Merge tag 'pull-tcg-20241008' of https://gitlab.com/rth7680/qemu into staging

linux-user: Fix parse_elf_properties GNU0_MAGIC check
linux-user: Various improvements to strace
linux-user: Add openat2 support
linux-user/flatload: Take mmap_lock in load_flt_binary()
accel/tcg: Make page_set_flags() documentation public
tcg/ppc: Use TCG_REG_TMP2 for scratch tcg_out_qemu_st
tcg/ppc: Use TCG_REG_TMP2 for scratch index in prepare_host_addr
target/m68k: Always return a temporary from gen_lea_mode

# -----BEGIN PGP SIGNATURE-----
#
# iQFRBAABCgA7FiEEekgeeIaLTbaoWgXAZN846K9+IV8FAmcFeLQdHHJpY2hhcmQu
# aGVuZGVyc29uQGxpbmFyby5vcmcACgkQZN846K9+IV+8Wgf9FJb/71zPAg7idUo8
# k+P5hOmE0PzPKdkoCh5WP0+TF4m/gMc3ABMFO2ABx4EcAkWxUmNP1Po5Lb0/A9Gq
# LuSDRJVk3jSeGebmMsIH0SVzKY3ewQv7ZGB6A2uFdXtkwDUCxgHUQcfQY9yvjFut
# eU11zWkPbmbI4bwz9Y+Tyv9LOXRk/Br5B/uQEzQ9/Go/0OeJP0iTXre/veGufqND
# wK35AoDCVNomjw6h2Fg0t3kCt/mtR8W8D16+4QhsH+iE9IQMmhj4itz8Uq2ikh29
# lQIUT8acHC8fNUQJXw0nPXbNsimp/GyRGJiYCH7g7V67o/fjDUSbYMxk2TMZPuJV
# dGy3KQ==
# =UeX8
# -----END PGP SIGNATURE-----
# gpg: Signature made Tue 08 Oct 2024 19:23:48 BST
# 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-tcg-20241008' of https://gitlab.com/rth7680/qemu:
  accel/tcg: Make page_set_flags() documentation public
  target/m68k: Always return a temporary from gen_lea_mode
  tcg/ppc: Use TCG_REG_TMP2 for scratch index in prepare_host_addr
  tcg/ppc: Use TCG_REG_TMP2 for scratch tcg_out_qemu_st
  linux-user: Add strace for recvfrom()
  linux-user: Add strace for sendto()
  linux-user: Factor print_buf_len() out
  linux-user: Display sockaddr buffer as pointer
  linux-user: Correct print_sockaddr() format
  linux-user: Trace wait4()'s and waitpid()'s wstatus
  linux-user: add strace support for openat2
  linux-user: add openat2 support in linux-user
  linux-user: Fix parse_elf_properties GNU0_MAGIC check
  linux-user/flatload: Take mmap_lock in load_flt_binary()

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

12 files changed, 321 insertions, 36 deletions

diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
index 7ddc47b..11b6d45 100644
--- a/accel/tcg/user-exec.c
+++ b/accel/tcg/user-exec.c
@@ -485,11 +485,6 @@ static bool pageflags_set_clear(target_ulong start, target_ulong last,
     return inval_tb;
 }
 
-/*
- * Modify the flags of a page and invalidate the code if necessary.
- * The flag PAGE_WRITE_ORG is positioned automatically depending
- * on PAGE_WRITE.  The mmap_lock should already be held.
- */
 void page_set_flags(target_ulong start, target_ulong last, int flags)
 {
     bool reset = false;
diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index 6f09b86..45e6676 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -166,7 +166,20 @@ typedef int (*walk_memory_regions_fn)(void *, target_ulong,
 int walk_memory_regions(void *, walk_memory_regions_fn);
 
 int page_get_flags(target_ulong address);
+
+/**
+ * page_set_flags:
+ * @start: first byte of range
+ * @last: last byte of range
+ * @flags: flags to set
+ * Context: holding mmap lock
+ *
+ * Modify the flags of a page and invalidate the code if necessary.
+ * The flag PAGE_WRITE_ORG is positioned automatically depending
+ * on PAGE_WRITE.  The mmap_lock should already be held.
+ */
 void page_set_flags(target_ulong start, target_ulong last, int flags);
+
 void page_reset_target_data(target_ulong start, target_ulong last);
 
