From: Yu Watanabe Date: Thu, 9 Jul 2026 02:17:56 +0000 (+0900) Subject: compress: split compress_blob() and friends to minimize dlopen dependencies X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=05bdf4bfa9193e91532c52798a2ffc3fd8a3700c;p=thirdparty%2Fsystemd.git compress: split compress_blob() and friends to minimize dlopen dependencies Previously, even though sd-journal does not support bzip2 and gzip compression, the dlopen ELF notes for those libraries were still being attached to libsystemd.so and various journal-handling executables. This occurred because the unified compression/decompression interfaces handled all formats unconditionally, causing the compiler and linker to pull in all associated dlopen notes across the board. To resolve this, split these functions into generic and journal-specific variants (e.g., introducing compress_blob_journal() and decompress_blob_journal()). The journal-specific variants only handle formats actually supported by the journal (LZ4, XZ, and ZSTD). By updating sd-journal, journald, journalctl, and related utilities to use these new `_journal` interfaces and switching them to the narrower COMPRESS_JOURNAL_NOTE macro, we ensure that unnecessary dlopen notes (for bzip2 and gzip) are no longer embedded into these binaries. --- diff --git a/src/basic/compress.c b/src/basic/compress.c index 5936a13f8e8..2bc11f48bc2 100644 --- a/src/basic/compress.c +++ b/src/basic/compress.c @@ -254,6 +254,19 @@ Compression compression_from_filename(const char *filename) { return c; } +bool compression_supported_journal(Compression c) { + static const unsigned supported = + (1U << COMPRESSION_NONE) | + (1U << COMPRESSION_XZ) * HAVE_XZ | + (1U << COMPRESSION_LZ4) * HAVE_LZ4 | + (1U << COMPRESSION_ZSTD) * HAVE_ZSTD; + + assert(c >= 0); + assert(c < _COMPRESSION_MAX); + + return BIT_SET(supported, c); +} + bool compression_supported(Compression c) { static const unsigned supported = (1U << COMPRESSION_NONE) | @@ -639,7 +652,7 @@ static int compress_blob_bzip2( #endif } -int compress_blob( +int compress_blob_journal( Compression compression, const void *src, uint64_t src_size, void *dst, size_t dst_alloc_size, size_t *dst_size, int level) { @@ -651,12 +664,23 @@ int compress_blob( return compress_blob_lz4(src, src_size, dst, dst_alloc_size, dst_size, level); case COMPRESSION_ZSTD: return compress_blob_zstd(src, src_size, dst, dst_alloc_size, dst_size, level); + default: + return -EOPNOTSUPP; + } +} + +int compress_blob( + Compression compression, + const void *src, uint64_t src_size, + void *dst, size_t dst_alloc_size, size_t *dst_size, int level) { + + switch (compression) { case COMPRESSION_GZIP: return compress_blob_gzip(src, src_size, dst, dst_alloc_size, dst_size, level); case COMPRESSION_BZIP2: return compress_blob_bzip2(src, src_size, dst, dst_alloc_size, dst_size, level); default: - return -EOPNOTSUPP; + return compress_blob_journal(compression, src, src_size, dst, dst_alloc_size, dst_size, level); } } @@ -1033,7 +1057,7 @@ static int decompress_blob_bzip2( #endif } -int decompress_blob( +int decompress_blob_journal( Compression compression, const void *src, uint64_t src_size, @@ -1054,6 +1078,20 @@ int decompress_blob( return decompress_blob_zstd( src, src_size, dst, dst_size, dst_max); + default: + return -EPROTONOSUPPORT; + } +} + +int decompress_blob( + Compression compression, + const void *src, + uint64_t src_size, + void **dst, + size_t *dst_size, + size_t dst_max) { + + switch (compression) { case COMPRESSION_GZIP: return decompress_blob_gzip( src, src_size, @@ -1063,7 +1101,10 @@ int decompress_blob( src, src_size, dst, dst_size, dst_max); default: - return -EPROTONOSUPPORT; + return decompress_blob_journal( + compression, + src, src_size, + dst, dst_size, dst_max); } } @@ -1452,7 +1493,7 @@ static int decompress_startswith_bzip2( #endif } -int decompress_startswith( +int