semihosting: fix handling of errno

This patch fixes the handling of errno by setting the sys_errn
only if error has actually occurred during the semihosting call.
It also fixes few issues where error was not set in the first place.

Change-Id: I2fbe562f3ec5e6220b800de04cd33aa1f409c7a0
Signed-off-by: Marek Vrbka <marek.vrbka@codasip.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7730
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Jan Matyas <jan.matyas@codasip.com>

diff --git a/src/target/semihosting_common.c b/src/target/semihosting_common.c
index 107b6d3edc1ab3f3dd3ffc3298a52d9f9a4f0c53..f7acc6092de688b683bc97aaab6b40781c6a735e 100644 (file)
--- a/src/target/semihosting_common.c
+++ b/src/target/semihosting_common.c
@@ -223,7 +223,10 @@ static ssize_t semihosting_write(struct semihosting *semihosting, int fd, void *
                return semihosting_redirect_write(semihosting, buf, size);
 
        /* default write */
-       return write(fd, buf, size);
+       int result = write(fd, buf, size);
+       if (result == -1)
+               semihosting->sys_errno = errno;
+       return result;
 }
 
 static ssize_t semihosting_redirect_read(struct semihosting *semihosting, void *buf, int size)
@@ -268,7 +271,8 @@ static inline ssize_t semihosting_read(struct semihosting *semihosting, int fd,
 
        /* default read */
        ssize_t result = read(fd, buf, size);
-       semihosting->sys_errno = errno;
+       if (result == -1)
+               semihosting->sys_errno = errno;
 
        return result;
 }
@@ -449,12 +453,7 @@ int semihosting_common(struct target *target)
                                                        (fd == 0) ? "stdin" :
                                                        (fd == 1) ? "stdout" : "stderr");
                                        /* Just pretend success */
-                                       if (semihosting->is_fileio) {
-                                               semihosting->result = 0;
-                                       } else {
-                                               semihosting->result = 0;
-                                               semihosting->sys_errno = 0;
-                                       }
+                                       semihosting->result = 0;
                                        break;
                                }
                                /* Close the descriptor */
@@ -464,7 +463,8 @@ int semihosting_common(struct target *target)
                                        fileio_info->param_1 = fd;
                                } else {
                                        semihosting->result = close(fd);
-                                       semihosting->sys_errno = errno;
+                                       if (semihosting->result == -1)
+                                               semihosting->sys_errno = errno;
                                        LOG_DEBUG("close(%d)=%" PRId64, fd, semihosting->result);
                                }
                        }
@@ -842,7 +842,8 @@ int semihosting_common(struct target *target)
                                int fd = semihosting_get_field(target, 0, fields);
                                // isatty() on Windows may return any non-zero value if fd is a terminal
                                semihosting->result = isatty(fd) ? 1 : 0;
-                               semihosting->sys_errno = errno;
+                               if (semihosting->result == 0)
+                                       semihosting->sys_errno = errno;
                                LOG_DEBUG("isatty(%d)=%" PRId64, fd, semihosting->result);
                        }
                        break;
@@ -934,14 +935,16 @@ int semihosting_common(struct target *target)
                                                        semihosting->result = -1;
                                                        semihosting->sys_errno = EINVAL;
                                                } else if (strcmp((char *)fn, ":tt") == 0) {
-                                                       if (mode == 0)
+                                                       if (mode == 0) {
                                                                semihosting->result = 0;
-                                                       else if (mode == 4)
+                                                       } else if (mode == 4) {
                                                                semihosting->result = 1;
-                                                       else if (mode == 8)
+                                                       } else if (mode == 8) {
                                                                semihosting->result = 2;
-                                                       else
+                                                       } else {
                                                                semihosting->result = -1;
+                                                               semihosting->sys_errno = EINVAL;
+                                                       }
                                                } else {
                                                        semihosting->hit_fileio = true;
                                                        fileio_info->identifier = "open";
@@ -956,25 +959,23 @@ int semihosting_common(struct target *target)
                                                         * - 0-3 ("r") for stdin,
                                                         * - 4-7 ("w") for stdout,
                                                         * - 8-11 ("a") for stderr */
+                                                       int fd;
                                                        if (mode < 4) {
-                                                               int fd = dup(STDIN_FILENO);
-                                                               semihosting->result = fd;
+                                                               fd = dup(STDIN_FILENO);
                                                                semihosting->stdin_fd = fd;
-                                                               semihosting->sys_errno = errno;
-                                                               LOG_DEBUG("dup(STDIN)=%" PRId64, semihosting->result);
+                                                               LOG_DEBUG("dup(STDIN)=%d", fd);
                                                        } else if (mode < 8) {
-                                                               int fd = dup(STDOUT_FILENO);
-                                                               semihosting->result = fd;
+                                                               fd = dup(STDOUT_FILENO);
                                                                semihosting->stdout_fd = fd;
-                                                               semihosting->sys_errno = errno;
-                                                               LOG_DEBUG("dup(STDOUT)=%" PRId64, semihosting->result);
+                                                               LOG_DEBUG("dup(STDOUT)=%d", fd);
                                                        } else {
-                                                               int fd = dup(STDERR_FILENO);
-                                                               semihosting->result = fd;
+                                                               fd = dup(STDERR_FILENO);
                                                                semihosting->stderr_fd = fd;
-                                                               semihosting->sys_errno = errno;
-                                                               LOG_DEBUG("dup(STDERR)=%" PRId64, semihosting->result);
+                                                               LOG_DEBUG("dup(STDERR)=%d", fd);
                                                        }
+                                                       semihosting->result = fd;
+                                                       if (fd == -1)
+                                                               semihosting->sys_errno = errno;
                                                } else {
                                                        /* cygwin requires the permission setting
                                                         * otherwise it will fail to reopen a previously
@@ -982,7 +983,8 @@ int semihosting_common(struct target *target)
                                                        semihosting->result = open((char *)fn,
                                                                        open_host_modeflags[mode],
                                                                        0644);
-                                                       semihosting->sys_errno = errno;
+                                                       if (semihosting->result == -1)
+                                                               semihosting->sys_errno = errno;
                                                        LOG_DEBUG("open('%s')=%" PRId64, fn, semihosting->result);
                                                }
                                        }
@@ -1131,7 +1133,8 @@ int semihosting_common(struct target *target)
                                                }
                                                fn[len] = 0;
                                                semihosting->result = remove((char *)fn);
-                                               semihosting->sys_errno = errno;
+                                               if (semihosting->result == -1)
+                                                       semihosting->sys_errno = errno;
                                                LOG_DEBUG("remove('%s')=%" PRId64, fn, semihosting->result);
 
