File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/m32r/kernel/ptrace.c b/arch/m32r/kernel/ptrace.c
new file mode 100644
index 0000000..51f5e9a
--- /dev/null
+++ b/arch/m32r/kernel/ptrace.c
@@ -0,0 +1,701 @@
+/*
+ * linux/arch/m32r/kernel/ptrace.c
+ *
+ * Copyright (C) 2002 Hirokazu Takata, Takeo Takahashi
+ * Copyright (C) 2004 Hirokazu Takata, Kei Sakamoto
+ *
+ * Original x86 implementation:
+ * By Ross Biro 1/23/92
+ * edited by Linus Torvalds
+ *
+ * Some code taken from sh version:
+ * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
+ * Some code taken from arm version:
+ * Copyright (C) 2000 Russell King
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/err.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/string.h>
+#include <linux/signal.h>
+
+#include <asm/cacheflush.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/mmu_context.h>
+
+/*
+ * This routine will get a word off of the process kernel stack.
+ */
+static inline unsigned long int
+get_stack_long(struct task_struct *task, int offset)
+{
+ unsigned long *stack;
+
+ stack = (unsigned long *)task_pt_regs(task);
+
+ return stack[offset];
+}
+
+/*
+ * This routine will put a word on the process kernel stack.
+ */
+static inline int
+put_stack_long(struct task_struct *task, int offset, unsigned long data)
+{
+ unsigned long *stack;
+
+ stack = (unsigned long *)task_pt_regs(task);
+ stack[offset] = data;
+
+ return 0;
+}
+
+static int reg_offset[] = {
+ PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5, PT_R6, PT_R7,
+ PT_R8, PT_R9, PT_R10, PT_R11, PT_R12, PT_FP, PT_LR, PT_SPU,
+};
+
+/*
+ * Read the word at offset "off" into the "struct user". 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 *data)
+{
+ unsigned long tmp;
+#ifndef NO_FPU
+ struct user * dummy = NULL;
+#endif
+
+ if ((off & 3) || off > sizeof(struct user) - 3)
+ return -EIO;
+
+ off >>= 2;
+ switch (off) {
+ case PT_EVB:
+ __asm__ __volatile__ (
+ "mvfc %0, cr5 \n\t"
+ : "=r" (tmp)
+ );
+ break;
+ case PT_CBR: {
+ unsigned long psw;
+ psw = get_stack_long(tsk, PT_PSW);
+ tmp = ((psw >> 8) & 1);
+ }
+ break;
+ case PT_PSW: {
+ unsigned long psw, bbpsw;
+ psw = get_stack_long(tsk, PT_PSW);
+ bbpsw = get_stack_long(tsk, PT_BBPSW);
+ tmp = ((psw >> 8) & 0xff) | ((bbpsw & 0xff) << 8);
+ }
+ break;
+ case PT_PC:
+ tmp = get_stack_long(tsk, PT_BPC);
+ break;
+ case PT_BPC:
+ off = PT_BBPC;
+ /* fall through */
+ default:
+ if (off < (sizeof(struct pt_regs) >> 2))
+ tmp = get_stack_long(tsk, off);
+#ifndef NO_FPU
+ else if (off >= (long)(&dummy->fpu >> 2) &&
+ off < (long)(&dummy->u_fpvalid >> 2)) {
+ if (!tsk_used_math(tsk)) {
+ if (off == (long)(&dummy->fpu.fpscr >> 2))
+ tmp = FPSCR_INIT;
+ else
+ tmp = 0;
+ } else
+ tmp = ((long *)(&tsk->thread.fpu >> 2))
+ [off - (long)&dummy->fpu];
+ } else if (off == (long)(&dummy->u_fpvalid >> 2))
+ tmp = !!tsk_used_math(tsk);
+#endif /* not NO_FPU */
