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From: "Paul E. McKenney" <[email protected]>
To: [email protected]
Cc: [email protected], [email protected], [email protected],
	"Thomas Weißschuh" <[email protected]>,
	"Willy Tarreau" <[email protected]>,
	"Paul E . McKenney" <[email protected]>
Subject: [PATCH v2 nolibc 06/15] tools/nolibc: implement fd-based FILE streams
Date: Thu, 18 May 2023 07:55:12 -0700	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <4817a4dc-69e6-4937-84d5-f2f630ff646c@paulmck-laptop>

From: Thomas Weißschuh <[email protected]>

This enables the usage of the stream APIs with arbitrary filedescriptors.

It will be used by a future testcase.

Signed-off-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Willy Tarreau <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
---
 tools/include/nolibc/stdio.h | 95 ++++++++++++++++++++++++++----------
 1 file changed, 68 insertions(+), 27 deletions(-)

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 6cbbb52836a0..0eef91daf289 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -21,17 +21,75 @@
 #define EOF (-1)
 #endif
 
-/* just define FILE as a non-empty type */
+/* just define FILE as a non-empty type. The value of the pointer gives
+ * the FD: FILE=~fd for fd>=0 or NULL for fd<0. This way positive FILE
+ * are immediately identified as abnormal entries (i.e. possible copies
+ * of valid pointers to something else).
+ */
 typedef struct FILE {
 	char dummy[1];
 } FILE;
 
-/* We define the 3 common stdio files as constant invalid pointers that
- * are easily recognized.
- */
-static __attribute__((unused)) FILE* const stdin  = (FILE*)-3;
-static __attribute__((unused)) FILE* const stdout = (FILE*)-2;
-static __attribute__((unused)) FILE* const stderr = (FILE*)-1;
+static __attribute__((unused)) FILE* const stdin  = (FILE*)(intptr_t)~STDIN_FILENO;
+static __attribute__((unused)) FILE* const stdout = (FILE*)(intptr_t)~STDOUT_FILENO;
+static __attribute__((unused)) FILE* const stderr = (FILE*)(intptr_t)~STDERR_FILENO;
+
+/* provides a FILE* equivalent of fd. The mode is ignored. */
+static __attribute__((unused))
+FILE *fdopen(int fd, const char *mode __attribute__((unused)))
+{
+	if (fd < 0) {
+		SET_ERRNO(EBADF);
+		return NULL;
+	}
+	return (FILE*)(intptr_t)~fd;
+}
+
+/* provides the fd of stream. */
+static __attribute__((unused))
+int fileno(FILE *stream)
+{
+	intptr_t i = (intptr_t)stream;
+
+	if (i >= 0) {
+		SET_ERRNO(EBADF);
+		return -1;
+	}
+	return ~i;
+}
+
+/* flush a stream. */
+static __attribute__((unused))
+int fflush(FILE *stream)
+{
+	intptr_t i = (intptr_t)stream;
+
+	/* NULL is valid here. */
+	if (i > 0) {
+		SET_ERRNO(EBADF);
+		return -1;
+	}
+
+	/* Don't do anything, nolibc does not support buffering. */
+	return 0;
+}
+
+/* flush a stream. */
+static __attribute__((unused))
+int fclose(FILE *stream)
+{
+	intptr_t i = (intptr_t)stream;
+
+	if (i >= 0) {
+		SET_ERRNO(EBADF);
+		return -1;
+	}
+
+	if (close(~i))
+		return EOF;
+
+	return 0;
+}
 
 /* getc(), fgetc(), getchar() */
 
@@ -41,14 +99,8 @@ static __attribute__((unused))
 int fgetc(FILE* stream)
 {
 	unsigned char ch;
-	int fd;
 
-	if (stream < stdin || stream > stderr)
-		return EOF;
-
-	fd = 3 + (long)stream;
-
-	if (read(fd, &ch, 1) <= 0)
+	if (read(fileno(stream), &ch, 1) <= 0)
 		return EOF;
 	return ch;
 }
@@ -68,14 +120,8 @@ static __attribute__((unused))
 int fputc(int c, FILE* stream)
 {
 	unsigned char ch = c;
-	int fd;
-
-	if (stream < stdin || stream > stderr)
-		return EOF;
-
-	fd = 3 + (long)stream;
 
-	if (write(fd, &ch, 1) <= 0)
+	if (write(fileno(stream), &ch, 1) <= 0)
 		return EOF;
 	return ch;
 }
@@ -96,12 +142,7 @@ static __attribute__((unused))
 int _fwrite(const void *buf, size_t size, FILE *stream)
 {
 	ssize_t ret;
-	int fd;
-
-	if (stream < stdin || stream > stderr)
-		return EOF;
-
-	fd = 3 + (long)stream;
+	int fd = fileno(stream);
 