 /**
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 0678c9d..52c88a6 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -3121,11 +3121,11 @@ static bool parse_elf_properties(const ImageSource *src,
     }
 
     /*
-     * The contents of a valid PT_GNU_PROPERTY is a sequence
-     * of uint32_t -- swap them all now.
+     * The contents of a valid PT_GNU_PROPERTY is a sequence of uint32_t.
+     * Swap most of them now, beyond the header and namesz.
      */
 #ifdef BSWAP_NEEDED
-    for (int i = 0; i < n / 4; i++) {
+    for (int i = 4; i < n / 4; i++) {
         bswap32s(note.data + i);
     }
 #endif
@@ -3135,15 +3135,15 @@ static bool parse_elf_properties(const ImageSource *src,
      * immediately follows nhdr and is thus at the 4th word.  Further, all
      * of the inputs to the kernel's round_up are multiples of 4.
      */
-    if (note.nhdr.n_type != NT_GNU_PROPERTY_TYPE_0 ||
-        note.nhdr.n_namesz != NOTE_NAME_SZ ||
+    if (tswap32(note.nhdr.n_type) != NT_GNU_PROPERTY_TYPE_0 ||
+        tswap32(note.nhdr.n_namesz) != NOTE_NAME_SZ ||
         note.data[3] != GNU0_MAGIC) {
         error_setg(errp, "Invalid note in PT_GNU_PROPERTY");
         return false;
     }
     off = sizeof(note.nhdr) + NOTE_NAME_SZ;
 
-    datasz = note.nhdr.n_descsz + off;
+    datasz = tswap32(note.nhdr.n_descsz) + off;
     if (datasz > n) {
         error_setg(errp, "Invalid note size in PT_GNU_PROPERTY");
         return false;
diff --git a/linux-user/flatload.c b/linux-user/flatload.c
index 04d8138..0e4be5b 100644
--- a/linux-user/flatload.c
+++ b/linux-user/flatload.c
@@ -487,7 +487,10 @@ int load_flt_binary(struct linux_binprm *bprm, struct image_info *info)
     stack_len += (bprm->envc + 1) * 4; /* the envp array */
 
 
+    mmap_lock();
     res = load_flat_file(bprm, libinfo, 0, &stack_len);
+    mmap_unlock();
+
     if (is_error(res)) {
             return res;
     }
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 2e90a97..98ad848 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -313,6 +313,15 @@ static inline bool access_ok(CPUState *cpu, int type,
 int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len);
 int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len);
 
