tree-wide: assorted fixes/workarounds for supporting musl (#39687)

src/basic/build-path.c

@@ -34,11 +34,11 @@ static int get_runpath_from_dynamic(const ElfW(Dyn) *d, ElfW(Addr) bias, const c
                         break;
 
                 case DT_STRTAB:
-                        /* On MIPS and RISC-V DT_STRTAB records an offset, not a valid address, so it has to be adjusted
-                         * using the bias calculated earlier. */
+                        /* On MIPS, RISC-V, or with musl, DT_STRTAB records an offset, not a valid address,
+                         * so it has to be adjusted using the bias calculated earlier. */
                         if (d->d_un.d_val != 0)
                                 strtab = (const char *) ((uintptr_t) d->d_un.d_val
-#if defined(__mips__) || defined(__riscv)
+#if defined(__mips__) || defined(__riscv) || !defined(__GLIBC__)
                                          + bias
 #endif
                                 );

src/basic/format-util.h

@@ -39,12 +39,18 @@ assert_cc(sizeof(gid_t) == sizeof(uint32_t));
 #  error Unknown timex member size
 #endif
 
-#if SIZEOF_RLIM_T == 8
-#  define RLIM_FMT "%" PRIu64
-#elif SIZEOF_RLIM_T == 4
-#  define RLIM_FMT "%" PRIu32
+#ifdef __GLIBC__
+#  if SIZEOF_RLIM_T == 8
+#    define RLIM_FMT "%" PRIu64
+#  elif SIZEOF_RLIM_T == 4
+#    define RLIM_FMT "%" PRIu32
+#  else
+#    error Unknown rlim_t size
+#  endif
 #else
-#  error Unknown rlim_t size
+/* Assume musl, and it unconditionally uses unsigned long long. */
+assert_cc(SIZEOF_RLIM_T == 8);
+#  define RLIM_FMT "%llu"
 #endif
 
 #if SIZEOF_DEV_T == 8

src/basic/hostname-util.c

@@ -94,8 +94,8 @@ bool hostname_is_valid(const char *s, ValidHostnameFlags flags) {
         if (hyphen)
                 return false;
 
-        if (p-s > HOST_NAME_MAX) /* Note that HOST_NAME_MAX is 64 on Linux, but DNS allows domain names up to
-                                  * 255 characters */
+        /* Note that host name max is 64 on Linux, but DNS allows domain names up to 255 characters. */
+        if (p - s > (ssize_t) LINUX_HOST_NAME_MAX)
                 return false;
 
         return true;
@@ -107,7 +107,7 @@ char* hostname_cleanup(char *s) {
 
         assert(s);
 
-        for (p = s, d = s, dot = hyphen = true; *p && d - s < HOST_NAME_MAX; p++)
+        for (p = s, d = s, dot = hyphen = true; *p && d - s < (ssize_t) LINUX_HOST_NAME_MAX; p++)
                 if (*p == '.') {
                         if (dot || hyphen)
                                 continue;

src/basic/hostname-util.h

@@ -4,6 +4,9 @@
 #include "basic-forward.h"
 #include "strv.h"
 
+/* HOST_NAME_MAX should be 64 on linux, but musl uses the one by POSIX (255). */
+#define LINUX_HOST_NAME_MAX CONST_MIN((size_t) HOST_NAME_MAX, (size_t) 64)
+
 char* get_default_hostname_raw(void);
 
 bool valid_ldh_char(char c) _const_;

src/core/load-fragment.c

@@ -6633,7 +6633,7 @@ int config_parse_protect_hostname(
 
         const char *colon = strchr(rvalue, ':');
         if (colon) {
-                r = unit_full_printf_full(u, colon + 1, HOST_NAME_MAX, &h);
+                r = unit_full_printf_full(u, colon + 1, LINUX_HOST_NAME_MAX, &h);
                 if (r < 0) {
                         log_syntax(unit, LOG_WARNING, filename, line, r,
                                    "Failed to resolve unit specifiers in '%s', ignoring: %m", colon + 1);

