Merge tag 'pull-lu-20241105' of https://gitlab.com/rth7680/qemu into staging

tests/tcg: Replace -mpower8-vector with -mcpu=power8
linux-user: Fix GDB complaining about system-supplied DSO string table index
linux-user: Allow custom rt signal mappings

# -----BEGIN PGP SIGNATURE-----
#
# iQFRBAABCgA7FiEEekgeeIaLTbaoWgXAZN846K9+IV8FAmcqM2wdHHJpY2hhcmQu
# aGVuZGVyc29uQGxpbmFyby5vcmcACgkQZN846K9+IV86KQgAhR1OmVAhPYTJiYH6
# Bhp9s+PbdFw/UbxConf9+WFoa/vM1x/QvX1ybzNDl9aOeiH9RIX4hFWUH5WR8xu+
# gZrzplHDcsrUEs5Q7/GWGJaCbd92Rn6g5wcXyoVebMaVP1g/m+NJoxo2XOpZvY06
# G0BcNj4Ib/D0FgkgZrUJcf3DBWaW/9WCd17fBXLo1bpahdKvqV4PbmhhH+QZCVXr
# GHg03F+/35U85kNVnPcUg4PJARQHdK4ZmfE4etgGvVkTdS8r43qfO1nMT0ul8aOD
# uATdMQrbwKA0XLjWVOVxe4165c+luHpUweKNgiOie+s849YUM3TsFpunKoPBIEpQ
# Gu0ejw==
# =wipF
# -----END PGP SIGNATURE-----
# gpg: Signature made Tue 05 Nov 2024 15:02:04 GMT
# gpg:                using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg:                issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* tag 'pull-lu-20241105' of https://gitlab.com/rth7680/qemu:
  tests/tcg: Add SIGRTMIN/SIGRTMAX test
  linux-user: Allow custom rt signal mappings
  linux-user: Fix GDB complaining about system-supplied DSO string table index
  tests/tcg: Replace -mpower8-vector with -mcpu=power8

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

5 files changed, 187 insertions, 73 deletions

diff --git a/linux-user/gen-vdso-elfn.c.inc b/linux-user/gen-vdso-elfn.c.inc
index 95856eb839..b47019e136 100644
--- a/linux-user/gen-vdso-elfn.c.inc
+++ b/linux-user/gen-vdso-elfn.c.inc
@@ -68,28 +68,45 @@ static void elfN(search_symtab)(ElfN(Shdr) *shdr, unsigned sym_idx,
                                 void *buf, bool need_bswap)
 {
     unsigned str_idx = shdr[sym_idx].sh_link;
-    ElfN(Sym) *sym = buf + shdr[sym_idx].sh_offset;
-    unsigned sym_n = shdr[sym_idx].sh_size / sizeof(*sym);
+    ElfN(Sym) *target_sym = buf + shdr[sym_idx].sh_offset;
+    unsigned sym_n = shdr[sym_idx].sh_size / sizeof(*target_sym);
     const char *str = buf + shdr[str_idx].sh_offset;
 
     for (unsigned i = 0; i < sym_n; ++i) {
         const char *name;
+        ElfN(Sym) sym;
 
+        memcpy(&sym, &target_sym[i], sizeof(sym));
         if (need_bswap) {
-            elfN(bswap_sym)(sym + i);
+            elfN(bswap_sym)(&sym);
         }
-        name = str + sym[i].st_name;
+        name = str + sym.st_name;
 
         if (sigreturn_sym && strcmp(sigreturn_sym, name) == 0) {
-            sigreturn_addr = sym[i].st_value;
+            sigreturn_addr = sym.st_value;
         }
         if (rt_sigreturn_sym && strcmp(rt_sigreturn_sym, name) == 0) {
-            rt_sigreturn_addr = sym[i].st_value;
+            rt_sigreturn_addr = sym.st_value;
         }
     }
 }
 
