user: add errno-based syscall wrappers

diff --git a/Makefile b/Makefile
index 02b67abddbd6cf1602d85f5fd9ef60dd919208a8..f635b928e63e6e10cd7c79ef921eb659a86ded45 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -119,10 +119,10 @@ $(MKINITRD): tools/mkinitrd.c
        @gcc tools/mkinitrd.c -o $(MKINITRD)
 
 $(USER_ELF): user/init.c user/linker.ld
-       @i686-elf-gcc -m32 -ffreestanding -fno-pie -no-pie -nostdlib -Wl,-T,user/linker.ld -o $(USER_ELF) user/init.c
+       @i686-elf-gcc -m32 -ffreestanding -fno-pie -no-pie -nostdlib -Wl,-T,user/linker.ld -o $(USER_ELF) user/init.c user/errno.c
 
 $(ECHO_ELF): user/echo.c user/linker.ld
-       @i686-elf-gcc -m32 -ffreestanding -fno-pie -no-pie -nostdlib -Wl,-T,user/linker.ld -o $(ECHO_ELF) user/echo.c
+       @i686-elf-gcc -m32 -ffreestanding -fno-pie -no-pie -nostdlib -Wl,-T,user/linker.ld -o $(ECHO_ELF) user/echo.c user/errno.c
 
 $(INITRD_IMG): $(MKINITRD) $(USER_ELF) $(ECHO_ELF)
        @./$(MKINITRD) $(INITRD_IMG) $(USER_ELF):bin/init.elf $(ECHO_ELF):bin/echo.elf

diff --git a/user/echo.c b/user/echo.c
index 2c70ea08aba021704e7b4bd74f51080482950318..a9b19fa3a405dca3adca6c85ad5f3cfb981f37ba 100644 (file)
--- a/user/echo.c
+++ b/user/echo.c
@@ -1,5 +1,7 @@
 #include <stdint.h>
 
+#include "user_errno.h"
+
 enum {
     SYSCALL_WRITE = 1,
     SYSCALL_EXIT  = 2,
@@ -13,7 +15,7 @@ static int sys_write(int fd, const void* buf, uint32_t len) {
         : "a"(SYSCALL_WRITE), "b"(fd), "c"(buf), "d"(len)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static uint32_t ustrlen(const char* s) {

diff --git a/user/errno.c b/user/errno.c
new file mode 100644 (file)
index 0000000..8330a8f
--- /dev/null
+++ b/user/errno.c
@@ -0,0 +1 @@
+int errno = 0;

diff --git a/user/init.c b/user/init.c
index 86ccfdb886315c738ea75f0b5ac4f6411ec17cdc..8988b69f5615e0d28a5c90de588530ed2e734643 100644 (file)
--- a/user/init.c
+++ b/user/init.c
@@ -29,6 +29,8 @@
 #undef SEEK_END
 #endif
 
