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authorMike Frysinger <vapier@gentoo.org>2010-01-26 07:33:53 +0000
committerMike Frysinger <vapier@gentoo.org>2010-03-09 00:30:51 -0500
commite8f263dfd32a784a816fe68956e564f8ede4a9fc (patch)
tree58fcc786db192f13c3df7febee705adaaf61012c /arch/blackfin/include/asm/syscall.h
parente50e2f25c5b90abd00a1e5871c45094cf5207afc (diff)
downloadlinux-e8f263dfd32a784a816fe68956e564f8ede4a9fc.tar.gz
Blackfin: initial tracehook support
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'arch/blackfin/include/asm/syscall.h')
-rw-r--r--arch/blackfin/include/asm/syscall.h96
1 files changed, 96 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/syscall.h b/arch/blackfin/include/asm/syscall.h
new file mode 100644
index 00000000000..4921a4815cc
--- /dev/null
+++ b/arch/blackfin/include/asm/syscall.h
@@ -0,0 +1,96 @@
+/*
+ * Magic syscall break down functions
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __ASM_BLACKFIN_SYSCALL_H__
+#define __ASM_BLACKFIN_SYSCALL_H__
+
+/*
+ * Blackfin syscalls are simple:
+ * enter:
+ * p0: syscall number
+ * r{0,1,2,3,4,5}: syscall args 0,1,2,3,4,5
+ * exit:
+ * r0: return/error value
+ */
+
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <asm/ptrace.h>
+
+static inline long
+syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
+{
+ return regs->p0;
+}
+
+static inline void
+syscall_rollback(struct task_struct *task, struct pt_regs *regs)
+{
+ regs->p0 = regs->orig_p0;
+}
+
+static inline long
+syscall_get_error(struct task_struct *task, struct pt_regs *regs)
+{
+ return IS_ERR_VALUE(regs->r0) ? regs->r0 : 0;
+}
+
+static inline long
+syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
+{
+ return regs->r0;
+}
+
+static inline void
+syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
+ int error, long val)
+{
+ regs->r0 = error ? -error : val;
+}
+
+/**
+ * syscall_get_arguments()
+ * @task: unused
+ * @regs: the register layout to extract syscall arguments from
+ * @i: first syscall argument to extract
+ * @n: number of syscall arguments to extract
+ * @args: array to return the syscall arguments in
+ *
+ * args[0] gets i'th argument, args[n - 1] gets the i+n-1'th argument
+ */
+static inline void
+syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
+ unsigned int i, unsigned int n, unsigned long *args)
+{
+ /*
+ * Assume the ptrace layout doesn't change -- r5 is first in memory,
+ * then r4, ..., then r0. So we simply reverse the ptrace register
+ * array in memory to store into the args array.
+ */
+ long *aregs = &regs->r0 - i;
+
+ BUG_ON(i > 5 || i + n > 6);
+
+ while (n--)
+ *args++ = *aregs--;
+}
+
+/* See syscall_get_arguments() comments */
+static inline void
+syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
+ unsigned int i, unsigned int n, const unsigned long *args)
+{
+ long *aregs = &regs->r0 - i;
+
+ BUG_ON(i > 5 || i + n > 6);
+
+ while (n--)
+ *aregs-- = *args++;
+}
+
+#endif