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Diffstat (limited to 'arch/arm/kernel/ptrace.c')
-rw-r--r--arch/arm/kernel/ptrace.c478
1 files changed, 401 insertions, 77 deletions
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 89882a1d0187..19c6816db61e 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -19,6 +19,8 @@
#include <linux/init.h>
#include <linux/signal.h>
#include <linux/uaccess.h>
+#include <linux/perf_event.h>
+#include <linux/hw_breakpoint.h>
#include <asm/pgtable.h>
#include <asm/system.h>
@@ -52,6 +54,102 @@
#define BREAKINST_THUMB 0xde01
#endif
+struct pt_regs_offset {
+ const char *name;
+ int offset;
+};
+
+#define REG_OFFSET_NAME(r) \
+ {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
+#define REG_OFFSET_END {.name = NULL, .offset = 0}
+
+static const struct pt_regs_offset regoffset_table[] = {
+ REG_OFFSET_NAME(r0),
+ REG_OFFSET_NAME(r1),
+ REG_OFFSET_NAME(r2),
+ REG_OFFSET_NAME(r3),
+ REG_OFFSET_NAME(r4),
+ REG_OFFSET_NAME(r5),
+ REG_OFFSET_NAME(r6),
+ REG_OFFSET_NAME(r7),
+ REG_OFFSET_NAME(r8),
+ REG_OFFSET_NAME(r9),
+ REG_OFFSET_NAME(r10),
+ REG_OFFSET_NAME(fp),
+ REG_OFFSET_NAME(ip),
+ REG_OFFSET_NAME(sp),
+ REG_OFFSET_NAME(lr),
+ REG_OFFSET_NAME(pc),
+ REG_OFFSET_NAME(cpsr),
+ REG_OFFSET_NAME(ORIG_r0),
+ REG_OFFSET_END,
+};
+
+/**
+ * regs_query_register_offset() - query register offset from its name
+ * @name: the name of a register
+ *
+ * regs_query_register_offset() returns the offset of a register in struct
+ * pt_regs from its name. If the name is invalid, this returns -EINVAL;
+ */
+int regs_query_register_offset(const char *name)
+{
+ const struct pt_regs_offset *roff;
+ for (roff = regoffset_table; roff->name != NULL; roff++)
+ if (!strcmp(roff->name, name))
+ return roff->offset;
+ return -EINVAL;
+}
+
+/**
+ * regs_query_register_name() - query register name from its offset
+ * @offset: the offset of a register in struct pt_regs.
+ *
+ * regs_query_register_name() returns the name of a register from its
+ * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
+ */
+const char *regs_query_register_name(unsigned int offset)
+{
+ const struct pt_regs_offset *roff;
+ for (roff = regoffset_table; roff->name != NULL; roff++)
+ if (roff->offset == offset)
+ return roff->name;
+ return NULL;
+}
+
+/**
+ * regs_within_kernel_stack() - check the address in the stack
+ * @regs: pt_regs which contains kernel stack pointer.
+ * @addr: address which is checked.
+ *
+ * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
+ * If @addr is within the kernel stack, it returns true. If not, returns false.
+ */
+bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
+{
+ return ((addr & ~(THREAD_SIZE - 1)) ==
+ (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
+}
+
+/**
+ * regs_get_kernel_stack_nth() - get Nth entry of the stack
+ * @regs: pt_regs which contains kernel stack pointer.
+ * @n: stack entry number.
+ *
+ * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
+ * is specified by @regs. If the @n th entry is NOT in the kernel stack,
+ * this returns 0.
+ */
+unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
+{
+ unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
+ addr += n;
+ if (regs_within_kernel_stack(regs, (unsigned long)addr))
+ return *addr;
+ else
+ return 0;
+}
+
/*
* 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.