+/*
+ * copy_struct_from_user() copies a target struct to a host struct, in
+ * a way that guarantees backwards-compatibility for struct syscall
+ * arguments.
+ *
+ * Similar to kernels uaccess.h:copy_struct_from_user()
+ */
+int copy_struct_from_user(void *dst, size_t ksize, abi_ptr src, size_t usize);
+
 /* Functions for accessing guest memory.  The tget and tput functions
    read/write single values, byteswapping as necessary.  The lock_user function
    gets a pointer to a contiguous area of guest memory, but does not perform
diff --git a/linux-user/strace.c b/linux-user/strace.c
index b4d1098..c3eb3a2 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -13,6 +13,9 @@
 #include <linux/if_packet.h>
 #include <linux/in6.h>
 #include <linux/netlink.h>
+#ifdef HAVE_OPENAT2_H
+#include <linux/openat2.h>
+#endif
 #include <sched.h>
 #include "qemu.h"
 #include "user-internals.h"
@@ -373,7 +376,7 @@ print_sockaddr(abi_ulong addr, abi_long addrlen, int last)
                  un->sun_path[i]; i++) {
                 qemu_log("%c", un->sun_path[i]);
             }
-            qemu_log("\"}");
+            qemu_log("\"},");
             break;
         }
         case AF_INET: {
@@ -383,7 +386,7 @@ print_sockaddr(abi_ulong addr, abi_long addrlen, int last)
                      ntohs(in->sin_port));
             qemu_log("sin_addr=inet_addr(\"%d.%d.%d.%d\")",
                      c[0], c[1], c[2], c[3]);
-            qemu_log("}");
+            qemu_log("},");
             break;
         }
         case AF_PACKET: {
@@ -414,12 +417,12 @@ print_sockaddr(abi_ulong addr, abi_long addrlen, int last)
             }
             qemu_log(",sll_addr=%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
                      c[0], c[1], c[2], c[3], c[4], c[5], c[6], c[7]);
-            qemu_log("}");
+            qemu_log("},");
             break;
         }
         case AF_NETLINK: {
             struct target_sockaddr_nl *nl = (struct target_sockaddr_nl *)sa;
-            qemu_log("{nl_family=AF_NETLINK,nl_pid=%u,nl_groups=%u}",
+            qemu_log("{nl_family=AF_NETLINK,nl_pid=%u,nl_groups=%u},",
                      tswap32(nl->nl_pid), tswap32(nl->nl_groups));
             break;
         }
@@ -429,14 +432,14 @@ print_sockaddr(abi_ulong addr, abi_long addrlen, int last)
                 qemu_log("%02x, ", sa->sa_data[i]);
             }
             qemu_log("%02x}", sa->sa_data[i]);
-            qemu_log("}");
+            qemu_log("},");
             break;
         }
         unlock_user(sa, addr, 0);
     } else {
-        print_raw_param("0x"TARGET_ABI_FMT_lx, addr, 0);
+        print_pointer(addr, 0);
     }
-    qemu_log(", "TARGET_ABI_FMT_ld"%s", addrlen, get_comma(last));
+    qemu_log(TARGET_ABI_FMT_ld"%s", addrlen, get_comma(last));
 }
 
 static void
@@ -1063,6 +1066,18 @@ UNUSED static const struct flags open_flags[] = {
     FLAG_END,
 };
 
+UNUSED static const struct flags openat2_resolve_flags[] = {
+#ifdef HAVE_OPENAT2_H
+    FLAG_GENERIC(RESOLVE_NO_XDEV),
+    FLAG_GENERIC(RESOLVE_NO_MAGICLINKS),
+    FLAG_GENERIC(RESOLVE_NO_SYMLINKS),
+    FLAG_GENERIC(RESOLVE_BENEATH),
+    FLAG_GENERIC(RESOLVE_IN_ROOT),
+    FLAG_GENERIC(RESOLVE_CACHED),
+#endif
+    FLAG_END,
+};
+
 UNUSED static const struct flags mount_flags[] = {
 #ifdef MS_BIND
     FLAG_GENERIC(MS_BIND),
@@ -1655,6 +1670,13 @@ print_buf(abi_long addr, abi_long len, int last)
     }
 }
 
+static void
+print_buf_len(abi_long addr, abi_long len, int last)
+{
+    print_buf(addr, len, 0);
+    print_raw_param(TARGET_ABI_FMT_ld, len, last);
+}
+
 /*
  * Prints out raw parameter using given format.  Caller needs
  * to do byte swapping if needed.
@@ -2742,8 +2764,7 @@ static void do_print_sendrecv(const char *name, abi_long arg1)
 
     qemu_log("%s(", name);
     print_sockfd(sockfd, 0);
-    print_buf(msg, len, 0);
-    print_raw_param(TARGET_ABI_FMT_ld, len, 0);
+    print_buf_len(msg, len, 0);
     print_flags(msg_flags, flags, 1);
     qemu_log(")");
 }
@@ -2761,8 +2782,7 @@ static void do_print_msgaddr(const char *name, abi_long arg1)
 
