctx_raw = context;
+       spec_arr[nspec].lr.ctx_raw = found.context;
 
        /*
         * bump data->nspecs to cause closef() to cover it in its free
@@ -442,18 +460,18 @@ static inline int process_line(struct selabel_handle *rec,
                        && compile_regex(data, &spec_arr[nspec], &errbuf)) {
                COMPAT_LOG(SELINUX_ERROR,
                           "%s:  line %u has invalid regex %s:  %s\n",
-                          path, lineno, regex, errbuf);
+                          path, lineno, found.regex, errbuf);
                errno = EINVAL;
                return -1;
        }
 
-       if (type) {
-               mode_t mode = string_to_mode(type);
+       if (found.type) {
+               mode_t mode = string_to_mode(found.type);
 
                if (mode == (mode_t)-1) {
                        COMPAT_LOG(SELINUX_ERROR,
                                   "%s:  line %u has invalid file type %s\n",
-                                  path, lineno, type);
+                                  path, lineno, found.type);
                        errno = EINVAL;
                        return -1;
                }
@@ -464,7 +482,7 @@ static inline int process_line(struct selabel_handle *rec,
         * any meta characters in the RE */
        spec_hasMetaChars(&spec_arr[nspec]);
 
-       if (strcmp(context, "<<none>>") && rec->validating)
+       if (strcmp(found.context, "<<none>>") && rec->validating)
                compat_validate(rec, &spec_arr[nspec].lr, path, lineno);
 
        return 0;
diff --git a/libselinux/src/label_internal.h b/libselinux/src/label_internal.h
index aa48fff..e40d68b 100644
--- a/libselinux/src/label_internal.h
+++ b/libselinux/src/label_internal.h
@@ -136,10 +136,11 @@ compat_validate(struct selabel_handle *rec,
                struct selabel_lookup_rec *contexts,
                const char *path, unsigned lineno) hidden;
 
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 /*
  * The read_spec_entries function may be used to
  * replace sscanf to read entries from spec files.
  */
-extern int read_spec_entries(char *line_buf, const char **errbuf, int 
num_args, ...);
+extern int hidden read_spec_entries(char *line_buf, const char **errbuf, 
unsigned int num, char *found[]);
 
 #endif                         /* _SELABEL_INTERNAL_H_ */
diff --git a/libselinux/src/label_support.c b/libselinux/src/label_support.c
index 26f9ef1..3f5728d 100644
--- a/libselinux/src/label_support.c
+++ b/libselinux/src/label_support.c
@@ -17,39 +17,40 @@
  * Read an entry from a spec file (e.g. file_contexts)
  * entry - Buffer to allocate for the entry.
  * ptr - current location of the line to be processed.
- * returns  - 0 on success and *entry is set to be a null
- *            terminated value. On Error it returns -1 and
- *            errno will be set.
+ * returns  - a pointer to the begining of the string.
+ *            that is the
  *
  */
-static inline int read_spec_entry(char **entry, char **ptr, int *len, const 
char **errbuf)
+static inline char *read_spec_entry(char **current, const char **errbuf)
 {
-       *entry = NULL;
-       char *tmp_buf = NULL;
-
-       while (isspace(**ptr) && **ptr != '\0')
-               (*ptr)++;
+       if(!**current) {
+               (*current)++;
+               return NULL;
+       }
 
-       tmp_buf = *ptr;
-       *len = 0;
+       while (isspace(**current) && **current != '\0')
+               (*current)++;
 
-       while (!isspace(**ptr) && **ptr != '\0') {
-               if (!isascii(**ptr)) {
+       char *start = *current;
+       while (!isspace(**current) && **current != '\0') {
+               if (!isascii(**current)) {
                        errno = EINVAL;
                        *errbuf = "Non-ASCII characters found";
-                       return -1;
+                       return NULL;
                }
-               (*ptr)++;
-               (*len)++;
+               (*current)++;
        }
 
-       if (*len) {
-               *entry = strndup(tmp_buf, *len);
-               if (!*entry)
-                       return -1;
-       }
+       char *end = *current;
 
-       return 0;
+       if (start == end)
+               return NULL;
+
+       if (*end != '\0') {
+               *end = '\0';
+               (*current)++;
+       }
+       return start;
 }
 
 /*
@@ -63,15 +64,13 @@ static inline int read_spec_entry(char **entry, char **ptr, 
int *len, const char
  * This function calls read_spec_entry() to do the actual string processing.
  * As such, can return anything from that function as well.
  */
-int hidden read_spec_entries(char *line_buf, const char **errbuf, int 
num_args, ...)
+int hidden read_spec_entries(char *line_buf, const char **errbuf, unsigned int 
num, char *found[])
 {
-       char **spec_entry, *buf_p;
-       int len, rc, items, entry_len = 0;
-       va_list ap;
-
+       char*buf_p;
+       unsigned int items = 0;
        *errbuf = NULL;
 
-       len = strlen(line_buf);
+       size_t len = strlen(line_buf);
        if (line_buf[len - 1] == '\n')
                line_buf[len - 1] = '\0';
        else
@@ -89,26 +88,12 @@ int hidden read_spec_entries(char *line_buf, const char 
**errbuf, int num_args,
                return 0;
 
        /* Process the spec file entries */
-       va_start(ap, num_args);
-
-       items = 0;
-       while (items < num_args) {
-               spec_entry = va_arg(ap, char **);
-
-               if (len - 1 == buf_p - line_buf) {
-                       va_end(ap);
-                       return items;
-               }
-
-               rc = read_spec_entry(spec_entry, &buf_p, &entry_len, errbuf);
-               if (rc < 0) {
-                       va_end(ap);
-                       return rc;
-               }
-               if (entry_len)
-                       items++;
+       while (items < num) {
+               found[items] = read_spec_entry(&buf_p, errbuf);
+               if (!found[items])
+                       break;
+               items++;
        }
-       va_end(ap);
        return items;
 }
 
-- 
1.9.1

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