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[PATCH v3] Allow using special files with File I/O functions
- From: Julio Guerra <julio at farjump dot io>
- To: gdb-patches at sourceware dot org <gdb-patches at sourceware dot org>
- Cc: Pedro Alves <palves at redhat dot com>, Julio Guerra <julio at farjump dot io>
- Date: Thu, 28 Jun 2018 19:27:01 +0000
- Subject: [PATCH v3] Allow using special files with File I/O functions
- References: <20180628192635.44056-1-julio@farjump.io>
- Remove the restriction to regular files only and add support for special file
types in the File IO stat structure.
- Define a few more macro definitions of file types such as FIFOs, etc.
The major goal is being able to write advanced embedded testing functions, like:
- using a FIFO between the embedded program and the host, instead of being
restricted only to the GDB console.
- mocking features based on host's by opening some /dev special files.
2018-06-28 Julio Guerra <julio@farjump.io>
* remote-fileio.c (remote_fileio_func_open, remote_fileio_func_stat):
Allow using File I/O functions open(), stat() and fstat() on special
files.
* ../include/gdb/fileio.h: Add macro definitions for special files,
both for fst_dev and fst_mode fields of struct fst_stat.
* common/fileio.c (fileio_to_host_mode, fileio_mode_pack): Add new
special file types in fst_mode's definition.
(host_to_fileio_stat): Define fst_dev using the new macro definitions
and according to the file's type.
Signed-off-by: Julio Guerra <julio@farjump.io>
---
gdb/ChangeLog | 12 ++++++++
gdb/common/fileio.c | 66 +++++++++++++++++++++++++++++++++++---------
gdb/remote-fileio.c | 28 ++-----------------
include/gdb/fileio.h | 19 +++++++++++--
4 files changed, 83 insertions(+), 42 deletions(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 18c1915675..19cf5e38a6 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,15 @@
+2018-06-28 Julio Guerra <julio@farjump.io>
+
+ * remote-fileio.c (remote_fileio_func_open, remote_fileio_func_stat):
+ Allow using File I/O functions open(), stat() and fstat() on special
+ files.
+ * ../include/gdb/fileio.h: Add macro definitions for special files,
+ both for fst_dev and fst_mode fields of struct fst_stat.
+ * common/fileio.c (fileio_to_host_mode, fileio_mode_pack): Add new
+ special file types in fst_mode's definition.
+ (host_to_fileio_stat): Define fst_dev using the new macro definitions
+ and according to the file's type.
+
2018-06-27 Simon Marchi <simon.marchi@ericsson.com>
* gdb-gdb.py.in (StructMainTypePrettyPrinter) <to_string>: Don't
diff --git a/gdb/common/fileio.c b/gdb/common/fileio.c
index 912a7ede3c..9ee78e227c 100644
--- a/gdb/common/fileio.c
+++ b/gdb/common/fileio.c
@@ -119,12 +119,31 @@ fileio_to_host_mode (int fileio_mode, mode_t *mode_p)
if (fileio_mode & ~FILEIO_S_SUPPORTED)
return -1;
- if (fileio_mode & FILEIO_S_IFREG)
- mode |= S_IFREG;
- if (fileio_mode & FILEIO_S_IFDIR)
- mode |= S_IFDIR;
- if (fileio_mode & FILEIO_S_IFCHR)
- mode |= S_IFCHR;
+ switch (fileio_mode & FILEIO_S_IFMT)
+ {
+ case FILEIO_S_IFSOCK:
+ *mode_p |= S_IFSOCK;
+ break;
+ case FILEIO_S_IFLNK:
+ mode |= S_IFLNK;
+ break;
+ case FILEIO_S_IFREG:
+ mode |= S_IFREG;
+ break;
+ case FILEIO_S_IFBLK:
+ mode |= S_IFBLK;
+ break;
+ case FILEIO_S_IFDIR:
+ mode |= S_IFDIR;
+ break;
+ case FILEIO_S_IFCHR:
+ mode |= S_IFCHR;
+ break;
+ case FILEIO_S_IFIFO:
+ mode |= S_IFIFO;
+ break;
+ }
+
if (fileio_mode & FILEIO_S_IRUSR)
mode |= S_IRUSR;
if (fileio_mode & FILEIO_S_IWUSR)
@@ -165,12 +184,31 @@ fileio_mode_pack (mode_t mode)
{
mode_t tmode = 0;
- if (S_ISREG (mode))
- tmode |= FILEIO_S_IFREG;
- if (S_ISDIR (mode))
- tmode |= FILEIO_S_IFDIR;
- if (S_ISCHR (mode))
- tmode |= FILEIO_S_IFCHR;
+ switch (mode & S_IFMT)
+ {
+ case S_IFSOCK:
+ tmode |= FILEIO_S_IFSOCK;
+ break;
+ case S_IFLNK:
+ tmode |= FILEIO_S_IFLNK;
+ break;
+ case S_IFREG:
+ tmode |= FILEIO_S_IFREG;