     qemu_log("%s(", name);
     print_sockfd(sockfd, 0);
-    print_buf(msg, len, 0);
-    print_raw_param(TARGET_ABI_FMT_ld, len, 0);
+    print_buf_len(msg, len, 0);
     print_flags(msg_flags, flags, 0);
     print_sockaddr(addr, addrlen, 0);
     qemu_log(")");
@@ -3122,6 +3142,38 @@ print_bind(CPUArchState *cpu_env, const struct syscallname *name,
 }
 #endif
 
+#ifdef TARGET_NR_recvfrom
+static void
+print_recvfrom(CPUArchState *cpu_env, const struct syscallname *name,
+               abi_long arg0, abi_long arg1, abi_long arg2,
+               abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_prologue(name);
+    print_sockfd(arg0, 0);
+    print_pointer(arg1, 0); /* output */
+    print_raw_param(TARGET_ABI_FMT_ld, arg2, 0);
+    print_flags(msg_flags, arg3, 0);
+    print_pointer(arg4, 0); /* output */
+    print_pointer(arg5, 1); /* in/out */
+    print_syscall_epilogue(name);
+}
+#endif
+
+#ifdef TARGET_NR_sendto
+static void
+print_sendto(CPUArchState *cpu_env, const struct syscallname *name,
+             abi_long arg0, abi_long arg1, abi_long arg2,
+             abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_prologue(name);
+    print_sockfd(arg0, 0);
+    print_buf_len(arg1, arg2, 0);
+    print_flags(msg_flags, arg3, 0);
+    print_sockaddr(arg4, arg5, 1);
+    print_syscall_epilogue(name);
+}
+#endif
+
 #if defined(TARGET_NR_stat) || defined(TARGET_NR_stat64) || \
     defined(TARGET_NR_lstat) || defined(TARGET_NR_lstat64)
 static void
@@ -3483,6 +3535,38 @@ print_openat(CPUArchState *cpu_env, const struct syscallname *name,
 }
 #endif
 
+#ifdef TARGET_NR_openat2
+static void
+print_openat2(CPUArchState *cpu_env, const struct syscallname *name,
+              abi_long arg0, abi_long arg1, abi_long arg2,
+              abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    struct open_how_ver0 how;
+
+    print_syscall_prologue(name);
+    print_at_dirfd(arg0, 0);
+    print_string(arg1, 0);
+
+    if ((abi_ulong)arg3 >= sizeof(struct target_open_how_ver0) &&
+        copy_struct_from_user(&how, sizeof(how), arg2, arg3) == 0) {
+        how.flags = tswap64(how.flags);
+        how.mode = tswap64(how.mode);
+        how.resolve = tswap64(how.resolve);
+        qemu_log("{");
+        print_open_flags(how.flags, 0);
+        if (how.flags & TARGET_O_CREAT) {
+            print_file_mode(how.mode, 0);
+        }
+        print_flags(openat2_resolve_flags, how.resolve, 1);
+        qemu_log("},");
+    } else {
+        print_pointer(arg2, 0);
+    }
+    print_raw_param(TARGET_ABI_FMT_lu, arg3, 1);
+    print_syscall_epilogue(name);
+}
+#endif
+
 #ifdef TARGET_NR_pidfd_send_signal
 static void
 print_pidfd_send_signal(CPUArchState *cpu_env, const struct syscallname *name,
@@ -4168,6 +4252,63 @@ print_ioctl(CPUArchState *cpu_env, const struct syscallname *name,
 }
 #endif
 
