forked from rpms/glibc
210 lines
7.6 KiB
Diff
210 lines
7.6 KiB
Diff
commit 73b6e50a22dea9ae6144beaaa675d2ac62c281ca
|
|
Author: Florian Weimer <fweimer@redhat.com>
|
|
Date: Fri Dec 4 09:13:43 2020 +0100
|
|
|
|
elf: Implement tail merging of strings in ldconfig
|
|
|
|
This simplifies the string table construction in elf/cache.c
|
|
because there is no more need to keep track of offsets explicitly;
|
|
the string table implementation does this internally.
|
|
|
|
This change slightly reduces the size of the cache on disk. The
|
|
file format does not change as a result. The strings are
|
|
null-terminated, without explicit length, so tail merging is
|
|
transparent to readers.
|
|
|
|
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
|
|
|
|
diff --git a/elf/Makefile b/elf/Makefile
|
|
index abb3e9d1179ef5cd..a3e802a9a99b759c 100644
|
|
--- a/elf/Makefile
|
|
+++ b/elf/Makefile
|
|
@@ -112,7 +112,8 @@ others-static += ldconfig
|
|
others += ldconfig
|
|
install-rootsbin += ldconfig
|
|
|
|
-ldconfig-modules := cache readlib xmalloc xstrdup chroot_canon static-stubs
|
|
+ldconfig-modules := cache readlib xmalloc xstrdup chroot_canon static-stubs \
|
|
+ stringtable
|
|
extra-objs += $(ldconfig-modules:=.o)
|
|
others-extras = $(ldconfig-modules)
|
|
endif
|
|
diff --git a/elf/cache.c b/elf/cache.c
|
|
index 5a8f1ad70cc3fead..f773cacacf26db1c 100644
|
|
--- a/elf/cache.c
|
|
+++ b/elf/cache.c
|
|
@@ -35,11 +35,15 @@
|
|
#include <ldconfig.h>
|
|
#include <dl-cache.h>
|
|
#include <version.h>
|
|
+#include <stringtable.h>
|
|
+
|
|
+/* Used to store library names, paths, and other strings. */
|
|
+static struct stringtable strings;
|
|
|
|
struct cache_entry
|
|
{
|
|
- char *lib; /* Library name. */
|
|
- char *path; /* Path to find library. */
|
|
+ struct stringtable_entry *lib; /* Library name. */
|
|
+ struct stringtable_entry *path; /* Path to find library. */
|
|
int flags; /* Flags to indicate kind of library. */
|
|
unsigned int osversion; /* Required OS version. */
|
|
uint64_t hwcap; /* Important hardware capabilities. */
|
|
@@ -300,7 +304,7 @@ static int
|
|
compare (const struct cache_entry *e1, const struct cache_entry *e2)
|
|
{
|
|
/* We need to swap entries here to get the correct sort order. */
|
|
- int res = _dl_cache_libcmp (e2->lib, e1->lib);
|
|
+ int res = _dl_cache_libcmp (e2->lib->string, e1->lib->string);
|
|
if (res == 0)
|
|
{
|
|
if (e1->flags < e2->flags)
|
|
@@ -369,26 +373,24 @@ save_cache (const char *cache_name)
|
|
{
|
|
/* The cache entries are sorted already, save them in this order. */
|
|
|
|
- /* Count the length of all strings. */
|
|
- /* The old format doesn't contain hwcap entries and doesn't contain
|
|
- libraries in subdirectories with hwcaps entries. Count therefore
|
|
- also all entries with hwcap == 0. */
|
|
- size_t total_strlen = 0;
|
|
struct cache_entry *entry;
|
|
/* Number of cache entries. */
|
|
int cache_entry_count = 0;
|
|
- /* Number of normal cache entries. */
|
|
+ /* The old format doesn't contain hwcap entries and doesn't contain
|
|
+ libraries in subdirectories with hwcaps entries. Count therefore
|
|
+ also all entries with hwcap == 0. */
|
|
int cache_entry_old_count = 0;
|
|
|
|
for (entry = entries; entry != NULL; entry = entry->next)
|
|
{
|
|
- /* Account the final NULs. */
|
|
- total_strlen += strlen (entry->lib) + strlen (entry->path) + 2;
|
|
++cache_entry_count;
|
|
if (entry->hwcap == 0)
|
|
++cache_entry_old_count;
|
|
}
|
|
|
|
+ struct stringtable_finalized strings_finalized;
|
|
+ stringtable_finalize (&strings, &strings_finalized);
|
|
+
|
|
/* Create the on disk cache structure. */
|
|
struct cache_file *file_entries = NULL;
|
|
size_t file_entries_size = 0;
|
|
@@ -432,7 +434,7 @@ save_cache (const char *cache_name)
|
|
sizeof CACHE_VERSION - 1);
|
|
|
|
file_entries_new->nlibs = cache_entry_count;
|
|
- file_entries_new->len_strings = total_strlen;
|
|
+ file_entries_new->len_strings = strings_finalized.size;
|
|
file_entries_new->flags = cache_file_new_flags_endian_current;
