unicore32 additional architecture files: ptrace handling
This patch adds ptrace support.
Changed from previous version:
1. disable arch_has_single_step and remove single-step instruction handler
2. add 'Ross Biro 1/23/92' contributor information
3. clean unused codes
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/unicore32/include/asm/ptrace.h b/arch/unicore32/include/asm/ptrace.h
new file mode 100644
index 0000000..b9caf9b
--- /dev/null
+++ b/arch/unicore32/include/asm/ptrace.h
@@ -0,0 +1,133 @@
+/*
+ * linux/arch/unicore32/include/asm/ptrace.h
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __UNICORE_PTRACE_H__
+#define __UNICORE_PTRACE_H__
+
+#define PTRACE_GET_THREAD_AREA 22
+
+/*
+ * PSR bits
+ */
+#define USER_MODE 0x00000010
+#define REAL_MODE 0x00000011
+#define INTR_MODE 0x00000012
+#define PRIV_MODE 0x00000013
+#define ABRT_MODE 0x00000017
+#define EXTN_MODE 0x0000001b
+#define SUSR_MODE 0x0000001f
+#define MODE_MASK 0x0000001f
+#define PSR_R_BIT 0x00000040
+#define PSR_I_BIT 0x00000080
+#define PSR_V_BIT 0x10000000
+#define PSR_C_BIT 0x20000000
+#define PSR_Z_BIT 0x40000000
+#define PSR_S_BIT 0x80000000
+
+/*
+ * Groups of PSR bits
+ */
+#define PSR_f 0xff000000 /* Flags */
+#define PSR_c 0x000000ff /* Control */
+
+#ifndef __ASSEMBLY__
+
+/*
+ * This struct defines the way the registers are stored on the
+ * stack during a system call. Note that sizeof(struct pt_regs)
+ * has to be a multiple of 8.
+ */
+struct pt_regs {
+ unsigned long uregs[34];
+};
+
+#define UCreg_asr uregs[32]
+#define UCreg_pc uregs[31]
+#define UCreg_lr uregs[30]
+#define UCreg_sp uregs[29]
+#define UCreg_ip uregs[28]
+#define UCreg_fp uregs[27]
+#define UCreg_26 uregs[26]
+#define UCreg_25 uregs[25]
+#define UCreg_24 uregs[24]
+#define UCreg_23 uregs[23]
+#define UCreg_22 uregs[22]
+#define UCreg_21 uregs[21]
+#define UCreg_20 uregs[20]
+#define UCreg_19 uregs[19]
+#define UCreg_18 uregs[18]
+#define UCreg_17 uregs[17]
+#define UCreg_16 uregs[16]
+#define UCreg_15 uregs[15]
+#define UCreg_14 uregs[14]
+#define UCreg_13 uregs[13]
+#define UCreg_12 uregs[12]
+#define UCreg_11 uregs[11]
+#define UCreg_10 uregs[10]
+#define UCreg_09 uregs[9]
+#define UCreg_08 uregs[8]
+#define UCreg_07 uregs[7]
+#define UCreg_06 uregs[6]
+#define UCreg_05 uregs[5]
+#define UCreg_04 uregs[4]
+#define UCreg_03 uregs[3]
+#define UCreg_02 uregs[2]
+#define UCreg_01 uregs[1]
+#define UCreg_00 uregs[0]
+#define UCreg_ORIG_00 uregs[33]
+
+#ifdef __KERNEL__
+
+#define user_mode(regs) \
+ (processor_mode(regs) == USER_MODE)
+
+#define processor_mode(regs) \
+ ((regs)->UCreg_asr & MODE_MASK)
+
+#define interrupts_enabled(regs) \
+ (!((regs)->UCreg_asr & PSR_I_BIT))
+
+#define fast_interrupts_enabled(regs) \
+ (!((regs)->UCreg_asr & PSR_R_BIT))
+
+/* Are the current registers suitable for user mode?
+ * (used to maintain security in signal handlers)
+ */
+static inline int valid_user_regs(struct pt_regs *regs)
+{
+ unsigned long mode = regs->UCreg_asr & MODE_MASK;
+
+ /*
+ * Always clear the R (REAL) bits
+ */
+ regs->UCreg_asr &= ~(PSR_R_BIT);
+
+ if ((regs->UCreg_asr & PSR_I_BIT) == 0) {
+ if (mode == USER_MODE)
+ return 1;
+ }
+
+ /*
+ * Force ASR to something logical...