+ else
+ tmp = 0;
+ }
+
+ return put_user(tmp, data);
+}
+
+static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
+ unsigned long data)
+{
+ int ret = -EIO;
+#ifndef NO_FPU
+ struct user * dummy = NULL;
+#endif
+
+ if ((off & 3) || off > sizeof(struct user) - 3)
+ return -EIO;
+
+ off >>= 2;
+ switch (off) {
+ case PT_EVB:
+ case PT_BPC:
+ case PT_SPI:
+ /* We don't allow to modify evb. */
+ ret = 0;
+ break;
+ case PT_PSW:
+ case PT_CBR: {
+ /* We allow to modify only cbr in psw */
+ unsigned long psw;
+ psw = get_stack_long(tsk, PT_PSW);
+ psw = (psw & ~0x100) | ((data & 1) << 8);
+ ret = put_stack_long(tsk, PT_PSW, psw);
+ }
+ break;
+ case PT_PC:
+ off = PT_BPC;
+ data &= ~1;
+ /* fall through */
+ default:
+ if (off < (sizeof(struct pt_regs) >> 2))
+ ret = put_stack_long(tsk, off, data);
+#ifndef NO_FPU
+ else if (off >= (long)(&dummy->fpu >> 2) &&
+ off < (long)(&dummy->u_fpvalid >> 2)) {
+ set_stopped_child_used_math(tsk);
+ ((long *)&tsk->thread.fpu)
+ [off - (long)&dummy->fpu] = data;
+ ret = 0;
+ } else if (off == (long)(&dummy->u_fpvalid >> 2)) {
+ conditional_stopped_child_used_math(data, tsk);
+ ret = 0;
+ }
+#endif /* not NO_FPU */
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ * Get all user integer registers.
+ */
+static int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
+{
+ struct pt_regs *regs = task_pt_regs(tsk);
+
+ return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
+}
+
+/*
+ * Set all user integer registers.
+ */
+static int ptrace_setregs(struct task_struct *tsk, void __user *uregs)
+{
+ struct pt_regs newregs;
+ int ret;
+
+ ret = -EFAULT;
+ if (copy_from_user(&newregs, uregs, sizeof(struct pt_regs)) == 0) {
+ struct pt_regs *regs = task_pt_regs(tsk);
+ *regs = newregs;
+ ret = 0;
+ }
+
+ return ret;
+}
+
+
+static inline int
+check_condition_bit(struct task_struct *child)
+{
+ return (int)((get_stack_long(child, PT_PSW) >> 8) & 1);
+}
+
+static int
+check_condition_src(unsigned long op, unsigned long regno1,
+ unsigned long regno2, struct task_struct *child)
+{
+ unsigned long reg1, reg2;
+
+ reg2 = get_stack_long(child, reg_offset[regno2]);
+
+ switch (op) {
+ case 0x0: /* BEQ */
+ reg1 = get_stack_long(child, reg_offset[regno1]);
+ return reg1 == reg2;
+ case 0x1: /* BNE */
+ reg1 = get_stack_long(child, reg_offset[regno1]);
+ return reg1 != reg2;
+ case 0x8: /* BEQZ */
+ return reg2 == 0;
+ case 0x9: /* BNEZ */
+ return reg2 != 0;
+ case 0xa: /* BLTZ */
+ return (int)reg2 < 0;
+ case 0xb: /* BGEZ */
+ return (int)reg2 >= 0;
+ case 0xc: /* BLEZ */
+ return (int)reg2 <= 0;
+ case 0xd: /* BGTZ */
+ return (int)reg2 > 0;
+ default:
+ /* never reached */
+ return 0;
+ }
+}
+
+static void
+compute_next_pc_for_16bit_insn(unsigned long insn, unsigned long pc,
+ unsigned long *next_pc,
+ struct task_struct *child)
+{
+ unsigned long op, op2, op3;
+ unsigned long disp;
+ unsigned long regno;