                                                free(fn);
@@ -1200,7 +1203,9 @@ int semihosting_common(struct target *target)
                                                fn2[len2] = 0;
                                                semihosting->result = rename((char *)fn1,
                                                                (char *)fn2);
-                                               semihosting->sys_errno = errno;
+                                               // rename() on Windows returns nonzero on error
+                                               if (semihosting->result != 0)
+                                                       semihosting->sys_errno = errno;
                                                LOG_DEBUG("rename('%s', '%s')=%" PRId64 " %d", fn1, fn2, semihosting->result, errno);
                                                free(fn1);
                                                free(fn2);
@@ -1245,7 +1250,8 @@ int semihosting_common(struct target *target)
                                        fileio_info->param_3 = SEEK_SET;
                                } else {
                                        semihosting->result = lseek(fd, pos, SEEK_SET);
-                                       semihosting->sys_errno = errno;
+                                       if (semihosting->result == -1)
+                                               semihosting->sys_errno = errno;
                                        LOG_DEBUG("lseek(%d, %d)=%" PRId64, fd, (int)pos, semihosting->result);
                                        if (semihosting->result == pos)
                                                semihosting->result = 0;
@@ -1383,7 +1389,6 @@ int semihosting_common(struct target *target)
                                                        return retval;
                                                }
                                                semihosting->result = semihosting_write(semihosting, fd, buf, len);
-                                               semihosting->sys_errno = errno;
                                                LOG_DEBUG("write(%d, 0x%" PRIx64 ", %zu)=%" PRId64,
                                                        fd,
                                                        addr,
@@ -1671,7 +1676,6 @@ static int semihosting_common_fileio_end(struct target *target, int result,
        semihosting->hit_fileio = false;
 
        semihosting->result = result;
-       semihosting->sys_errno = fileio_errno;
 
        /*
         * Some fileio results do not match up with what the semihosting
@@ -1693,6 +1697,17 @@ static int semihosting_common_fileio_end(struct target *target, int result,
                        break;
        }
 
+       bool fileio_failed = false;
+       if (semihosting->op == SEMIHOSTING_SYS_ISTTY)
+               fileio_failed = (semihosting->result == 0);
+       else if (semihosting->op == SEMIHOSTING_SYS_RENAME)
+               fileio_failed = (semihosting->result != 0);
+       else
+               fileio_failed = (semihosting->result == -1);
+
+       if (fileio_failed)
+               semihosting->sys_errno = fileio_errno;
+
        return semihosting->post_result(target);
 }