[PATCH 17/24] C6X: ptrace support

Mark Salter
2011-08-22T20:11:10Z

Signed-off-by: Mark Salter <msalter@redhat.com>
---
arch/c6x/include/asm/ptrace.h | 181 +++++++++++++++++++++++++++++++++++
arch/c6x/kernel/ptrace.c | 207 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 388 insertions(+), 0 deletions(-)
create mode 100644 arch/c6x/include/asm/ptrace.h
create mode 100644 arch/c6x/kernel/ptrace.c

diff --git a/arch/c6x/include/asm/ptrace.h b/arch/c6x/include/asm/ptrace.h
new file mode 100644
index 0000000..347f2ed
--- /dev/null
+++ b/arch/c6x/include/asm/ptrace.h
@@ -0,0 +1,181 @@
+/*
+ * Copyright (C) 2004, 2006, 2009, 2010 Texas Instruments Incorporated
+ * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
+ *
+ * Updated for 2.6.34: Mark Salter <msalter@redhat.com>
+ *
+ * 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 _ASM_C6X_PTRACE_H
+#define _ASM_C6X_PTRACE_H
+
+#if defined(__TMS320C6XPLUS__) || defined(_TMS320C6400_PLUS)
+#define BKPT_OPCODE 0x56454314 /* illegal opcode */
+#else
+#define BKPT_OPCODE 0x0000a122 /* BNOP .S2 0,5 */
+#endif
+
+#ifdef _BIG_ENDIAN
+#define PT_LO(odd, even) odd
+#define PT_HI(odd, even) even
+#else
+#define PT_LO(odd, even) even
+#define PT_HI(odd, even) odd
+#endif
+
+#define PT_A4_ORG PT_LO(1, 0)
+#define PT_TSR PT_HI(1, 0)
+#define PT_ILC PT_LO(3, 2)
+#define PT_RILC PT_HI(3, 2)
+#define PT_CSR PT_LO(5, 4)
+#define PT_PC PT_HI(5, 4)
+#define PT_B16 PT_LO(7, 6)
+#define PT_B17 PT_HI(7, 6)
+#define PT_B18 PT_LO(9, 8)
+#define PT_B19 PT_HI(9, 8)
+#define PT_B20 PT_LO(11, 10)
+#define PT_B21 PT_HI(11, 10)
+#define PT_B22 PT_LO(13, 12)
+#define PT_B23 PT_HI(13, 12)
+#define PT_B24 PT_LO(15, 14)
+#define PT_B25 PT_HI(15, 14)
+#define PT_B26 PT_LO(17, 16)
+#define PT_B27 PT_HI(17, 16)
+#define PT_B28 PT_LO(19, 18)
+#define PT_B29 PT_HI(19, 18)
+#define PT_B30 PT_LO(21, 20)
+#define PT_B31 PT_HI(21, 20)
+#define PT_B0 PT_LO(23, 22)
+#define PT_B1 PT_HI(23, 22)
+#define PT_B2 PT_LO(25, 24)
+#define PT_B3 PT_HI(25, 24)
+#define PT_B4 PT_LO(27, 26)
+#define PT_B5 PT_HI(27, 26)
+#define PT_B6 PT_LO(29, 28)
+#define PT_B7 PT_HI(29, 28)
+#define PT_B8 PT_LO(31, 30)
+#define PT_B9 PT_HI(31, 30)
+#define PT_B10 PT_LO(33, 32)
+#define PT_B11 PT_HI(33, 32)
+#define PT_B12 PT_LO(35, 34)
+#define PT_B13 PT_HI(35, 34)
+#define PT_A16 PT_LO(37, 36)
+#define PT_A17 PT_HI(37, 36)
+#define PT_A18 PT_LO(39, 38)
+#define PT_A19 PT_HI(39, 38)
+#define PT_A20 PT_LO(41, 40)
+#define PT_A21 PT_HI(41, 40)
+#define PT_A22 PT_LO(43, 42)
+#define PT_A23 PT_HI(43, 42)
+#define PT_A24 PT_LO(45, 44)
+#define PT_A25 PT_HI(45, 44)
+#define PT_A26 PT_LO(47, 46)
+#define PT_A27 PT_HI(47, 46)
+#define PT_A28 PT_LO(49, 48)
+#define PT_A29 PT_HI(49, 48)
+#define PT_A30 PT_LO(51, 50)
+#define PT_A31 PT_HI(51, 50)
+#define PT_A0 PT_LO(53, 52)
+#define PT_A1 PT_HI(53, 52)
+#define PT_A2 PT_LO(55, 54)
+#define PT_A3 PT_HI(55, 54)
+#define PT_A4 PT_LO(57, 56)
+#define PT_A5 PT_HI(57, 56)
+#define PT_A6 PT_LO(59, 58)
+#define PT_A7 PT_HI(59, 58)
+#define PT_A8 PT_LO(61, 60)
+#define PT_A9 PT_HI(61, 60)