-static void elfN(process)(FILE *outf, void *buf, bool need_bswap)
+static void elfN(bswap_ps_hdrs)(ElfN(Ehdr) *ehdr)
+{
+    ElfN(Phdr) *phdr = (void *)ehdr + ehdr->e_phoff;
+    ElfN(Shdr) *shdr = (void *)ehdr + ehdr->e_shoff;
+    ElfN(Half) i;
+
+    for (i = 0; i < ehdr->e_phnum; ++i) {
+        elfN(bswap_phdr)(&phdr[i]);
+    }
+
+    for (i = 0; i < ehdr->e_shnum; ++i) {
+        elfN(bswap_shdr)(&shdr[i]);
+    }
+}
+
+static void elfN(process)(FILE *outf, void *buf, long len, bool need_bswap)
 {
     ElfN(Ehdr) *ehdr = buf;
     ElfN(Phdr) *phdr;
@@ -103,24 +120,14 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap)
     int errors = 0;
 
     if (need_bswap) {
-        elfN(bswap_ehdr)(ehdr);
+        elfN(bswap_ehdr)(buf);
+        elfN(bswap_ps_hdrs)(buf);
     }
 
     phnum = ehdr->e_phnum;
     phdr = buf + ehdr->e_phoff;
-    if (need_bswap) {
-        for (unsigned i = 0; i < phnum; ++i) {
-            elfN(bswap_phdr)(phdr + i);
-        }
-    }
-
     shnum = ehdr->e_shnum;
     shdr = buf + ehdr->e_shoff;
-    if (need_bswap) {
-        for (unsigned i = 0; i < shnum; ++i) {
-            elfN(bswap_shdr)(shdr + i);
-        }
-    }
     for (unsigned i = 0; i < shnum; ++i) {
         switch (shdr[i].sh_type) {
         case SHT_SYMTAB:
@@ -154,7 +161,24 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap)
             fprintf(stderr, "LOAD segment not loaded at address 0\n");
             errors++;
         }
-        first_segsz = phdr[i].p_filesz;
+        /*
+         * Extend the program header to cover the entire VDSO, so that
+         * load_elf_vdso() loads everything, including section headers.
+         *
+         * Require that there is no .bss, since it would break this
+         * approach.
+         */
+        if (phdr[i].p_filesz != phdr[i].p_memsz) {
+            fprintf(stderr, "LOAD segment's filesz and memsz differ\n");
+            errors++;
+        }
+        if (phdr[i].p_filesz > len) {
+            fprintf(stderr, "LOAD segment is larger than the whole VDSO\n");
+            errors++;
+        }
+        phdr[i].p_filesz = len;
+        phdr[i].p_memsz = len;
+        first_segsz = len;
         if (first_segsz < ehdr->e_phoff + phnum * sizeof(*phdr)) {
             fprintf(stderr, "LOAD segment does not cover PHDRs\n");
             errors++;
@@ -197,17 +221,24 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap)
         output_reloc(outf, buf, &phdr[i].p_paddr);
     }
 
+    /* Relocate the section headers. */
+    for (unsigned i = 0; i < shnum; ++i) {
+        output_reloc(outf, buf, &shdr[i].sh_addr);
+    }
+
     /* Relocate the DYNAMIC entries. */
     if (dynamic_addr) {
-        ElfN(Dyn) *dyn = buf + dynamic_ofs;
-        __typeof(dyn->d_tag) tag;
+        ElfN(Dyn) *target_dyn = buf + dynamic_ofs;
+        __typeof(((ElfN(Dyn) *)target_dyn)->d_tag) tag;
 
         do {
+            ElfN(Dyn) dyn;
 
+            memcpy(&dyn, target_dyn, sizeof(dyn));
             if (need_bswap) {
-                elfN(bswap_dyn)(dyn);
+                elfN(bswap_dyn)(&dyn);
             }
-            tag = dyn->d_tag;
+            tag = dyn.d_tag;
 
             switch (tag) {
             case DT_HASH:
@@ -218,7 +249,7 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap)
             case DT_PLTGOT:
             case DT_ADDRRNGLO ... DT_ADDRRNGHI:
                 /* These entries store an address in the entry. */
-                output_reloc(outf, buf, &dyn->d_un.d_val);
+                output_reloc(outf, buf, &target_dyn->d_un.d_val);
                 break;
 
             case DT_NULL:
@@ -235,7 +266,7 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap)
                 break;
 