+ int parallel = 0;
+
+ if (insn & 0x00008000)
+ parallel = 1;
+ if (pc & 3)
+ insn &= 0x7fff; /* right slot */
+ else
+ insn >>= 16; /* left slot */
+
+ op = (insn >> 12) & 0xf;
+ op2 = (insn >> 8) & 0xf;
+ op3 = (insn >> 4) & 0xf;
+
+ if (op == 0x7) {
+ switch (op2) {
+ case 0xd: /* BNC */
+ case 0x9: /* BNCL */
+ if (!check_condition_bit(child)) {
+ disp = (long)(insn << 24) >> 22;
+ *next_pc = (pc & ~0x3) + disp;
+ return;
+ }
+ break;
+ case 0x8: /* BCL */
+ case 0xc: /* BC */
+ if (check_condition_bit(child)) {
+ disp = (long)(insn << 24) >> 22;
+ *next_pc = (pc & ~0x3) + disp;
+ return;
+ }
+ break;
+ case 0xe: /* BL */
+ case 0xf: /* BRA */
+ disp = (long)(insn << 24) >> 22;
+ *next_pc = (pc & ~0x3) + disp;
+ return;
+ break;
+ }
+ } else if (op == 0x1) {
+ switch (op2) {
+ case 0x0:
+ if (op3 == 0xf) { /* TRAP */
+#if 1
+ /* pass through */
+#else
+ /* kernel space is not allowed as next_pc */
+ unsigned long evb;
+ unsigned long trapno;
+ trapno = insn & 0xf;
+ __asm__ __volatile__ (
+ "mvfc %0, cr5\n"
+ :"=r"(evb)
+ :
+ );
+ *next_pc = evb + (trapno << 2);
+ return;
+#endif
+ } else if (op3 == 0xd) { /* RTE */
+ *next_pc = get_stack_long(child, PT_BPC);
+ return;
+ }
+ break;
+ case 0xc: /* JC */
+ if (op3 == 0xc && check_condition_bit(child)) {
+ regno = insn & 0xf;
+ *next_pc = get_stack_long(child,
+ reg_offset[regno]);
+ return;
+ }
+ break;
+ case 0xd: /* JNC */
+ if (op3 == 0xc && !check_condition_bit(child)) {
+ regno = insn & 0xf;
+ *next_pc = get_stack_long(child,
+ reg_offset[regno]);
+ return;
+ }
+ break;
+ case 0xe: /* JL */
+ case 0xf: /* JMP */
+ if (op3 == 0xc) { /* JMP */
+ regno = insn & 0xf;
+ *next_pc = get_stack_long(child,
+ reg_offset[regno]);
+ return;
+ }
+ break;
+ }
+ }
+ if (parallel)
+ *next_pc = pc + 4;
+ else
+ *next_pc = pc + 2;
+}
+
+static void
+compute_next_pc_for_32bit_insn(unsigned long insn, unsigned long pc,
+ unsigned long *next_pc,
+ struct task_struct *child)
+{
+ unsigned long op;
+ unsigned long op2;
+ unsigned long disp;
+ unsigned long regno1, regno2;
+
+ op = (insn >> 28) & 0xf;
+ if (op == 0xf) { /* branch 24-bit relative */
+ op2 = (insn >> 24) & 0xf;
+ switch (op2) {
+ case 0xd: /* BNC */
+ case 0x9: /* BNCL */
+ if (!check_condition_bit(child)) {
+ disp = (long)(insn << 8) >> 6;
+ *next_pc = (pc & ~0x3) + disp;
+ return;
+ }
+ break;
+ case 0x8: /* BCL */
+ case 0xc: /* BC */
+ if (check_condition_bit(child)) {
+ disp = (long)(insn << 8) >> 6;
+ *next_pc = (pc & ~0x3) + disp;
+ return;
+ }
+ break;
+ case 0xe: /* BL */
+ case 0xf: /* BRA */
+ disp = (long)(insn << 8) >> 6;
+ *next_pc = (pc & ~0x3) + disp;
+ return;
+ }
+ } else if (op == 0xb) { /* branch 16-bit relative */
+ op2 = (insn >> 20) & 0xf;
+ switch (op2) {
+ case 0x0: /* BEQ */
+ case 0x1: /* BNE */
+ case 0x8: /* BEQZ */
+ case 0x9: /* BNEZ */
+ case 0xa: /* BLTZ */
+ case 0xb: /* BGEZ */
+ case 0xc: /* BLEZ */