+#define PT_A10 PT_LO(63, 62)
+#define PT_A11 PT_HI(63, 62)
+#define PT_A12 PT_LO(65, 64)
+#define PT_A13 PT_HI(65, 64)
+#define PT_A14 PT_LO(67, 66)
+#define PT_A15 PT_HI(67, 66)
+#define PT_B14 PT_LO(69, 68)
+#define PT_B15 PT_HI(69, 68)
+
+#define NR_PTREGS 70
+
+#define PT_DP PT_B14 /* Data Segment Pointer (B14) */
+#define PT_SP PT_B15 /* Stack Pointer (B15) */
+
+#ifndef __ASSEMBLY__
+
+#ifdef _BIG_ENDIAN
+#define REG_PAIR(odd, even) unsigned long odd; unsigned long even
+#else
+#define REG_PAIR(odd, even) unsigned long even; unsigned long odd
+#endif
+
+/*
+ * this struct defines the way the registers are stored on the
+ * stack during a system call. fields defined with REG_PAIR
+ * are saved and restored using double-word memory operations
+ * which means the word ordering of the pair depends on endianess.
+ */
+struct pt_regs {
+ REG_PAIR(tsr, orig_a4);
+ REG_PAIR(rilc, ilc);
+ REG_PAIR(pc, csr);
+
+ REG_PAIR(b17, b16);
+ REG_PAIR(b19, b18);
+ REG_PAIR(b21, b20);
+ REG_PAIR(b23, b22);
+ REG_PAIR(b25, b24);
+ REG_PAIR(b27, b26);
+ REG_PAIR(b29, b28);
+ REG_PAIR(b31, b30);
+
+ REG_PAIR(b1, b0);
+ REG_PAIR(b3, b2);
+ REG_PAIR(b5, b4);
+ REG_PAIR(b7, b6);
+ REG_PAIR(b9, b8);
+ REG_PAIR(b11, b10);
+ REG_PAIR(b13, b12);
+
+ REG_PAIR(a17, a16);
+ REG_PAIR(a19, a18);
+ REG_PAIR(a21, a20);
+ REG_PAIR(a23, a22);
+ REG_PAIR(a25, a24);
+ REG_PAIR(a27, a26);
+ REG_PAIR(a29, a28);
+ REG_PAIR(a31, a30);
+
+ REG_PAIR(a1, a0);
+ REG_PAIR(a3, a2);
+ REG_PAIR(a5, a4);
+ REG_PAIR(a7, a6);
+ REG_PAIR(a9, a8);
+ REG_PAIR(a11, a10);
+ REG_PAIR(a13, a12);
+
+ REG_PAIR(a15, a14);
+ REG_PAIR(sp, dp);
+};
+
+#define PTRACE_GETREGS 12
+#define PTRACE_SETREGS 13
+#define PTRACE_GETFPREGS 14
+#define PTRACE_SETFPREGS 15
+
+#ifdef __KERNEL__
+
+#include <linux/linkage.h>
+
+#define user_mode(regs) ((((regs)->tsr) & 0x40) != 0)
+
+#define instruction_pointer(regs) ((regs)->pc)
+#define profile_pc(regs) instruction_pointer(regs)
+extern void show_regs(struct pt_regs *);
+
+extern asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs);
+extern asmlinkage void syscall_trace_exit(struct pt_regs *regs);
+
+#endif /* __KERNEL__ */
+#endif /* __ASSEMBLY__ */
+#endif /* _ASM_C6X_PTRACE_H */
diff --git a/arch/c6x/kernel/ptrace.c b/arch/c6x/kernel/ptrace.c
new file mode 100644
index 0000000..96fd4a5
--- /dev/null
+++ b/arch/c6x/kernel/ptrace.c
@@ -0,0 +1,207 @@
+/*
+ * Port on Texas Instruments TMS320C6x architecture
+ *
+ * Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
+ * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
+ *
+ * Updated for 2.6.34: Mark Salter <msalter@redhat.com>
+ *
+ * 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/ptrace.h>
+#include <linux/tracehook.h>
+#include <linux/regset.h>
+#include <linux/elf.h>
+
+#include <asm/cacheflush.h>
+
+#define PT_REG_SIZE (sizeof(struct pt_regs))
+
+/*
+ * Called by kernel/ptrace.c when detaching.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+ /* nothing to do */
+}
+
+/*
+ * Get a register number from live pt_regs for the specified task.