             case DT_SYMENT:
-                if (dyn->d_un.d_val != sizeof(ElfN(Sym))) {
+                if (dyn.d_un.d_val != sizeof(ElfN(Sym))) {
                     fprintf(stderr, "VDSO has incorrect dynamic symbol size\n");
                     errors++;
                 }
@@ -251,7 +282,7 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap)
                  * ??? The RISC-V toolchain will emit these even when there
                  * are no relocations.  Validate zeros.
                  */
-                if (dyn->d_un.d_val != 0) {
+                if (dyn.d_un.d_val != 0) {
                     fprintf(stderr, "VDSO has dynamic relocations\n");
                     errors++;
                 }
@@ -287,7 +318,7 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap)
                 errors++;
                 break;
             }
-            dyn++;
+            target_dyn++;
         } while (tag != DT_NULL);
         if (errors) {
             exit(EXIT_FAILURE);
@@ -296,11 +327,11 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap)
 
     /* Relocate the dynamic symbol table. */
     if (dynsym_idx) {
-        ElfN(Sym) *sym = buf + shdr[dynsym_idx].sh_offset;
-        unsigned sym_n = shdr[dynsym_idx].sh_size / sizeof(*sym);
+        ElfN(Sym) *target_sym = buf + shdr[dynsym_idx].sh_offset;
+        unsigned sym_n = shdr[dynsym_idx].sh_size / sizeof(*target_sym);
 
         for (unsigned i = 0; i < sym_n; ++i) {
-            output_reloc(outf, buf, &sym[i].st_value);
+            output_reloc(outf, buf, &target_sym[i].st_value);
         }
     }
 
@@ -311,4 +342,9 @@ static void elfN(process)(FILE *outf, void *buf, bool need_bswap)
     if (symtab_idx) {
         elfN(search_symtab)(shdr, symtab_idx, buf, need_bswap);
     }
+
+    if (need_bswap) {
+        elfN(bswap_ps_hdrs)(buf);
+        elfN(bswap_ehdr)(buf);
+    }
 }
diff --git a/linux-user/gen-vdso.c b/linux-user/gen-vdso.c
index 31e333be80..721f38d5a3 100644
--- a/linux-user/gen-vdso.c
+++ b/linux-user/gen-vdso.c
@@ -132,23 +132,6 @@ int main(int argc, char **argv)
     fclose(inf);
 
     /*
-     * Write out the vdso image now, before we make local changes.
-     */
-
-    fprintf(outf,
-            "/* Automatically generated from linux-user/gen-vdso.c. */\n"
-            "\n"
-            "static const uint8_t %s_image[] = {",
-            prefix);
-    for (long i = 0; i < total_len; ++i) {
-        if (i % 12 == 0) {
-            fputs("\n   ", outf);
-        }
-        fprintf(outf, " 0x%02x,", buf[i]);
-    }
-    fprintf(outf, "\n};\n\n");
-
-    /*
      * Identify which elf flavor we're processing.
      * The first 16 bytes of the file are e_ident.
      */
@@ -179,14 +162,17 @@ int main(int argc, char **argv)
      * Output relocation addresses as we go.
      */
 
-    fprintf(outf, "static const unsigned %s_relocs[] = {\n", prefix);
+    fprintf(outf,
+            "/* Automatically generated by linux-user/gen-vdso.c. */\n"
+            "\n"
+            "static const unsigned %s_relocs[] = {\n", prefix);
 
     switch (buf[EI_CLASS]) {
     case ELFCLASS32:
-        elf32_process(outf, buf, need_bswap);
+        elf32_process(outf, buf, total_len, need_bswap);
         break;
     case ELFCLASS64:
-        elf64_process(outf, buf, need_bswap);
+        elf64_process(outf, buf, total_len, need_bswap);
         break;
     default:
         fprintf(stderr, "%s: invalid elf EI_CLASS (%u)\n",
@@ -196,6 +182,20 @@ int main(int argc, char **argv)
 
     fprintf(outf, "};\n\n");   /* end vdso_relocs. */
 
+    /*
+     * Write out the vdso image now, after we made local changes.
+     */
+    fprintf(outf,
+            "static const uint8_t %s_image[] = {",
+            prefix);
+    for (long i = 0; i < total_len; ++i) {
+        if (i % 12 == 0) {
+            fputs("\n   ", outf);
+        }
+        fprintf(outf, " 0x%02x,", buf[i]);
+    }
+    fprintf(outf, "\n};\n\n");
+
     fprintf(outf, "static const VdsoImageInfo %s_image_info = {\n", prefix);
     fprintf(outf, "    .image = %s_image,\n", prefix);
     fprintf(outf, "    .relocs = %s_relocs,\n", prefix);
diff --git a/linux-user/main.c b/linux-user/main.c
index 8143a0d4b0..b09af8d436 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -412,6 +412,13 @@ static void handle_arg_reserved_va(const char *arg)
     reserved_va = val ? val - 1 : 0;
 }
 