+ */
+ regs->UCreg_asr &= PSR_f | USER_MODE;
+
+ return 0;
+}
+
+#define instruction_pointer(regs) ((regs)->UCreg_pc)
+
+#endif /* __KERNEL__ */
+
+#endif /* __ASSEMBLY__ */
+
+#endif
+
diff --git a/arch/unicore32/kernel/ptrace.c b/arch/unicore32/kernel/ptrace.c
new file mode 100644
index 0000000..9f07c08
--- /dev/null
+++ b/arch/unicore32/kernel/ptrace.c
@@ -0,0 +1,149 @@
+/*
+ * linux/arch/unicore32/kernel/ptrace.c
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * By Ross Biro 1/23/92
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/signal.h>
+#include <linux/uaccess.h>
+
+/*
+ * this routine will get a word off of the processes privileged stack.
+ * the offset is how far from the base addr as stored in the THREAD.
+ * this routine assumes that all the privileged stacks are in our
+ * data space.
+ */
+static inline long get_user_reg(struct task_struct *task, int offset)
+{
+ return task_pt_regs(task)->uregs[offset];
+}
+
+/*
+ * this routine will put a word on the processes privileged stack.
+ * the offset is how far from the base addr as stored in the THREAD.
+ * this routine assumes that all the privileged stacks are in our
+ * data space.
+ */
+static inline int
+put_user_reg(struct task_struct *task, int offset, long data)
+{
+ struct pt_regs newregs, *regs = task_pt_regs(task);
+ int ret = -EINVAL;
+
+ newregs = *regs;
+ newregs.uregs[offset] = data;
+
+ if (valid_user_regs(&newregs)) {
+ regs->uregs[offset] = data;
+ ret = 0;
+ }
+
+ return ret;
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ */
+void ptrace_disable(struct task_struct *child)
+{
+}
+
+/*
+ * We actually access the pt_regs stored on the kernel stack.
+ */
+static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
+ unsigned long __user *ret)
+{
+ unsigned long tmp;
+
+ tmp = 0;
+ if (off < sizeof(struct pt_regs))
+ tmp = get_user_reg(tsk, off >> 2);
+
+ return put_user(tmp, ret);
+}
+
+/*
+ * We actually access the pt_regs stored on the kernel stack.
+ */
+static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
+ unsigned long val)
+{
+ if (off >= sizeof(struct pt_regs))
+ return 0;
+
+ return put_user_reg(tsk, off >> 2, val);
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+ unsigned long addr, unsigned long data)
+{
+ int ret;
+ unsigned long __user *datap = (unsigned long __user *) data;
+
+ switch (request) {
+ case PTRACE_PEEKUSR:
+ ret = ptrace_read_user(child, addr, datap);
+ break;
+
+ case PTRACE_POKEUSR:
+ ret = ptrace_write_user(child, addr, data);
+ break;
+
+ case PTRACE_GET_THREAD_AREA:
+ ret = put_user(task_pt_regs(child)->UCreg_16,
+ datap);
+ break;
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+ return ret;
+}
+
+asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
+{
+ unsigned long ip;
+
+ if (!test_thread_flag(TIF_SYSCALL_TRACE))
+ return scno;
+ if (!(current->ptrace & PT_PTRACED))
+ return scno;
+
+ /*
+ * Save IP. IP is used to denote syscall entry/exit:
+ * IP = 0 -> entry, = 1 -> exit
+ */
+ ip = regs->UCreg_ip;
+ regs->UCreg_ip = why;
+
+ current_thread_info()->syscall = scno;
+
+ /* the 0x80 provides a way for the tracing parent to distinguish
+ between a syscall stop and SIGTRAP delivery */
+ ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
+ ? 0x80 : 0));
+ /*
+ * this isn't the same as continuing with a signal, but it will do
+ * for normal use. strace only continues with a signal if the
+ * stopping signal is not SIGTRAP. -brl
+ */
+ if (current->exit_code) {
+ send_sig(current->exit_code, current, 1);
+ current->exit_code = 0;
+ }
+ regs->UCreg_ip = ip;
+
+ return current_thread_info()->syscall;
+}