+ case 0xd: /* BGTZ */
+ regno1 = ((insn >> 24) & 0xf);
+ regno2 = ((insn >> 16) & 0xf);
+ if (check_condition_src(op2, regno1, regno2, child)) {
+ disp = (long)(insn << 16) >> 14;
+ *next_pc = (pc & ~0x3) + disp;
+ return;
+ }
+ break;
+ }
+ }
+ *next_pc = pc + 4;
+}
+
+static inline void
+compute_next_pc(unsigned long insn, unsigned long pc,
+ unsigned long *next_pc, struct task_struct *child)
+{
+ if (insn & 0x80000000)
+ compute_next_pc_for_32bit_insn(insn, pc, next_pc, child);
+ else
+ compute_next_pc_for_16bit_insn(insn, pc, next_pc, child);
+}
+
+static int
+register_debug_trap(struct task_struct *child, unsigned long next_pc,
+ unsigned long next_insn, unsigned long *code)
+{
+ struct debug_trap *p = &child->thread.debug_trap;
+ unsigned long addr = next_pc & ~3;
+
+ if (p->nr_trap == MAX_TRAPS) {
+ printk("kernel BUG at %s %d: p->nr_trap = %d\n",
+ __FILE__, __LINE__, p->nr_trap);
+ return -1;
+ }
+ p->addr[p->nr_trap] = addr;
+ p->insn[p->nr_trap] = next_insn;
+ p->nr_trap++;
+ if (next_pc & 3) {
+ *code = (next_insn & 0xffff0000) | 0x10f1;
+ /* xxx --> TRAP1 */
+ } else {
+ if ((next_insn & 0x80000000) || (next_insn & 0x8000)) {
+ *code = 0x10f17000;
+ /* TRAP1 --> NOP */
+ } else {
+ *code = (next_insn & 0xffff) | 0x10f10000;
+ /* TRAP1 --> xxx */
+ }
+ }
+ return 0;
+}
+
+static int
+unregister_debug_trap(struct task_struct *child, unsigned long addr,
+ unsigned long *code)
+{
+ struct debug_trap *p = &child->thread.debug_trap;
+ int i;
+
+ /* Search debug trap entry. */
+ for (i = 0; i < p->nr_trap; i++) {
+ if (p->addr[i] == addr)
+ break;
+ }
+ if (i >= p->nr_trap) {
+ /* The trap may be requested from debugger.
+ * ptrace should do nothing in this case.
+ */
+ return 0;
+ }
+
+ /* Recover original instruction code. */
+ *code = p->insn[i];
+
+ /* Shift debug trap entries. */
+ while (i < p->nr_trap - 1) {
+ p->insn[i] = p->insn[i + 1];
+ p->addr[i] = p->addr[i + 1];
+ i++;
+ }
+ p->nr_trap--;
+ return 1;
+}
+
+static void
+unregister_all_debug_traps(struct task_struct *child)
+{
+ struct debug_trap *p = &child->thread.debug_trap;
+ int i;
+
+ for (i = 0; i < p->nr_trap; i++)
+ access_process_vm(child, p->addr[i], &p->insn[i], sizeof(p->insn[i]), 1);
+ p->nr_trap = 0;
+}
+
+static inline void
+invalidate_cache(void)
+{
+#if defined(CONFIG_CHIP_M32700) || defined(CONFIG_CHIP_OPSP)
+
+ _flush_cache_copyback_all();
+
+#else /* ! CONFIG_CHIP_M32700 */
+
+ /* Invalidate cache */
+ __asm__ __volatile__ (
+ "ldi r0, #-1 \n\t"
+ "ldi r1, #0 \n\t"
+ "stb r1, @r0 ; cache off \n\t"
+ "; \n\t"
+ "ldi r0, #-2 \n\t"
+ "ldi r1, #1 \n\t"
+ "stb r1, @r0 ; cache invalidate \n\t"
+ ".fillinsn \n"
+ "0: \n\t"
+ "ldb r1, @r0 ; invalidate check \n\t"
+ "bnez r1, 0b \n\t"
+ "; \n\t"
+ "ldi r0, #-1 \n\t"
+ "ldi r1, #1 \n\t"
+ "stb r1, @r0 ; cache on \n\t"
+ : : : "r0", "r1", "memory"
+ );
+ /* FIXME: copying-back d-cache and invalidating i-cache are needed.