+ */
+static inline long get_reg(struct task_struct *task, int regno)
+{
+ long *addr = (long *)task_pt_regs(task);
+
+ if (regno == PT_TSR || regno == PT_CSR)
+ return 0;
+
+ return addr[regno];
+}
+
+/*
+ * Write contents of register REGNO in task TASK.
+ */
+static inline int put_reg(struct task_struct *task,
+ int regno,
+ unsigned long data)
+{
+ unsigned long *addr = (unsigned long *)task_pt_regs(task);
+
+ if (regno != PT_TSR && regno != PT_CSR)
+ addr[regno] = data;
+
+ return 0;
+}
+
+/* regset get/set implementations */
+
+static int gpr_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ struct pt_regs *regs = task_pt_regs(target);
+
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+ regs,
+ 0, sizeof(*regs));
+}
+
+static int gpr_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ int ret;
+ struct pt_regs *regs = task_pt_regs(target);
+
+ /* Don't copyin TSR or CSR */
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &regs,
+ 0, PT_TSR * sizeof(long));
+ if (ret)
+ return ret;
+
+ ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+ PT_TSR * sizeof(long),
+ (PT_TSR + 1) * sizeof(long));
+ if (ret)
+ return ret;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &regs,
+ (PT_TSR + 1) * sizeof(long),
+ PT_CSR * sizeof(long));
+ if (ret)
+ return ret;
+
+ ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+ PT_CSR * sizeof(long),
+ (PT_CSR + 1) * sizeof(long));
+ if (ret)
+ return ret;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ &regs,
+ (PT_CSR + 1) * sizeof(long), -1);
+ return ret;
+}
+
+enum c6x_regset {
+ REGSET_GPR,
+};
+
+static const struct user_regset c6x_regsets[] = {
+ [REGSET_GPR] = {
+ .core_note_type = NT_PRSTATUS,
+ .n = ELF_NGREG,
+ .size = sizeof(u32),
+ .align = sizeof(u32),
+ .get = gpr_get,
+ .set = gpr_set
+ },
+};
+
+static const struct user_regset_view user_c6x_native_view = {
+ .name = "tic6x",
+ .e_machine = EM_TI_C6000,
+ .regsets = c6x_regsets,
+ .n = ARRAY_SIZE(c6x_regsets),
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+ return &user_c6x_native_view;
+}
+
+/*
+ * Perform ptrace request
+ */
+long arch_ptrace(struct task_struct *child, long request,
+ unsigned long addr, unsigned long data)
+{
+ unsigned long __user *datap = (unsigned long __user *) data;
+ int ret = 0;
+
+ switch (request) {
+ /*
+ * write the word at location addr.
+ */
+ case PTRACE_POKETEXT:
+ ret = generic_ptrace_pokedata(child, addr, data);
+ if (ret == 0 && request == PTRACE_POKETEXT)
+ flush_icache_range(addr, addr + 4);
+ break;
+
+ /*
+ * get all gp regs from the child.
+ */
+ case PTRACE_GETREGS:
+ return copy_regset_to_user(child, &user_c6x_native_view,
+ REGSET_GPR,
+ 0, NR_PTREGS * sizeof(long),
+ datap);
+
+ /*
+ * set all gp regs in the child.
+ */
+ case PTRACE_SETREGS:
+ return copy_regset_from_user(child, &user_c6x_native_view,
+ REGSET_GPR,
+ 0, NR_PTREGS * sizeof(long),
+ datap);
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ * handle tracing of system call entry
+ * - return the revised system call number or ULONG_MAX to cause ENOSYS
+ */
+asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs)
+{
+ if (tracehook_report_syscall_entry(regs))
+ /* tracing decided this syscall should not happen, so
+ * We'll return a bogus call number to get an ENOSYS
+ * error, but leave the original number in
+ * regs->orig_a4
+ */
+ return ULONG_MAX;
+
+ return regs->b0;
+}
+
+/*
+ * handle tracing of system call exit
+ */
+asmlinkage void syscall_trace_exit(struct pt_regs *regs)
+{
+ tracehook_report_syscall_exit(regs, 0);
+}
--
1.7.6