+#if defined(TARGET_NR_wait4) || defined(TARGET_NR_waitpid)
+static void print_wstatus(int wstatus)
+{
+    if (WIFSIGNALED(wstatus)) {
+        qemu_log("{WIFSIGNALED(s) && WTERMSIG(s) == ");
+        print_signal(WTERMSIG(wstatus), 1);
+        if (WCOREDUMP(wstatus)) {
+            qemu_log(" && WCOREDUMP(s)");
+        }
+        qemu_log("}");
+    } else if (WIFEXITED(wstatus)) {
+        qemu_log("{WIFEXITED(s) && WEXITSTATUS(s) == %d}",
+                 WEXITSTATUS(wstatus));
+    } else {
+        print_number(wstatus, 1);
+    }
+}
+
+static void print_ret_wstatus(abi_long ret, abi_long wstatus_addr)
+{
+    int wstatus;
+
+    if (!print_syscall_err(ret)
+        && wstatus_addr
+        && get_user_s32(wstatus, wstatus_addr)) {
+        qemu_log(TARGET_ABI_FMT_ld " (wstatus=", ret);
+        print_wstatus(wstatus);
+        qemu_log(")");
+    }
+    qemu_log("\n");
+}
+#endif
+
+#ifdef TARGET_NR_wait4
+static void
+print_syscall_ret_wait4(CPUArchState *cpu_env,
+                        const struct syscallname *name,
+                        abi_long ret, abi_long arg0, abi_long arg1,
+                        abi_long arg2, abi_long arg3, abi_long arg4,
+                        abi_long arg5)
+{
+    print_ret_wstatus(ret, arg1);
+}
+#endif
+
+#ifdef TARGET_NR_waitpid
+static void
+print_syscall_ret_waitpid(CPUArchState *cpu_env,
+                          const struct syscallname *name,
+                          abi_long ret, abi_long arg0, abi_long arg1,
+                          abi_long arg2, abi_long arg3, abi_long arg4,
+                          abi_long arg5)
+{
+    print_ret_wstatus(ret, arg1);
+}
+#endif
+
 /*
  * An array of all of the syscalls we know about
  */
diff --git a/linux-user/strace.list b/linux-user/strace.list
index dfd4237..0d69fb3 100644
--- a/linux-user/strace.list
+++ b/linux-user/strace.list
@@ -715,6 +715,9 @@
 #ifdef TARGET_NR_openat
 { TARGET_NR_openat, "openat" , NULL, print_openat, NULL },
 #endif
+#ifdef TARGET_NR_openat2
+{ TARGET_NR_openat2, "openat2" , NULL, print_openat2, NULL },
+#endif
 #ifdef TARGET_NR_osf_adjtime
 { TARGET_NR_osf_adjtime, "osf_adjtime" , NULL, NULL, NULL },
 #endif
@@ -1135,7 +1138,7 @@
 { TARGET_NR_recv, "recv" , "%s(%d,%p,%u,%d)", NULL, NULL },
 #endif
 #ifdef TARGET_NR_recvfrom
-{ TARGET_NR_recvfrom, "recvfrom" , NULL, NULL, NULL },
+{ TARGET_NR_recvfrom, "recvfrom" , NULL, print_recvfrom, NULL },
 #endif
 #ifdef TARGET_NR_recvmmsg
 { TARGET_NR_recvmmsg, "recvmmsg" , NULL, NULL, NULL },
@@ -1285,7 +1288,7 @@
 { TARGET_NR_sendmsg, "sendmsg" , NULL, NULL, NULL },
 #endif
 #ifdef TARGET_NR_sendto
-{ TARGET_NR_sendto, "sendto" , NULL, NULL, NULL },
+{ TARGET_NR_sendto, "sendto" , NULL, print_sendto, NULL },
 #endif
 #ifdef TARGET_NR_setdomainname
 { TARGET_NR_setdomainname, "setdomainname" , NULL, NULL, NULL },
@@ -1659,13 +1662,15 @@
 { TARGET_NR_vserver, "vserver" , NULL, NULL, NULL },
 #endif
 #ifdef TARGET_NR_wait4
-{ TARGET_NR_wait4, "wait4" , "%s(%d,%p,%d,%p)", NULL, NULL },
+{ TARGET_NR_wait4, "wait4" , "%s(%d,%p,%d,%p)", NULL,
+                   print_syscall_ret_wait4 },
 #endif
 #ifdef TARGET_NR_waitid
 { TARGET_NR_waitid, "waitid" , "%s(%#x,%d,%p,%#x)", NULL, NULL },
 #endif
 #ifdef TARGET_NR_waitpid
-{ TARGET_NR_waitpid, "waitpid" , "%s(%d,%p,%#x)", NULL, NULL },
+{ TARGET_NR_waitpid, "waitpid", "%s(%d,%p,%#x)", NULL,
+                     print_syscall_ret_waitpid },
 #endif
 #ifdef TARGET_NR_write
 { TARGET_NR_write, "write" , "%s(%d,%#x,%d)", NULL, NULL },
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index a666986..1354e75 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -602,6 +602,33 @@ static int check_zeroed_user(abi_long addr, size_t ksize, size_t usize)
     return 1;
 }
 