decompress_startswith_journal( Compression compression, const void *src, uint64_t src_size, void **buffer, @@ -1466,12 +1507,25 @@ int decompress_startswith( return decompress_startswith_lz4(src, src_size, buffer, prefix, prefix_len, extra); case COMPRESSION_ZSTD: return decompress_startswith_zstd(src, src_size, buffer, prefix, prefix_len, extra); + default: + return -EOPNOTSUPP; + } +} + +int decompress_startswith( + Compression compression, + const void *src, uint64_t src_size, + void **buffer, + const void *prefix, size_t prefix_len, + uint8_t extra) { + + switch (compression) { case COMPRESSION_GZIP: return decompress_startswith_gzip(src, src_size, buffer, prefix, prefix_len, extra); case COMPRESSION_BZIP2: return decompress_startswith_bzip2(src, src_size, buffer, prefix, prefix_len, extra); default: - return -EOPNOTSUPP; + return decompress_startswith_journal(compression, src, src_size, buffer, prefix, prefix_len, extra); } } diff --git a/src/basic/compress.h b/src/basic/compress.h index 52fdf3aa272..e25ab6d9a42 100644 --- a/src/basic/compress.h +++ b/src/basic/compress.h @@ -27,6 +27,7 @@ Compression compression_from_string_harder(const char *s); * filename does not carry a recognized compression suffix. */ Compression compression_from_filename(const char *filename); +bool compression_supported_journal(Compression c); bool compression_supported(Compression c); /* Buffer size used by streaming compression APIs and pipeline stages that feed into them. Sized to @@ -59,9 +60,17 @@ Compression compressor_type(const Compressor *c); /* Blob compression/decompression */ +int compress_blob_journal( + Compression compression, + const void *src, uint64_t src_size, + void *dst, size_t dst_alloc_size, size_t *dst_size, int level); int compress_blob(Compression compression, const void *src, uint64_t src_size, void *dst, size_t dst_alloc_size, size_t *dst_size, int level); +int decompress_blob_journal( + Compression compression, + const void *src, uint64_t src_size, + void **dst, size_t *dst_size, size_t dst_max); int decompress_blob(Compression compression, const void *src, uint64_t src_size, void **dst, size_t *dst_size, size_t dst_max); @@ -69,6 +78,12 @@ int decompress_blob(Compression compression, int decompress_zlib_raw(const void *src, uint64_t src_size, void *dst, size_t dst_size, int wbits); +int decompress_startswith_journal( + Compression compression, + const void *src, uint64_t src_size, + void **buffer, + const void *prefix, size_t prefix_len, + uint8_t extra); int decompress_startswith(Compression compression, const void *src, uint64_t src_size, void **buffer, diff --git a/src/basic/dlopen-note.h b/src/basic/dlopen-note.h index 41661939a1f..6d3bd5e2bc9 100644 --- a/src/basic/dlopen-note.h +++ b/src/basic/dlopen-note.h @@ -94,8 +94,11 @@ LIBZSTD_NOTE(priority) #define COMPRESS_DEFAULT_NOTE \ + COMPRESS_JOURNAL_NOTE; \ LIBBZ2_NOTE(suggested); \ + LIBZ_NOTE(suggested) + +#define COMPRESS_JOURNAL_NOTE \ LIBLZ4_NOTE(COMPRESSION_PRIORITY_LZ4); \ LIBLZMA_NOTE(COMPRESSION_PRIORITY_XZ); \ - LIBZ_NOTE(suggested); \ LIBZSTD_NOTE(COMPRESSION_PRIORITY_ZSTD) diff --git a/src/journal-remote/journal-gatewayd.c b/src/journal-remote/journal-gatewayd.c index 9def4a3bc9f..8a6e59c8d76 100644 --- a/src/journal-remote/journal-gatewayd.c +++ b/src/journal-remote/journal-gatewayd.c @@ -1259,7 +1259,7 @@ static int run(int argc, char *argv[]) { MHD_USE_THREAD_PER_CONNECTION; int r, n; - COMPRESS_DEFAULT_NOTE; + COMPRESS_JOURNAL_NOTE; LIBGNUTLS_NOTE(suggested); log_setup(); diff --git a/src/journal/bsod.c b/src/journal/bsod.c index 9a9067088c0..78093844fa6 100644 --- a/src/journal/bsod.c +++ b/src/journal/bsod.c @@ -288,7 +288,7 @@ static int run(int argc, char *argv[]) { _cleanup_free_ char *message = NULL; int r; - COMPRESS_DEFAULT_NOTE; + COMPRESS_JOURNAL_NOTE; LIBQRENCODE_NOTE(suggested); log_setup(); diff --git