+ break;
+ case S_IFBLK:
+ tmode |= FILEIO_S_IFBLK;
+ break;
+ case S_IFDIR:
+ tmode |= FILEIO_S_IFDIR;
+ break;
+ case S_IFCHR:
+ tmode |= FILEIO_S_IFCHR;
+ break;
+ case S_IFIFO:
+ tmode |= FILEIO_S_IFIFO;
+ break;
+ }
+
if (mode & S_IRUSR)
tmode |= FILEIO_S_IRUSR;
if (mode & S_IWUSR)
@@ -224,8 +262,10 @@ void
host_to_fileio_stat (struct stat *st, struct fio_stat *fst)
{
LONGEST blksize;
+ long fst_dev;
- host_to_fileio_uint ((long) st->st_dev, fst->fst_dev);
+ fst_dev = S_ISREG(st->st_mode) ? FILEIO_STDEV_FILE : FILEIO_STDEV_SPECIAL;
+ host_to_fileio_uint (fst_dev, fst->fst_dev);
host_to_fileio_uint ((long) st->st_ino, fst->fst_ino);
host_to_fileio_mode (st->st_mode, fst->fst_mode);
host_to_fileio_uint ((long) st->st_nlink, fst->fst_nlink);
diff --git a/gdb/remote-fileio.c b/gdb/remote-fileio.c
index 313da642ea..837081269a 100644
--- a/gdb/remote-fileio.c
+++ b/gdb/remote-fileio.c
@@ -407,24 +407,6 @@ remote_fileio_func_open (remote_target *remote, char *buf)
return;
}
- /* Check if pathname exists and is not a regular file or directory. If so,
- return an appropriate error code. Same for trying to open directories
- for writing. */
- if (!stat (pathname, &st))
- {
- if (!S_ISREG (st.st_mode) && !S_ISDIR (st.st_mode))
- {
- remote_fileio_reply (remote, -1, FILEIO_ENODEV);
- return;
- }
- if (S_ISDIR (st.st_mode)
- && ((flags & O_WRONLY) == O_WRONLY || (flags & O_RDWR) == O_RDWR))
- {
- remote_fileio_reply (remote, -1, FILEIO_EISDIR);
- return;
- }
- }
-
fd = gdb_open_cloexec (pathname, flags, mode);
if (fd < 0)
{
@@ -885,16 +867,9 @@ remote_fileio_func_stat (remote_target *remote, char *buf)
remote_fileio_return_errno (remote, -1);
return;
}
- /* Only operate on regular files and directories. */
- if (!ret && !S_ISREG (st.st_mode) && !S_ISDIR (st.st_mode))
- {
- remote_fileio_reply (remote, -1, FILEIO_EACCES);
- return;
- }
if (statptr)
{
host_to_fileio_stat (&st, &fst);
- host_to_fileio_uint (0, fst.fst_dev);
errno = target_write_memory (statptr, (gdb_byte *) &fst, sizeof fst);
if (errno != 0)
@@ -939,7 +914,6 @@ remote_fileio_func_fstat (remote_target *remote, char *buf)
if (fd == FIO_FD_CONSOLE_IN || fd == FIO_FD_CONSOLE_OUT)
{
- host_to_fileio_uint (1, fst.fst_dev);
memset (&st, 0, sizeof (st));
st.st_mode = S_IFCHR | (fd == FIO_FD_CONSOLE_IN ? S_IRUSR : S_IWUSR);
st.st_nlink = 1;
@@ -972,6 +946,8 @@ remote_fileio_func_fstat (remote_target *remote, char *buf)
if (ptrval)
{
host_to_fileio_stat (&st, &fst);
+ if (fd == FIO_FD_CONSOLE_IN || fd == FIO_FD_CONSOLE_OUT)
+ host_to_fileio_uint (FILEIO_STDEV_CONSOLE, fst.fst_dev);
errno = target_write_memory (ptrval, (gdb_byte *) &fst, sizeof fst);
if (errno != 0)
diff --git a/include/gdb/fileio.h b/include/gdb/fileio.h
index 7bb55f579f..ada84c5f10 100644
--- a/include/gdb/fileio.h
+++ b/include/gdb/fileio.h
@@ -37,10 +37,24 @@
FILEIO_O_CREAT | FILEIO_O_TRUNC| \
FILEIO_O_EXCL)
+/* Device id values of fst_dev field */
+/* Regular file */
+#define FILEIO_STDEV_FILE 0
+/* GDB's console */
+#define FILEIO_STDEV_CONSOLE 1
+/* Not a regular file nor the console.
+ Bits FILEIO_S_IFMT of fst_mode give the exact file type. */
+#define FILEIO_STDEV_SPECIAL 2
+
/* mode_t bits */
+#define FILEIO_S_IFSOCK 0140000
+#define FILEIO_S_IFLNK 0120000
#define FILEIO_S_IFREG 0100000
+#define FILEIO_S_IFBLK 060000
#define FILEIO_S_IFDIR 040000
#define FILEIO_S_IFCHR 020000
+#define FILEIO_S_IFIFO 010000
+#define FILEIO_S_IFMT 0170000
#define FILEIO_S_IRUSR 0400
#define FILEIO_S_IWUSR 0200
#define FILEIO_S_IXUSR 0100
@@ -53,9 +67,8 @@
#define FILEIO_S_IWOTH 02
#define FILEIO_S_IXOTH 01
#define FILEIO_S_IRWXO 07
-#define FILEIO_S_SUPPORTED (FILEIO_S_IFREG|FILEIO_S_IFDIR| \
- FILEIO_S_IRWXU|FILEIO_S_IRWXG| \
- FILEIO_S_IRWXO)
+#define FILEIO_S_SUPPORTED (FILEIO_S_IFMT | FILEIO_S_IRWXU| \
+ FILEIO_S_IRWXG | FILEIO_S_IRWXO)
/* lseek(2) flags */
#define FILEIO_SEEK_SET 0
--
2.18.0