+static const char *rtsig_map = CONFIG_QEMU_RTSIG_MAP;
+
+static void handle_arg_rtsig_map(const char *arg)
+{
+    rtsig_map = arg;
+}
+
 static void handle_arg_one_insn_per_tb(const char *arg)
 {
     opt_one_insn_per_tb = true;
@@ -494,6 +501,9 @@ static const struct qemu_argument arg_table[] = {
      "address",    "set guest_base address to 'address'"},
     {"R",          "QEMU_RESERVED_VA", true,  handle_arg_reserved_va,
      "size",       "reserve 'size' bytes for guest virtual address space"},
+    {"t",          "QEMU_RTSIG_MAP",   true,  handle_arg_rtsig_map,
+     "tsig hsig n[,...]",
+                   "map target rt signals [tsig,tsig+n) to [hsig,hsig+n]"},
     {"d",          "QEMU_LOG",         true,  handle_arg_log,
      "item[,...]", "enable logging of specified items "
      "(use '-d help' for a list of items)"},
@@ -1002,7 +1012,7 @@ int main(int argc, char **argv, char **envp)
 
     target_set_brk(info->brk);
     syscall_init();
-    signal_init();
+    signal_init(rtsig_map);
 
     /* Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
        generating the prologue until now so that the prologue can take
diff --git a/linux-user/signal-common.h b/linux-user/signal-common.h
index f4cbe6185e..8584d9ecc2 100644
--- a/linux-user/signal-common.h
+++ b/linux-user/signal-common.h
@@ -56,7 +56,7 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
                     target_sigset_t *set, CPUArchState *env);
 
 void process_pending_signals(CPUArchState *cpu_env);
-void signal_init(void);
+void signal_init(const char *rtsig_map);
 void queue_signal(CPUArchState *env, int sig, int si_type,
                   target_siginfo_t *info);
 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info);
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 63ac2df53b..9b6d772882 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -18,6 +18,7 @@
  */
 #include "qemu/osdep.h"
 #include "qemu/bitops.h"
+#include "qemu/cutils.h"
 #include "gdbstub/user.h"
 #include "exec/page-protection.h"
 #include "hw/core/tcg-cpu-ops.h"
@@ -513,20 +514,81 @@ static int core_dump_signal(int sig)
     }
 }
 
-static void signal_table_init(void)
+static void signal_table_init(const char *rtsig_map)
 {
     int hsig, tsig, count;
 