+/*
+ * Copies a target struct to a host struct, in a way that guarantees
+ * backwards-compatibility for struct syscall arguments.
+ *
+ * Similar to kernels uaccess.h:copy_struct_from_user()
+ */
+int copy_struct_from_user(void *dst, size_t ksize, abi_ptr src, size_t usize)
+{
+    size_t size = MIN(ksize, usize);
+    size_t rest = MAX(ksize, usize) - size;
+
+    /* Deal with trailing bytes. */
+    if (usize < ksize) {
+        memset(dst + size, 0, rest);
+    } else if (usize > ksize) {
+        int ret = check_zeroed_user(src, ksize, usize);
+        if (ret <= 0) {
+            return ret ?: -TARGET_E2BIG;
+        }
+    }
+    /* Copy the interoperable parts of the struct. */
+    if (copy_from_user(dst, src, size)) {
+        return -TARGET_EFAULT;
+    }
+    return 0;
+}
+
 #define safe_syscall0(type, name) \
 static type safe_##name(void) \
 { \
@@ -653,6 +680,10 @@ safe_syscall3(ssize_t, read, int, fd, void *, buff, size_t, count)
 safe_syscall3(ssize_t, write, int, fd, const void *, buff, size_t, count)
 safe_syscall4(int, openat, int, dirfd, const char *, pathname, \
               int, flags, mode_t, mode)
+
+safe_syscall4(int, openat2, int, dirfd, const char *, pathname, \
+              const struct open_how_ver0 *, how, size_t, size)
+
 #if defined(TARGET_NR_wait4) || defined(TARGET_NR_waitpid)
 safe_syscall4(pid_t, wait4, pid_t, pid, int *, status, int, options, \
               struct rusage *, rusage)
@@ -8332,8 +8363,9 @@ static int open_net_route(CPUArchState *cpu_env, int fd)
 }
 #endif
 
-int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *fname,
-                    int flags, mode_t mode, bool safe)
+static int maybe_do_fake_open(CPUArchState *cpu_env, int dirfd,
+                              const char *fname, int flags, mode_t mode,
+                              int openat2_resolve, bool safe)
 {
     g_autofree char *proc_name = NULL;
     const char *pathname;
@@ -8370,6 +8402,12 @@ int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *fname,
     }
 
     if (is_proc_myself(pathname, "exe")) {
+        /* Honor openat2 resolve flags */
+        if ((openat2_resolve & RESOLVE_NO_MAGICLINKS) ||
+            (openat2_resolve & RESOLVE_NO_SYMLINKS)) {
+            errno = ELOOP;
+            return -1;
+        }
         if (safe) {
             return safe_openat(dirfd, exec_path, flags, mode);
         } else {
@@ -8416,6 +8454,17 @@ int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *fname,
         return fd;
     }
 