|
|
}
|
|
|
|
@@ -449,20 +451,20 @@ save_cache (const char *cache_name)
|
|
str_offset = 0;
|
|
|
|
/* An array for all strings. */
|
|
- char *strings = xmalloc (total_strlen);
|
|
- char *str = strings;
|
|
int idx_old;
|
|
int idx_new;
|
|
|
|
for (idx_old = 0, idx_new = 0, entry = entries; entry != NULL;
|
|
entry = entry->next, ++idx_new)
|
|
{
|
|
- /* First the library. */
|
|
if (opt_format != opt_format_new && entry->hwcap == 0)
|
|
{
|
|
file_entries->libs[idx_old].flags = entry->flags;
|
|
/* XXX: Actually we can optimize here and remove duplicates. */
|
|
file_entries->libs[idx_old].key = str_offset + pad;
|
|
+ file_entries->libs[idx_new].key = str_offset + entry->lib->offset;
|
|
+ file_entries->libs[idx_new].value
|
|
+ = str_offset + entry->path->offset;
|
|
}
|
|
if (opt_format != opt_format_old)
|
|
{
|
|
@@ -473,20 +475,12 @@ save_cache (const char *cache_name)
|
|
file_entries_new->libs[idx_new].flags = entry->flags;
|
|
file_entries_new->libs[idx_new].osversion = entry->osversion;
|
|
file_entries_new->libs[idx_new].hwcap = entry->hwcap;
|
|
- file_entries_new->libs[idx_new].key = str_offset;
|
|
+ file_entries_new->libs[idx_new].key
|
|
+ = str_offset + entry->lib->offset;
|
|
+ file_entries_new->libs[idx_new].value
|
|
+ = str_offset + entry->path->offset;
|
|
}
|
|
|
|
- size_t len = strlen (entry->lib) + 1;
|
|
- str = mempcpy (str, entry->lib, len);
|
|
- str_offset += len;
|
|
- /* Then the path. */
|
|
- if (opt_format != opt_format_new && entry->hwcap == 0)
|
|
- file_entries->libs[idx_old].value = str_offset + pad;
|
|
- if (opt_format != opt_format_old)
|
|
- file_entries_new->libs[idx_new].value = str_offset;
|
|
- len = strlen (entry->path) + 1;
|
|
- str = mempcpy (str, entry->path, len);
|
|
- str_offset += len;
|
|
/* Ignore entries with hwcap for old format. */
|
|
if (entry->hwcap == 0)
|
|
++idx_old;
|
|
@@ -511,7 +505,7 @@ save_cache (const char *cache_name)
|
|
extension_offset += pad;
|
|
extension_offset += file_entries_new_size;
|
|
}
|
|
- extension_offset += total_strlen;
|
|
+ extension_offset += strings_finalized.size;
|
|
extension_offset = roundup (extension_offset, 4); /* Provide alignment. */
|
|
if (opt_format != opt_format_old)
|
|
file_entries_new->extension_offset = extension_offset;
|
|
@@ -551,7 +545,8 @@ save_cache (const char *cache_name)
|
|
error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
|
|
}
|
|
|
|
- if (write (fd, strings, total_strlen) != (ssize_t) total_strlen)
|
|
+ if (write (fd, strings_finalized.strings, strings_finalized.size)
|
|
+ != (ssize_t) strings_finalized.size)
|
|
error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
|
|
|
|
if (opt_format != opt_format_old)
|
|
@@ -580,7 +575,7 @@ save_cache (const char *cache_name)
|
|
/* Free all allocated memory. */
|
|
free (file_entries_new);
|
|
free (file_entries);
|
|
- free (strings);
|
|
+ free (strings_finalized.strings);
|
|
|
|
while (entries)
|
|
{
|
|
@@ -596,14 +591,19 @@ void
|
|
add_to_cache (const char *path, const char *lib, int flags,
|
|
unsigned int osversion, uint64_t hwcap)
|
|
{
|
|
- size_t liblen = strlen (lib) + 1;
|
|
- size_t len = liblen + strlen (path) + 1;
|
|
- struct cache_entry *new_entry
|
|
- = xmalloc (sizeof (struct cache_entry) + liblen + len);
|
|
-
|
|
- new_entry->lib = memcpy ((char *) (new_entry + 1), lib, liblen);
|
|
- new_entry->path = new_entry->lib + liblen;
|
|
- snprintf (new_entry->path, len, "%s/%s", path, lib);
|
|
+ struct cache_entry *new_entry = xmalloc (sizeof (*new_entry));
|
|
+
|
|
+ struct stringtable_entry *path_interned;
|
|
+ {
|
|
+ char *p;
|
|
+ if (asprintf (&p, "%s/%s", path, lib) < 0)
|
|
+ error (EXIT_FAILURE, errno, _("Could not create library path"));
|
|
+ path_interned = stringtable_add (&strings, p);
|
|
+ free (p);
|
|
+ }
|
|
+
|
|
+ new_entry->lib = stringtable_add (&strings, lib);
|
|
+ new_entry->path = path_interned;
|
|
new_entry->flags = flags;
|
|
new_entry->osversion = osversion;
|
|
new_entry->hwcap = hwcap;
|