src/core/manager.c

@@ -526,8 +526,9 @@ static int manager_setup_signals(Manager *m) {
 
         assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
 
-        /* We make liberal use of realtime signals here. On Linux/glibc we have 30 of them, between
-         * SIGRTMIN+0 ... SIGRTMIN+30 (aka SIGRTMAX). */
+        /* We make liberal use of realtime signals here. On Linux we have 29 of them, between
+         * SIGRTMIN+0 ... SIGRTMIN+29. The glibc has one more (SIGRTMAX is SIGRTMIN+30),
+         * but musl does not (SIGRTMAX is SIGRTMIN+29). */
 
         assert_se(sigemptyset(&mask) == 0);
         sigset_add_many(&mask,
@@ -572,7 +573,7 @@ static int manager_setup_signals(Manager *m) {
                         SIGRTMIN+28, /* systemd: set log target to kmsg */
                         SIGRTMIN+29, /* systemd: set log target to syslog-or-kmsg (obsolete) */
 
-                        /* ... one free signal here SIGRTMIN+30 ... */
+                        /* ... one free signal here SIGRTMIN+30 (glibc only) ... */
                         -1);
         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 

src/libsystemd-network/sd-lldp-tx.c

@@ -186,12 +186,8 @@ int sd_lldp_tx_set_hostname(sd_lldp_tx *lldp_tx, const char *hostname) {
         assert_return(lldp_tx, -EINVAL);
 
         /* An empty string unset the previously set hostname. */
-        if (!isempty(hostname)) {
-                assert_cc(HOST_NAME_MAX < 512);
-
-                if (!hostname_is_valid(hostname, 0))
-                        return -EINVAL;
-        }
+        if (!isempty(hostname) && !hostname_is_valid(hostname, /* flags= */ 0))
+                return -EINVAL;
 
         return free_and_strdup(&lldp_tx->hostname, empty_to_null(hostname));
 }

src/shared/cpu-set-util.c

@@ -96,9 +96,11 @@ char* cpu_set_to_mask_string(const CPUSet *c) {
         for (size_t i = c->allocated * 8; i > 0; ) {
                 uint32_t m = 0;
 
-                for (int j = (i % 32 ?: 32) - 1; j >= 0; j--)
-                        if (CPU_ISSET_S(--i, c->allocated, c->set))
+                for (int j = (i % 32 ?: 32) - 1; j >= 0; j--) {
+                        --i;
+                        if (CPU_ISSET_S(i, c->allocated, c->set))
                                 SET_BIT(m, j);
+                }
 
                 if (!found_nonzero) {
                         if (m == 0)

src/shared/hostname-setup.c

@@ -51,7 +51,7 @@ int sethostname_idempotent(const char *s) {
 int shorten_overlong(const char *s, char **ret) {
         _cleanup_free_ char *h = NULL;
 
-        /* Shorten an overlong name to HOST_NAME_MAX or to the first dot,
+        /* Shorten an overlong name to LINUX_HOST_NAME_MAX or to the first dot,
          * whatever comes earlier. */
 
         assert(s);
@@ -70,7 +70,7 @@ int shorten_overlong(const char *s, char **ret) {
         if (p)
                 *p = 0;
 
-        strshorten(h, HOST_NAME_MAX);
+        strshorten(h, LINUX_HOST_NAME_MAX);
 
         if (!hostname_is_valid(h, /* flags= */ 0))
                 return -EDOM;
@@ -403,7 +403,7 @@ int pidref_gethostname_full(PidRef *pidref, GetHostnameFlags flags, char **ret)
         if (r < 0)
                 return r;
 
-        char buf[HOST_NAME_MAX+1];
+        char buf[LINUX_HOST_NAME_MAX+1];
         ssize_t n = loop_read(result_pipe[0], buf, sizeof(buf), /* do_poll = */ false);
         if (n < 0)
                 return n;

src/test/test-signal-util.c

@@ -13,8 +13,9 @@ TEST(rt_signals) {
         info(SIGRTMIN);
         info(SIGRTMAX);
 
-        /* We use signals SIGRTMIN+0 to SIGRTMIN+30 unconditionally */
-        assert_se(SIGRTMAX - SIGRTMIN >= 30);
+        /* We use signals SIGRTMIN+0 to SIGRTMIN+29 unconditionally. SIGRTMIN+30 can be used only when
+         * built with glibc. */
+        assert_se(SIGRTMAX - SIGRTMIN >= 29);
 }
 
 static void test_signal_to_string_one(int val) {