+ */
+#endif /* CONFIG_CHIP_M32700 */
+}
+
+/* Embed a debug trap (TRAP1) code */
+static int
+embed_debug_trap(struct task_struct *child, unsigned long next_pc)
+{
+ unsigned long next_insn, code;
+ unsigned long addr = next_pc & ~3;
+
+ if (access_process_vm(child, addr, &next_insn, sizeof(next_insn), 0)
+ != sizeof(next_insn)) {
+ return -1; /* error */
+ }
+
+ /* Set a trap code. */
+ if (register_debug_trap(child, next_pc, next_insn, &code)) {
+ return -1; /* error */
+ }
+ if (access_process_vm(child, addr, &code, sizeof(code), 1)
+ != sizeof(code)) {
+ return -1; /* error */
+ }
+ return 0; /* success */
+}
+
+void
+withdraw_debug_trap(struct pt_regs *regs)
+{
+ unsigned long addr;
+ unsigned long code;
+
+ addr = (regs->bpc - 2) & ~3;
+ regs->bpc -= 2;
+ if (unregister_debug_trap(current, addr, &code)) {
+ access_process_vm(current, addr, &code, sizeof(code), 1);
+ invalidate_cache();
+ }
+}
+
+void
+init_debug_traps(struct task_struct *child)
+{
+ struct debug_trap *p = &child->thread.debug_trap;
+ int i;
+ p->nr_trap = 0;
+ for (i = 0; i < MAX_TRAPS; i++) {
+ p->addr[i] = 0;
+ p->insn[i] = 0;
+ }
+}
+
+void user_enable_single_step(struct task_struct *child)
+{
+ unsigned long next_pc;
+ unsigned long pc, insn;
+
+ clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+
+ /* Compute next pc. */
+ pc = get_stack_long(child, PT_BPC);
+
+ if (access_process_vm(child, pc&~3, &insn, sizeof(insn), 0)
+ != sizeof(insn))
+ return;
+
+ compute_next_pc(insn, pc, &next_pc, child);
+ if (next_pc & 0x80000000)
+ return;
+
+ if (embed_debug_trap(child, next_pc))
+ return;
+
+ invalidate_cache();
+}
+
+void user_disable_single_step(struct task_struct *child)
+{
+ unregister_all_debug_traps(child);
+ invalidate_cache();
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure single step bits etc are not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+ /* nothing to do.. */
+}
+
+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) {
+ /*
+ * read word at location "addr" in the child process.
+ */
+ case PTRACE_PEEKTEXT:
+ case PTRACE_PEEKDATA:
+ ret = generic_ptrace_peekdata(child, addr, data);
+ break;
+
+ /*
+ * read the word at location addr in the USER area.
+ */
+ case PTRACE_PEEKUSR:
+ ret = ptrace_read_user(child, addr, datap);
+ break;
+
+ /*
+ * write the word at location addr.
+ */
+ case PTRACE_POKETEXT:
+ case PTRACE_POKEDATA:
+ ret = generic_ptrace_pokedata(child, addr, data);
+ if (ret == 0 && request == PTRACE_POKETEXT)
+ invalidate_cache();
+ break;
+
+ /*
+ * write the word at location addr in the USER area.
+ */
+ case PTRACE_POKEUSR:
+ ret = ptrace_write_user(child, addr, data);
+ break;
+
+ case PTRACE_GETREGS:
+ ret = ptrace_getregs(child, datap);
+ break;
+
+ case PTRACE_SETREGS:
+ ret = ptrace_setregs(child, datap);
+ break;
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+ return ret;
+}
+
+/* notification of system call entry/exit
+ * - triggered by current->work.syscall_trace
+ */
+void do_syscall_trace(void)
+{
+ if (!test_thread_flag(TIF_SYSCALL_TRACE))
+ return;
+ if (!(current->ptrace & PT_PTRACED))
+ return;
+ /* 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;
+ }
+}