add capability subsystem and syscalls

5 files changed, 123 insertions, 5 deletions

diff --git a/include/apos/caps.h b/include/apos/caps.h
new file mode 100644
index 0000000..e8ef76b
--- /dev/null
+++ b/include/apos/caps.h
@@ -0,0 +1,70 @@
+#ifndef APOS_CAPS_H
+#define APOS_CAPS_H
+
+/**
+ * @file caps.h
+ * Capabilities of threads.
+ * \todo The list of capabilities should maybe be placed in some other file so
+ * as to easier extract it into userspace programs.
+ */
+
+#include <apos/bits.h>
+
+/** Helper typedef for capabilities. */
+typedef unsigned char capflags_t;
+
+enum {
+	/** Thread is allowed to set capabilities of other threads. */
+	CAP_CAPS = (1 << 0),
+
+	/** Thread is allowed to modify process statuses, exec/fork/etc. */
+	CAP_PROC = (1 << 1),
+
+	/** Thread is allowed to force interrupt to callback in other thread. */
+	CAP_CALL = (1 << 2),
+};
+
+/**
+ * Check that offset is OK.
+ *
+ * @param o Offset to check.
+ * @return \ref true is OK, \ref false otherwise.
+ */
+#define cap_off_ok(o) (o == 0)
+
+/**
+ * Set capabilities.
+ *
+ * @param x Capabilities to modify.
+ * @param o Offset.
+ * @param c Capabilities to set.
+ */
+#define set_caps(x, o, c) set_bits(x, c)
+
+/**
+ * Clear capabilities.
+ *
+ * @param x Capabilities to modify.
+ * @param o Offset.
+ * @param c Capabilities to set.
+ */
+#define clear_caps(x, o, c) clear_bits(x, c)
+
+/**
+ * Copy capabilities.
+ *
+ * @param x Capabilities to copy to.
+ * @param y Capabilities to copy from.
+ */
+#define copy_caps(x, y) (x = y)
+
+/**
+ * Get capabilities at offset \p o.
+ *
+ * @param x Capabilities to get from.
+ * @param o Offset to get capabilities from.
+ * @return Capabilities at offset \p o.
+ */
+#define get_caps(x, o) (x)
+
+#endif /* APOS_CAPS_H */
diff --git a/include/apos/syscalls.h b/include/apos/syscalls.h
index 229e17e..0a6f0c7 100644
--- a/include/apos/syscalls.h
+++ b/include/apos/syscalls.h
@@ -108,6 +108,15 @@ enum {
 	/** Get system parameters. */
 	SYS_CONF_GET,
 
+	/** Set capability of thread. */
+	SYS_SET_CAP,
+
+	/** Get capabilities of thread. */
+	SYS_GET_CAP,
+
+	/** Clear capability of thread. */
+	SYS_CLEAR_CAP,
+
 	/** Shutdown, reboot, etc. */
 	SYS_POWEROFF,
 	/** @} */
diff --git a/include/apos/tcb.h b/include/apos/tcb.h
index 9e63a9a..41b5237 100644
--- a/include/apos/tcb.h
+++ b/include/apos/tcb.h
@@ -10,6 +10,7 @@
  */
 
 #include <apos/mem_regions.h>
+#include <apos/caps.h>
 #include <apos/types.h>
 #include <arch/tcb.h> /* arch-specific data */
 
@@ -108,8 +109,8 @@ struct tcb {
 	/** Address of callback function in servers. */
 	vm_t callback;
 
-	/** Address of signal callback. */
-	vm_t signal;
+	/** Capabilities of thread. */
+	capflags_t caps;
 
 	/** Address of this thread's stack base. */
 	vm_t thread_stack;
diff --git a/include/apos/types.h b/include/apos/types.h
index f249705..e06ccd0 100644
--- a/include/apos/types.h
+++ b/include/apos/types.h
@@ -455,6 +455,8 @@ typedef uint_fast16_t vmflags_t;
  */
 /* should this enum be somewhere else? */
 enum status_codes {
+	/** Permission error. */
+	ERR_PERM = -10,
 	/** Internal error, should probably halt */
 	ERR_INT = -9,
 	/** Something went wrong :/ */
diff --git a/include/apos/uapi.h b/include/apos/uapi.h
index 5d61966..d0ce350 100644
--- a/include/apos/uapi.h
+++ b/include/apos/uapi.h
@@ -525,14 +525,14 @@ SYSCALL_DECLARE2(exec, bin, interp);
 /**
  * Kill syscall.
  *
- * @param a Unused.
+ * @param tid Thread ID to kill. 0 if self.
  * @param b Unused.
  * @param c Unused.
  * @param d Unused.
  * @param e Unused.
  * @return No.
  */
-SYSCALL_DECLARE0(kill);
+SYSCALL_DECLARE1(kill, tid);
 
 /**
  * Signal process syscall.
@@ -587,11 +587,47 @@ SYSCALL_DECLARE2(conf_set, param, val);
  * @param c Unused.
  * @param d Unused.
  * @param e Unused.
- * @return \ref OK and 0.
+ * @return \ref OK.
  */
 SYSCALL_DECLARE1(conf_get, param);
 
 /**
+ * Set capabilities.
+ *
+ * @param tid Thread ID whose capabilities to set.
+ * @param off Offset of capability, multiple of \c bits(cap).
+ * @param caps Mask of capabilities to set.
+ * @param d Unused.
+ * @param e Unused.
+ * @return \ref OK on success, \ref ERR_INVAL on invalid input.
+ */
+SYSCALL_DECLARE3(set_cap, tid, off, caps);
+
+/**
+ * Get capabilities.
+ *
+ * @param tid Thread ID whose capabilities to get.
+ * @param off Offset of capability, multiple of \c bits(cap).
+ * @param c Unused.
+ * @param d Unused.
+ * @param e Unused.
+ * @return \ref OK, capabilities.
+ */
+SYSCALL_DECLARE2(get_cap, tid, off);
+
+/**
+ * Clear capabilities.
+ *
+ * @param tid Thread ID whose capabilities to clear.
+ * @param off Offset of capability, multiple of \c bits(cap).
+ * @param cap Mask of capabilities to clear.
+ * @param d Unused.
+ * @param e Unused.
+ * @return \ref OK.
+ */
+SYSCALL_DECLARE3(clear_cap, tid, off, cap);
+
+/**
  * Power off syscall.
  *
  * Either shut down or reboot system.