+    if (rtsig_map) {
+        /*
+         * Map host RT signals to target RT signals according to the
+         * user-provided specification.
+         */
+        const char *s = rtsig_map;
+
+        while (true) {
+            int i;
+
+            if (qemu_strtoi(s, &s, 10, &tsig) || *s++ != ' ') {
+                fprintf(stderr, "Malformed target signal in QEMU_RTSIG_MAP\n");
+                exit(EXIT_FAILURE);
+            }
+            if (qemu_strtoi(s, &s, 10, &hsig) || *s++ != ' ') {
+                fprintf(stderr, "Malformed host signal in QEMU_RTSIG_MAP\n");
+                exit(EXIT_FAILURE);
+            }
+            if (qemu_strtoi(s, &s, 10, &count) || (*s && *s != ',')) {
+                fprintf(stderr, "Malformed signal count in QEMU_RTSIG_MAP\n");
+                exit(EXIT_FAILURE);
+            }
+
+            for (i = 0; i < count; i++, tsig++, hsig++) {
+                if (tsig < TARGET_SIGRTMIN || tsig > TARGET_NSIG) {
+                    fprintf(stderr, "%d is not a target rt signal\n", tsig);
+                    exit(EXIT_FAILURE);
+                }
+                if (hsig < SIGRTMIN || hsig > SIGRTMAX) {
+                    fprintf(stderr, "%d is not a host rt signal\n", hsig);
+                    exit(EXIT_FAILURE);
+                }
+                if (host_to_target_signal_table[hsig]) {
+                    fprintf(stderr, "%d already maps %d\n",
+                            hsig, host_to_target_signal_table[hsig]);
+                    exit(EXIT_FAILURE);
+                }
+                host_to_target_signal_table[hsig] = tsig;
+            }
+
+            if (*s) {
+                s++;
+            } else {
+                break;
+            }
+        }
+    } else {
+        /*
+         * Default host-to-target RT signal mapping.
+         *
+         * Signals are supported starting from TARGET_SIGRTMIN and going up
+         * until we run out of host realtime signals.  Glibc uses the lower 2
+         * RT signals and (hopefully) nobody uses the upper ones.
+         * This is why SIGRTMIN (34) is generally greater than __SIGRTMIN (32).
+         * To fix this properly we would need to do manual signal delivery
+         * multiplexed over a single host signal.
+         * Attempts for configure "missing" signals via sigaction will be
+         * silently ignored.
+         *
+         * Reserve one signal for internal usage (see below).
+         */
+
+        hsig = SIGRTMIN + 1;
+        for (tsig = TARGET_SIGRTMIN;
+             hsig <= SIGRTMAX && tsig <= TARGET_NSIG;
+             hsig++, tsig++) {
+            host_to_target_signal_table[hsig] = tsig;
+        }
+    }
+
     /*
-     * Signals are supported starting from TARGET_SIGRTMIN and going up
-     * until we run out of host realtime signals.  Glibc uses the lower 2
-     * RT signals and (hopefully) nobody uses the upper ones.
-     * This is why SIGRTMIN (34) is generally greater than __SIGRTMIN (32).
-     * To fix this properly we would need to do manual signal delivery
-     * multiplexed over a single host signal.
-     * Attempts for configure "missing" signals via sigaction will be
-     * silently ignored.
-     *
      * Remap the target SIGABRT, so that we can distinguish host abort
      * from guest abort.  When the guest registers a signal handler or
      * calls raise(SIGABRT), the host will raise SIG_RTn.  If the guest
@@ -536,21 +598,27 @@ static void signal_table_init(void)
      * parent sees the correct mapping from wait status.
      */
 
-    hsig = SIGRTMIN;
     host_to_target_signal_table[SIGABRT] = 0;
-    host_to_target_signal_table[hsig++] = TARGET_SIGABRT;
-
-    for (tsig = TARGET_SIGRTMIN;
-         hsig <= SIGRTMAX && tsig <= TARGET_NSIG;
-         hsig++, tsig++) {
-        host_to_target_signal_table[hsig] = tsig;
+    for (hsig = SIGRTMIN; hsig <= SIGRTMAX; hsig++) {
+        if (!host_to_target_signal_table[hsig]) {
+            host_to_target_signal_table[hsig] = TARGET_SIGABRT;
+            break;
+        }
+    }
+    if (hsig > SIGRTMAX) {
+        fprintf(stderr, "No rt signals left for SIGABRT mapping\n");
+        exit(EXIT_FAILURE);
     }
 
     /* Invert the mapping that has already been assigned. */
     for (hsig = 1; hsig < _NSIG; hsig++) {
         tsig = host_to_target_signal_table[hsig];
         if (tsig) {
-            assert(target_to_host_signal_table[tsig] == 0);
+            if (target_to_host_signal_table[tsig]) {
+                fprintf(stderr, "%d is already mapped to %d\n",
+                        tsig, target_to_host_signal_table[tsig]);
+                exit(EXIT_FAILURE);
+            }
             target_to_host_signal_table[tsig] = hsig;
         }
     }
@@ -573,13 +641,13 @@ static void signal_table_init(void)
     trace_signal_table_init(count);
 }
 
-void signal_init(void)
+void signal_init(const char *rtsig_map)
 {
     TaskState *ts = get_task_state(thread_cpu);
     struct sigaction act, oact;
 
     /* initialize signal conversion tables */
-    signal_table_init();
+    signal_table_init(rtsig_map);
 
     /* Set the signal mask from the host mask. */
     sigprocmask(0, 0, &ts->signal_mask);