+    return -2;
+}
+
+int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
+                    int flags, mode_t mode, bool safe)
+{
+    int fd = maybe_do_fake_open(cpu_env, dirfd, pathname, flags, mode, 0, safe);
+    if (fd > -2) {
+        return fd;
+    }
+
     if (safe) {
         return safe_openat(dirfd, path(pathname), flags, mode);
     } else {
@@ -8423,6 +8472,49 @@ int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *fname,
     }
 }
 
+
+static int do_openat2(CPUArchState *cpu_env, abi_long dirfd,
+                      abi_ptr guest_pathname, abi_ptr guest_open_how,
+                      abi_ulong guest_size)
+{
+    struct open_how_ver0 how = {0};
+    char *pathname;
+    int ret;
+
+    if (guest_size < sizeof(struct target_open_how_ver0)) {
+        return -TARGET_EINVAL;
+    }
+    ret = copy_struct_from_user(&how, sizeof(how), guest_open_how, guest_size);
+    if (ret) {
+        if (ret == -TARGET_E2BIG) {
+            qemu_log_mask(LOG_UNIMP,
+                          "Unimplemented openat2 open_how size: "
+                          TARGET_ABI_FMT_lu "\n", guest_size);
+        }
+        return ret;
+    }
+    pathname = lock_user_string(guest_pathname);
+    if (!pathname) {
+        return -TARGET_EFAULT;
+    }
+
+    how.flags = target_to_host_bitmask(tswap64(how.flags), fcntl_flags_tbl);
+    how.mode = tswap64(how.mode);
+    how.resolve = tswap64(how.resolve);
+    int fd = maybe_do_fake_open(cpu_env, dirfd, pathname, how.flags, how.mode,
+                                how.resolve, true);
+    if (fd > -2) {
+        ret = get_errno(fd);
+    } else {
+        ret = get_errno(safe_openat2(dirfd, pathname, &how,
+                                     sizeof(struct open_how_ver0)));
+    }
+
+    fd_trans_unregister(ret);
+    unlock_user(pathname, guest_pathname, 0);
+    return ret;
+}
+
 ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz)
 {
     ssize_t ret;
@@ -9195,6 +9287,9 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
         fd_trans_unregister(ret);
         unlock_user(p, arg2, 0);
         return ret;
+    case TARGET_NR_openat2:
+        ret = do_openat2(cpu_env, arg1, arg2, arg3, arg4);
+        return ret;
 #if defined(TARGET_NR_name_to_handle_at) && defined(CONFIG_OPEN_BY_HANDLE)
     case TARGET_NR_name_to_handle_at:
         ret = do_name_to_handle_at(arg1, arg2, arg3, arg4, arg5);
diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index e08d088..0ade837 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -2748,4 +2748,22 @@ struct target_sched_param {
     abi_int sched_priority;
 };
 
