--- /dev/null
+#include <signal.h>
+#include "libsys.h"
+
+int sigprocmask(int flags, const sigset_t *new, sigset_t *old)
+{
+ return _syscall(__NR_sigprocmask, flags, (quad) new, (quad) old);
+}
extern off_t lseek(int fildes, off_t offset, int whence);
extern int fcntl(int fd, int op, ...);
extern int unlink(const char* path);
-extern int remove(const char* path);
/* Special variables */
#define _NSIG 32 /* Biggest signal number + 1
(not including real-time signals). */
+
+/* sigprocmask */
+#define SIG_BLOCK 0
+#define SIG_UNBLOCK 1
+#define SIG_SETMASK 2
+typedef unsigned long sigset_t;
+
typedef void (*sighandler_t)(int);
extern sighandler_t signal(int signum, sighandler_t handler);
+extern int sigprocmask(int, const sigset_t *, sigset_t *);
extern int raise(int signum);
extern int write(int fd, void* buffer, size_t count);
extern off_t lseek(int fildes, off_t offset, int whence);
extern int fcntl(int fd, int op, ...);
+extern int unlink(const char* path);
/* Special variables */
extern int brk(void* ptr);
extern void* sbrk(int increment);
extern int isatty(int d);
+extern int execve(const char *path, char *const argv[], char *const envp[]);
/* Signal handling */
#define _NSIG 32 /* Biggest signal number + 1
(not including real-time signals). */
+
+/* sigprocmask */
+#define SIG_BLOCK 0
+#define SIG_UNBLOCK 1
+#define SIG_SETMASK 2
+typedef unsigned long sigset_t;
+
typedef void (*sighandler_t)(int);
extern sighandler_t signal(int signum, sighandler_t handler);
+extern int sigprocmask(int, const sigset_t *, sigset_t *);
extern int raise(int signum);
extern int write(int fd, void* buffer, size_t count);
extern off_t lseek(int fildes, off_t offset, int whence);
extern int fcntl(int fd, int op, ...);
+extern int unlink(const char* path);
/* Special variables */
#define _NSIG 32 /* Biggest signal number + 1
(not including real-time signals). */
+
+/* sigprocmask */
+#define SIG_BLOCK 0
+#define SIG_UNBLOCK 1
+#define SIG_SETMASK 2
+typedef unsigned long sigset_t;
+
+/* sa_flags */
+#define SA_NODEFER 0x40000000UL
+#define SA_RESETHAND 0x80000000UL
+
+struct __siginfo;
+struct sigaction {
+ union {
+ void (*__sa_handler)(int);
+ void (*__sa_sigaction)(int, struct __siginfo *, void *);
+ } __sigaction_u;
+ sigset_t sa_mask;
+ unsigned long sa_flags;
+ void (*sa_restorer)(void);
+};
+#define sa_handler __sigaction_u.__sa_handler
+#define sa_sigaction __sigaction_u.__sa_sigaction
+
typedef void (*sighandler_t)(int);
+extern int sigaction(int, const struct sigaction *, struct sigaction *);
extern sighandler_t signal(int signum, sighandler_t handler);
+extern int sigprocmask(int, const sigset_t *, sigset_t *);
extern int raise(int signum);
acklibrary {
- name = "lib",
- srcs = {
- "./*.s",
- "plat/linux/libsys/*.c",
- "plat/linux/libsys/*.s",
- },
+ name = "lib",
+ srcs = {
+ "./_syscall.s",
+ "./sigaction.s",
+ "./signal.c",
+ "./trap.s",
+ "plat/linux/libsys/_exit.c",
+ "plat/linux/libsys/_hol0.s",
+ "plat/linux/libsys/close.c",
+ "plat/linux/libsys/creat.c",
+ "plat/linux/libsys/errno.s",
+ "plat/linux/libsys/execve.c",
+ "plat/linux/libsys/getpid.c",
+ "plat/linux/libsys/gettimeofday.c",
+ "plat/linux/libsys/ioctl.c",
+ "plat/linux/libsys/isatty.c",
+ "plat/linux/libsys/kill.c",
+ "plat/linux/libsys/lseek.c",
+ "plat/linux/libsys/open.c",
+ "plat/linux/libsys/read.c",
+ "plat/linux/libsys/sbrk.c",
+ -- omit signal.c
+ "plat/linux/libsys/sigprocmask.c",
+ "plat/linux/libsys/unlink.c",
+ "plat/linux/libsys/write.c",
+ },
deps = {
"lang/cem/libcc.ansi/headers+headers",
"plat/linuxppc/include+headers",
},
- vars = {
- plat = "linuxppc"
- }
+ vars = {
+ plat = "linuxppc"
+ }
}
--- /dev/null
+#define __NR_sigaction 67
+#define SIG_BLOCK 0
+#define SIG_SETMASK 2
+#define MAXSIG 32
+
+/* offsets into our stack frame */
+#define mynew 16 /* new sigaction */
+#define mynset 32 /* new signal set */
+#define myoset 36 /* old signal set */
+#define mysave 40
+#define mysize 56
+
+.sect .text; .sect .rodata; .sect .data; .sect .bss
+
+/*
+ * Linux calls signal handlers with arguments in registers, but the
+ * ACK expects arguments on the stack. This sigaction() uses a
+ * "bridge" to move the arguments.
