[PATCH v4 32/38] linux-user: Add "safe" parameter to do_guest_openat()

["Alex Bennée" <alex.bennee@linaro.org>]

From: Ilya Leoshkevich <iii@linux.ibm.com>

gdbstub cannot meaningfully handle QEMU_ERESTARTSYS, and it doesn't
need to. Add a parameter to do_guest_openat() that makes it use
openat() instead of safe_openat(), so that it becomes usable from
gdbstub.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230621203627.1808446-3-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 linux-user/qemu.h    |  2 +-
 linux-user/syscall.c | 18 +++++++++++++-----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index a5830ec239..9b8e0860d7 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -166,7 +166,7 @@ typedef struct TaskState {
 
 abi_long do_brk(abi_ulong new_brk);
 int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
-                    int flags, mode_t mode);
+                    int flags, mode_t mode, bool safe);
 ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz);
 
 /* user access */
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index fa83737192..ecd9f5e23d 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -8449,7 +8449,7 @@ static int open_hardware(CPUArchState *cpu_env, int fd)
 #endif
 
 int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
-                    int flags, mode_t mode)
+                    int flags, mode_t mode, bool safe)
 {
     struct fake_open {
         const char *filename;
@@ -8476,7 +8476,11 @@ int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
     };
 
     if (is_proc_myself(pathname, "exe")) {
-        return safe_openat(dirfd, exec_path, flags, mode);
+        if (safe) {
+            return safe_openat(dirfd, exec_path, flags, mode);
+        } else {
+            return openat(dirfd, exec_path, flags, mode);
+        }
     }
 
     for (fake_open = fakes; fake_open->filename; fake_open++) {
@@ -8518,7 +8522,11 @@ int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
         return fd;
     }
 
-    return safe_openat(dirfd, path(pathname), flags, mode);
+    if (safe) {
+        return safe_openat(dirfd, path(pathname), flags, mode);
+    } else {
+        return openat(dirfd, path(pathname), flags, mode);
+    }
 }
 
 ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz)
@@ -9027,7 +9035,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
             return -TARGET_EFAULT;
         ret = get_errno(do_guest_openat(cpu_env, AT_FDCWD, p,
                                   target_to_host_bitmask(arg2, fcntl_flags_tbl),
-                                  arg3));
+                                  arg3, true));
         fd_trans_unregister(ret);
         unlock_user(p, arg1, 0);
         return ret;
@@ -9037,7 +9045,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
             return -TARGET_EFAULT;
         ret = get_errno(do_guest_openat(cpu_env, arg1, p,
                                   target_to_host_bitmask(arg3, fcntl_flags_tbl),
-                                  arg4));
+                                  arg4, true));
         fd_trans_unregister(ret);
         unlock_user(p, arg2, 0);
         return ret;
-- 
2.39.2