+/* from kernel's include/uapi/linux/openat2.h */
+struct open_how_ver0 {
+    __u64 flags;
+    __u64 mode;
+    __u64 resolve;
+};
+struct target_open_how_ver0 {
+    abi_ullong flags;
+    abi_ullong mode;
+    abi_ullong resolve;
+};
+#ifndef RESOLVE_NO_MAGICLINKS
+#define RESOLVE_NO_MAGICLINKS   0x02
+#endif
+#ifndef RESOLVE_NO_SYMLINKS
+#define RESOLVE_NO_SYMLINKS     0x04
+#endif
+
 #endif
diff --git a/meson.build b/meson.build
index 33954b3..4ea1984 100644
--- a/meson.build
+++ b/meson.build
@@ -2481,6 +2481,7 @@ config_host_data.set('CONFIG_LINUX_MAGIC_H', cc.has_header('linux/magic.h'))
 config_host_data.set('CONFIG_VALGRIND_H', cc.has_header('valgrind/valgrind.h'))
 config_host_data.set('HAVE_BTRFS_H', cc.has_header('linux/btrfs.h'))
 config_host_data.set('HAVE_DRM_H', cc.has_header('libdrm/drm.h'))
+config_host_data.set('HAVE_OPENAT2_H', cc.has_header('linux/openat2.h'))
 config_host_data.set('HAVE_PTY_H', cc.has_header('pty.h'))
 config_host_data.set('HAVE_SYS_DISK_H', cc.has_header('sys/disk.h'))
 config_host_data.set('HAVE_SYS_IOCCOM_H', cc.has_header('sys/ioccom.h'))
diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index 445966f..ad3ce34 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -720,7 +720,9 @@ static TCGv gen_lea_mode(CPUM68KState *env, DisasContext *s,
         }
         /* fallthru */
     case 2: /* Indirect register */
-        return get_areg(s, reg0);
+        tmp = tcg_temp_new();
+        tcg_gen_mov_i32(tmp, get_areg(s, reg0));
+        return tmp;
     case 4: /* Indirect predecrememnt.  */
         if (opsize == OS_UNSIZED) {
             return NULL_QREG;
@@ -747,20 +749,23 @@ static TCGv gen_lea_mode(CPUM68KState *env, DisasContext *s,
         switch (reg0) {
         case 0: /* Absolute short.  */
             offset = (int16_t)read_im16(env, s);
-            return tcg_constant_i32(offset);
+            break;
         case 1: /* Absolute long.  */
             offset = read_im32(env, s);
-            return tcg_constant_i32(offset);
+            break;
         case 2: /* pc displacement  */
             offset = s->pc;
             offset += (int16_t)read_im16(env, s);
-            return tcg_constant_i32(offset);
+            break;
         case 3: /* pc index+displacement.  */
             return gen_lea_indexed(env, s, NULL_QREG);
         case 4: /* Immediate.  */
         default:
             return NULL_QREG;
         }
+        tmp = tcg_temp_new();
+        tcg_gen_movi_i32(tmp, offset);
+        return tmp;
     }
     /* Should never happen.  */
     return NULL_QREG;
diff --git a/tcg/ppc/tcg-target.c.inc b/tcg/ppc/tcg-target.c.inc
index 3f413ce..223f079 100644
--- a/tcg/ppc/tcg-target.c.inc
+++ b/tcg/ppc/tcg-target.c.inc
@@ -2617,8 +2617,8 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, HostAddress *h,
 
     if (TCG_TARGET_REG_BITS == 64 && addr_type == TCG_TYPE_I32) {
         /* Zero-extend the guest address for use in the host address. */
-        tcg_out_ext32u(s, TCG_REG_R0, addrlo);
-        h->index = TCG_REG_R0;
+        tcg_out_ext32u(s, TCG_REG_TMP2, addrlo);
+        h->index = TCG_REG_TMP2;
     } else {
         h->index = addrlo;
     }
@@ -2704,9 +2704,9 @@ static void tcg_out_qemu_st(TCGContext *s, TCGReg datalo, TCGReg datahi,
         uint32_t insn = qemu_stx_opc[opc & (MO_BSWAP | MO_SIZE)];
         if (!have_isa_2_06 && insn == STDBRX) {
             tcg_out32(s, STWBRX | SAB(datalo, h.base, h.index));
-            tcg_out32(s, ADDI | TAI(TCG_REG_TMP1, h.index, 4));
+            tcg_out32(s, ADDI | TAI(TCG_REG_TMP2, h.index, 4));
             tcg_out_shri64(s, TCG_REG_R0, datalo, 32);
-            tcg_out32(s, STWBRX | SAB(TCG_REG_R0, h.base, TCG_REG_TMP1));
+            tcg_out32(s, STWBRX | SAB(TCG_REG_R0, h.base, TCG_REG_TMP2));
         } else {
             tcg_out32(s, insn | SAB(datalo, h.base, h.index));
         }