+ */
+.sect .text
+.define _sigaction
+_sigaction:
+ mflr r0
+ subi r1, r1, mysize
+ stw r31, mysave+8(r1)
+ stw r30, mysave+4(r1)
+ stw r29, mysave(r1)
+ stw r0, mysave+12(r1)
+ li r3, 0
+ stw r3, mynset(r1) ! mynset = 0
+ lwz r29, mysize(r1) ! r29 = signal number
+ lwz r30, mysize+4(r1) ! r30 = new action
+ lwz r31, mysize+8(r1) ! r31 = old action
+ /*
+ * If the new action is non-NULL, the signal number is in
+ * range 1 to MAXSIG, and the new handler is not SIG_DFL 0
+ * or SIG_IGN 1, then we interpose our bridge.
+ */
+ cmpwi cr0, r30, 0
+ subi r7, r29, 1 ! r7 = index in handlers
+ cmplwi cr7, r7, MAXSIG ! unsigned comparison
+ beq cr0, kernel
+ bge cr7, kernel
+ lwz r3, 0(r30) ! r3 = new handler
+ clrrwi. r3, r3, 1
+ beq cr0, kernel
+ /*
+ * Block the signal while we build the bridge. Prevents a
+ * race if a signal arrives after we change the bridge but
+ * before we change the action in the kernel.
+ */
+ li r4, 1
+ slw r4, r4, r7
+ stw r4, mynset(r1) ! mynmask = 1 << (signal - 1)
+ li r3, SIG_BLOCK
+ la r4, mynset(r1)
+ la r5, myoset(r1)
+ stw r3, 0(r1)
+ stw r4, 4(r1)
+ stw r5, 8(r1)
+ bl _sigprocmask
+ /*
+ * Point our bridge to the new signal handler. Then copy the
+ * new sigaction but point it to our bridge.
+ */
+ lis r6, hi16[handlers]
+ ori r6, r6, lo16[handlers]
+ subi r7, r29, 1
+ slwi r7, r7, 2
+ lwz r3, 0(r30) ! r3 = new handler
+ stwx r3, r6, r7 ! put it in array of handlers
+ lis r3, hi16[bridge]
+ ori r3, r3, lo16[bridge]
+ lwz r4, 4(r30)
+ lwz r5, 8(r30)
+ lwz r6, 12(r30)
+ stw r3, mynew(r1) ! sa_handler or sa_sigaction
+ stw r4, mynew+4(r1) ! sa_mask
+ stw r5, mynew+8(r1) ! sa_flags
+ stw r6, mynew+12(r1) ! sa_restorer
+ la r30, mynew(r1)
+kernel:
+ li r3, __NR_sigaction
+ stw r3, 0(r1)
+ stw r29, 4(r1)
+ stw r30, 8(r1)
+ stw r31, 12(r1)
+ bl __syscall
+ /*
+ * If we blocked the signal, then restore the old signal mask.
+ */
+ lwz r3, mynset(r1)
+ cmpwi cr0, r3, 0
+ beq cr0, fixold
+ li r3, SIG_SETMASK
+ la r4, myoset(r1)
+ li r5, 0
+ stw r3, 0(r1)
+ stw r4, 4(r1)
+ stw r5, 8(r1)
+ bl _sigprocmask
+ /*
+ * If the old sigaction is non-NULL and points to our bridge,
+ * then point it to the signal handler.
+ */
+fixold:
+ cmpwi cr0, r31, 0
+ beq cr0, leave
+ lis r3, hi16[bridge]
+ ori r3, r3, lo16[bridge]
+ lwz r4, 0(r31)
+ cmpw cr0, r3, r4
+ bne cr0, leave
+ lis r6, hi16[handlers]
+ ori r6, r6, lo16[handlers]
+ subi r7, r29, 1
+ slwi r7, r7, 2
+ lwzx r3, r6, r7 ! get it from array of handlers
+ stw r3, 0(r31) ! put it in old sigaction
+leave:
+ lwz r0, mysave+12(r1)
+ lwz r29, mysave(r1)
+ lwz r30, mysave+4(r1)
+ lwz r31, mysave+8(r1)
+ addi r1, r1, mysize
+ mtlr r0
+ blr ! return from sigaction
+
+/*
+ * Linux calls bridge(signum) or bridge(signum, info, context) with
+ * arguments in registers r3, r4, r5.
+ */
+bridge:
+ mflr r0
+ subi r1, r1, 16
+ stw r0, 12(r1)
+ stw r3, 0(r1) ! signal number
+ stw r4, 4(r1) ! info
+ stw r5, 8(r1) ! context
+
+ lis r6, hi16[handlers]
+ ori r6, r6, lo16[handlers]
+ subi r7, r3, 1
+ slwi r7, r7, 2
+ lwzx r6, r6, r7
+ mtctr r6
+ bctrl ! call our signal handler
+
+ lwz r0, 12(r1)
+ addi r1, r1, 16
+ mtlr r0
+ blr ! return from bridge
+
+.sect .bss
+handlers:
+ .space 4 * MAXSIG ! array of signal handlers
--- /dev/null
+#include <signal.h>
+
+/*
+ * Uses our bridge in sigaction.s when calling the signal handler.
+ * Mimics Linux __NR_signal by using SA_NODEFER | SA_RESETHAND.
+ */
+sighandler_t signal(int signum, sighandler_t handler) {
+ struct sigaction new, old;
+ int i;
+
+ new.sa_handler = handler;
+ new.sa_mask = 0; /* empty set */
+ new.sa_flags = SA_NODEFER | SA_RESETHAND;
+
+ i = sigaction(signum, &new, &old);
+ if (i < 0)
+ return SIG_ERR;
+ return old.sa_handler;
+}
public / ack.git / commitdiff