+#include "user_errno.h"
+
 enum {
     SYSCALL_WRITE = 1,
     SYSCALL_EXIT  = 2,
@@ -123,7 +125,7 @@ static int sys_write(int fd, const void* buf, uint32_t len) {
         : "a"(SYSCALL_WRITE), "b"(fd), "c"(buf), "d"(len)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static void write_int_dec(int v) {
@@ -179,7 +181,7 @@ static int sys_sigaction(int sig, void (*handler)(int), uintptr_t* old_out) {
         : "a"(SYSCALL_SIGACTION), "b"(sig), "c"(handler), "d"(old_out)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_select(uint32_t nfds, uint64_t* readfds, uint64_t* writefds, uint64_t* exceptfds, int32_t timeout) {
@@ -190,7 +192,7 @@ static int sys_select(uint32_t nfds, uint64_t* readfds, uint64_t* writefds, uint
         : "a"(SYSCALL_SELECT), "b"(nfds), "c"(readfds), "d"(writefds), "S"(exceptfds), "D"(timeout)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_ioctl(int fd, uint32_t cmd, void* arg) {
@@ -201,7 +203,7 @@ static int sys_ioctl(int fd, uint32_t cmd, void* arg) {
         : "a"(SYSCALL_IOCTL), "b"(fd), "c"(cmd), "d"(arg)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_kill(int pid, int sig) {
@@ -212,7 +214,7 @@ static int sys_kill(int pid, int sig) {
         : "a"(SYSCALL_KILL), "b"(pid), "c"(sig)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_poll(struct pollfd* fds, uint32_t nfds, int32_t timeout) {
@@ -223,7 +225,7 @@ static int sys_poll(struct pollfd* fds, uint32_t nfds, int32_t timeout) {
         : "a"(SYSCALL_POLL), "b"(fds), "c"(nfds), "d"(timeout)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_setsid(void) {
@@ -234,7 +236,7 @@ static int sys_setsid(void) {
         : "a"(SYSCALL_SETSID)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_setpgid(int pid, int pgid) {
@@ -245,7 +247,7 @@ static int sys_setpgid(int pid, int pgid) {
         : "a"(SYSCALL_SETPGID), "b"(pid), "c"(pgid)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_getpgrp(void) {
@@ -256,7 +258,7 @@ static int sys_getpgrp(void) {
         : "a"(SYSCALL_GETPGRP)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_getpid(void) {
@@ -267,7 +269,7 @@ static int sys_getpid(void) {
         : "a"(SYSCALL_GETPID)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_getppid(void) {
@@ -278,7 +280,7 @@ static int sys_getppid(void) {
         : "a"(SYSCALL_GETPPID)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_fork(void) {
@@ -289,7 +291,7 @@ static int sys_fork(void) {
         : "a"(SYSCALL_FORK)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_execve(const char* path, const char* const* argv, const char* const* envp) {
@@ -300,7 +302,7 @@ static int sys_execve(const char* path, const char* const* argv, const char* con
         : "a"(SYSCALL_EXECVE), "b"(path), "c"(argv), "d"(envp)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_pipe(int fds[2]) {
@@ -311,7 +313,7 @@ static int sys_pipe(int fds[2]) {
         : "a"(SYSCALL_PIPE), "b"(fds)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_dup(int oldfd) {
@@ -322,7 +324,7 @@ static int sys_dup(int oldfd) {
         : "a"(SYSCALL_DUP), "b"(oldfd)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_dup2(int oldfd, int newfd) {
@@ -333,7 +335,7 @@ static int sys_dup2(int oldfd, int newfd) {
         : "a"(SYSCALL_DUP2), "b"(oldfd), "c"(newfd)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_waitpid(int pid, int* status, uint32_t options) {
@@ -344,7 +346,7 @@ static int sys_waitpid(int pid, int* status, uint32_t options) {
         : "a"(SYSCALL_WAITPID), "b"(pid), "c"(status), "d"(options)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_open(const char* path, uint32_t flags) {
@@ -355,7 +357,7 @@ static int sys_open(const char* path, uint32_t flags) {
         : "a"(SYSCALL_OPEN), "b"(path), "c"(flags)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_read(int fd, void* buf, uint32_t len) {
@@ -366,7 +368,7 @@ static int sys_read(int fd, void* buf, uint32_t len) {
         : "a"(SYSCALL_READ), "b"(fd), "c"(buf), "d"(len)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_close(int fd) {
@@ -377,7 +379,7 @@ static int sys_close(int fd) {
         : "a"(SYSCALL_CLOSE), "b"(fd)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_lseek(int fd, int32_t offset, int whence) {
@@ -388,7 +390,7 @@ static int sys_lseek(int fd, int32_t offset, int whence) {
         : "a"(SYSCALL_LSEEK), "b"(fd), "c"(offset), "d"(whence)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_fstat(int fd, struct stat* st) {
@@ -399,7 +401,7 @@ static int sys_fstat(int fd, struct stat* st) {
         : "a"(SYSCALL_FSTAT), "b"(fd), "c"(st)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 static int sys_stat(const char* path, struct stat* st) {
@@ -410,7 +412,7 @@ static int sys_stat(const char* path, struct stat* st) {
         : "a"(SYSCALL_STAT), "b"(path), "c"(st)
         : "memory"
     );
-    return ret;
+    return __syscall_fix(ret);
 }
 
 __attribute__((noreturn)) static void sys_exit(int code) {

diff --git a/user/user_errno.h b/user/user_errno.h
new file mode 100644 (file)
index 0000000..6681cc9
--- /dev/null
+++ b/user/user_errno.h
@@ -0,0 +1,14 @@
+#ifndef USER_ERRNO_H
+#define USER_ERRNO_H
+
+extern int errno;
+
+static inline int __syscall_fix(int ret) {
+    if (ret < 0) {
+        errno = -ret;
+        return -1;
+    }
+    return ret;
+}
+
+#endif