a/src/journal/journalctl.c b/src/journal/journalctl.c index bb5b376a933..b407a77d970 100644 --- a/src/journal/journalctl.c +++ b/src/journal/journalctl.c @@ -1022,7 +1022,7 @@ static int run(int argc, char *argv[]) { _cleanup_strv_free_ char **args = NULL; int r; - COMPRESS_DEFAULT_NOTE; + COMPRESS_JOURNAL_NOTE; LIBACL_NOTE(recommended); LIBBLKID_NOTE(recommended); LIBCRYPTSETUP_NOTE(suggested); diff --git a/src/journal/journald.c b/src/journal/journald.c index 3cab48f6b7b..ec095684df0 100644 --- a/src/journal/journald.c +++ b/src/journal/journald.c @@ -26,7 +26,7 @@ static int run(int argc, char *argv[]) { LogTarget log_target; int r; - COMPRESS_DEFAULT_NOTE; + COMPRESS_JOURNAL_NOTE; LIBACL_NOTE(recommended); LIBCRYPTO_NOTE(suggested); LIBPCRE2_NOTE(suggested); diff --git a/src/libsystemd/sd-journal/journal-file.c b/src/libsystemd/sd-journal/journal-file.c index 93b2c90c152..b0df06d75aa 100644 --- a/src/libsystemd/sd-journal/journal-file.c +++ b/src/libsystemd/sd-journal/journal-file.c @@ -365,7 +365,7 @@ static Compression getenv_compression(void) { return DEFAULT_COMPRESSION; } - if (!compression_supported(c)) { + if (!compression_supported_journal(c)) { log_debug("Unsupported compression algorithm specified, ignoring: %s", e); return DEFAULT_COMPRESSION; } @@ -1861,7 +1861,7 @@ static int maybe_compress_payload( return 0; } - r = compress_blob(c, src, size, dst, size - 1, rsize, /* level= */ -1); + r = compress_blob_journal(c, src, size, dst, size - 1, rsize, /* level= */ -1); if (r < 0) return log_debug_errno(r, "Failed to compress data object using %s, ignoring: %m", compression_to_string(c)); @@ -1983,7 +1983,7 @@ static int maybe_decompress_payload( int r; if (field) { - r = decompress_startswith(compression, payload, size, &f->compress_buffer, field, + r = decompress_startswith_journal(compression, payload, size, &f->compress_buffer, field, field_length, '='); if (r < 0) return log_debug_errno(r, @@ -2003,7 +2003,7 @@ static int maybe_decompress_payload( return 1; } - r = decompress_blob(compression, payload, size, &f->compress_buffer, &rsize, DATA_SIZE_MAX); + r = decompress_blob_journal(compression, payload, size, &f->compress_buffer, &rsize, DATA_SIZE_MAX); if (r < 0) return r; diff --git a/src/libsystemd/sd-journal/journal-verify.c b/src/libsystemd/sd-journal/journal-verify.c index d214a68e686..79061940b39 100644 --- a/src/libsystemd/sd-journal/journal-verify.c +++ b/src/libsystemd/sd-journal/journal-verify.c @@ -125,7 +125,7 @@ static int hash_payload(JournalFile *f, Object *o, uint64_t offset, const uint8_ _cleanup_free_ void *b = NULL; size_t b_size; - r = decompress_blob(c, src, size, &b, &b_size, DATA_SIZE_MAX); + r = decompress_blob_journal(c, src, size, &b, &b_size, DATA_SIZE_MAX); if (r < 0) { error_errno(offset, r, "%s decompression failed: %m", compression_to_string(c)); diff --git a/src/login/loginctl.c b/src/login/loginctl.c index be670254211..566f4db877d 100644 --- a/src/login/loginctl.c +++ b/src/login/loginctl.c @@ -1662,7 +1662,7 @@ static int run(int argc, char *argv[]) { char **args = NULL; int r; - COMPRESS_DEFAULT_NOTE; + COMPRESS_JOURNAL_NOTE; setlocale(LC_ALL, ""); log_setup(); diff --git a/src/machine/machinectl.c b/src/machine/machinectl.c index dc2381fc84a..19ad3857339 100644 --- a/src/machine/machinectl.c +++ b/src/machine/machinectl.c @@ -2635,7 +2635,7 @@ static int run(int argc, char *argv[]) { _cleanup_strv_free_ char **args = NULL; int r; - COMPRESS_DEFAULT_NOTE; + COMPRESS_JOURNAL_NOTE; LIBSELINUX_NOTE(recommended); setlocale(LC_ALL, ""); diff --git a/src/network/networkctl.c b/src/network/networkctl.c index f85c74b6afa..f7a6e6eef76 100644 --- a/src/network/networkctl.c +++ b/src/network/networkctl.c @@ -209,7 +209,7 @@ static int run(int argc, char* argv[]) { char **args = NULL; int r; - COMPRESS_DEFAULT_NOTE; + COMPRESS_JOURNAL_NOTE; LIBSELINUX_NOTE(recommended); log_setup();