 	while (size) {
 		ret = write(fd, buf, size);
-- 
2.40.1


  parent reply	other threads:[~2023-05-18 14:55 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-18 14:55 [PATCH nolibc 0/15] nolibc updates for v6.5] Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 01/15] tools/nolibc: tests: use volatile to force stack smashing Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 02/15] tools/nolibc: tests: fix build on non-c99 compliant compilers Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 03/15] tools/nolibc: fix build of the test case using glibc Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 04/15] tools/nolibc: add libc-test binary Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 05/15] tools/nolibc: add wrapper for memfd_create Paul E. McKenney
2023-05-18 14:55 ` Paul E. McKenney [this message]
2023-05-18 14:55 ` [PATCH v2 nolibc 07/15] tools/nolibc: add testcases for vfprintf Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 08/15] tools/nolibc: Fix build of stdio.h due to header ordering Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 09/15] tools/nolibc: use standard __asm__ statements Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 10/15] tools/nolibc: use __inline__ syntax Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 11/15] tools/nolibc: use C89 comment syntax Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 12/15] tools/nolibc: validate C89 compatibility Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 13/15] tools/nolibc: s390: provide custom implementation for sys_fork Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 14/15] tools/nolibc: add testcase for fork()/waitpid() Paul E. McKenney
2023-05-18 14:55 ` [PATCH v2 nolibc 15/15] tools/nolibc: remove LINUX_REBOOT_ constants Paul E. McKenney
2023-06-12 20:44 ` [PATCH v2 nolibc 0/15] nolibc updates for v6.5] Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 01/53] tools/nolibc: tests: use volatile to force stack smashing Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 02/53] tools/nolibc: tests: fix build on non-c99 compliant compilers Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 03/53] tools/nolibc: fix build of the test case using glibc Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 04/53] tools/nolibc: add libc-test binary Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 05/53] tools/nolibc: add wrapper for memfd_create Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 06/53] tools/nolibc: implement fd-based FILE streams Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 07/53] tools/nolibc: add testcases for vfprintf Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 08/53] tools/nolibc: Fix build of stdio.h due to header ordering Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 09/53] tools/nolibc: use standard __asm__ statements Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 10/53] tools/nolibc: use __inline__ syntax Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 11/53] tools/nolibc: use C89 comment syntax Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 12/53] tools/nolibc: validate C89 compatibility Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 13/53] tools/nolibc: s390: provide custom implementation for sys_fork Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 14/53] tools/nolibc: add testcase for fork()/waitpid() Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 15/53] tools/nolibc: remove LINUX_REBOOT_ constants Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 16/53] tools/nolibc: riscv: Fix up load/store instructions for rv32 Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 17/53] tools/nolibc/unistd: add syscall() Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 18/53] selftests/nolibc: syscall_args: use generic __NR_statx Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 19/53] selftests/nolibc: reduce syscalls during space padding Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 20/53] tools/nolibc: aarch64: add stackprotector support Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 21/53] tools/nolibc: arm: " Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 22/53] tools/nolibc: loongarch: " Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 23/53] tools/nolibc: mips: " Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 24/53] tools/nolibc: riscv: " Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 25/53] tools/nolibc: fix typo pint -> point Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 26/53] tools/nolibc: x86_64: disable stack protector for _start Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 27/53] tools/nolibc: ensure stack protector guard is never zero Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 28/53] tools/nolibc: add test for __stack_chk_guard initialization Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 29/53] tools/nolibc: reformat list of headers to be installed Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 30/53] tools/nolibc: add autodetection for stackprotector support Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 31/53] tools/nolibc: simplify stackprotector compiler flags Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 32/53] tools/nolibc: fix segfaults on compilers without attribute no_stack_protector Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 33/53] tools/nolibc: s390: disable stackprotector in _start Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 34/53] tools/nolibc: add support for prctl() Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 35/53] selftests/nolibc: prevent coredumps during test execution Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 36/53] tools/nolibc: support nanoseconds in stat() Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 37/53] selftests/nolibc: print name instead of number for EOVERFLOW Paul E. McKenney
2023-06-12 20:44   ` [PATCH v2 nolibc 38/53] selftests/nolibc: remove the duplicated gettimeofday_bad2 Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 39/53] tools/nolibc: ppoll/ppoll_time64: add a missing argument Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 40/53] selftests/nolibc: test_fork: fix up duplicated print Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 41/53] tools/nolibc: ensure fast64 integer types have 64 bits Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 42/53] selftests/nolibc: remove test gettimeofday_null Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 43/53] selftests/nolibc: allow specify extra arguments for qemu Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 44/53] selftests/nolibc: fix up compile warning with glibc on x86_64 Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 45/53] selftests/nolibc: not include limits.h for nolibc Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 46/53] selftests/nolibc: use INT_MAX instead of __INT_MAX__ Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 47/53] tools/nolibc: arm: add missing my_syscall6 Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 48/53] tools/nolibc: open: fix up compile warning for arm Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 49/53] selftests/nolibc: support two errnos with EXPECT_SYSER2() Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 50/53] selftests/nolibc: remove gettimeofday_bad1/2 completely Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 51/53] selftests/nolibc: add new gettimeofday test cases Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 52/53] selftests/nolibc: also count skipped and failed tests in output Paul E. McKenney
2023-06-12 20:45   ` [PATCH v2 nolibc 53/53] selftests/nolibc: make sure gcc always use little endian on MIPS Paul E. McKenney

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