@@ -452,12 +550,23 @@ void ptrace_cancel_bpt(struct task_struct *child)
clear_breakpoint(child, &child->thread.debug.bp[i]);
}
+void user_disable_single_step(struct task_struct *task)
+{
+ task->ptrace &= ~PT_SINGLESTEP;
+ ptrace_cancel_bpt(task);
+}
+
+void user_enable_single_step(struct task_struct *task)
+{
+ task->ptrace |= PT_SINGLESTEP;
+}
+
/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
{
- single_step_disable(child);
+ user_disable_single_step(child);
}
/*
@@ -499,10 +608,41 @@ static struct undef_hook thumb_break_hook = {
.fn = break_trap,
};
+static int thumb2_break_trap(struct pt_regs *regs, unsigned int instr)
+{
+ unsigned int instr2;
+ void __user *pc;
+
+ /* Check the second half of the instruction. */
+ pc = (void __user *)(instruction_pointer(regs) + 2);
+
+ if (processor_mode(regs) == SVC_MODE) {
+ instr2 = *(u16 *) pc;
+ } else {
+ get_user(instr2, (u16 __user *)pc);
+ }
+
+ if (instr2 == 0xa000) {
+ ptrace_break(current, regs);
+ return 0;
+ } else {
+ return 1;
+ }
+}
+
+static struct undef_hook thumb2_break_hook = {
+ .instr_mask = 0xffff,
+ .instr_val = 0xf7f0,
+ .cpsr_mask = PSR_T_BIT,
+ .cpsr_val = PSR_T_BIT,
+ .fn = thumb2_break_trap,
+};
+
static int __init ptrace_break_init(void)
{
register_undef_hook(&arm_break_hook);
register_undef_hook(&thumb_break_hook);
+ register_undef_hook(&thumb2_break_hook);
return 0;
}
@@ -521,7 +661,13 @@ static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
return -EIO;
tmp = 0;
- if (off < sizeof(struct pt_regs))
+ if (off == PT_TEXT_ADDR)
+ tmp = tsk->mm->start_code;
+ else if (off == PT_DATA_ADDR)
+ tmp = tsk->mm->start_data;
+ else if (off == PT_TEXT_END_ADDR)
+ tmp = tsk->mm->end_code;
+ else if (off < sizeof(struct pt_regs))
tmp = get_user_reg(tsk, off >> 2);
return put_user(tmp, ret);
@@ -663,7 +809,7 @@ static int ptrace_getvfpregs(struct task_struct *tsk, void __user *data)
union vfp_state *vfp = &thread->vfpstate;
struct user_vfp __user *ufp = data;
- vfp_sync_state(thread);
+ vfp_sync_hwstate(thread);
/* copy the floating point registers */
if (copy_to_user(&ufp->fpregs, &vfp->hard.fpregs,
@@ -686,7 +832,7 @@ static int ptrace_setvfpregs(struct task_struct *tsk, void __user *data)
union vfp_state *vfp = &thread->vfpstate;
struct user_vfp __user *ufp = data;
- vfp_sync_state(thread);
+ vfp_sync_hwstate(thread);
/* copy the floating point registers */
if (copy_from_user(&vfp->hard.fpregs, &ufp->fpregs,
@@ -697,115 +843,282 @@ static int ptrace_setvfpregs(struct task_struct *tsk, void __user *data)
if (get_user(vfp->hard.fpscr, &ufp->fpscr))
return -EFAULT;
+ vfp_flush_hwstate(thread);
+
return 0;
}
#endif
-long arch_ptrace(struct task_struct *child, long request, long addr, long data)
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+/*
+ * Convert a virtual register number into an index for a thread_info
+ * breakpoint array. Breakpoints are identified using positive numbers
+ * whilst watchpoints are negative. The registers are laid out as pairs
+ * of (address, control), each pair mapping to a unique hw_breakpoint struct.
+ * Register 0 is reserved for describing resource information.
+ */
+static int ptrace_hbp_num_to_idx(long num)
{
- int ret;
+ if (num < 0)
+ num = (ARM_MAX_BRP << 1) - num;
+ return (num - 1) >> 1;
+}
- 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;
+/*
+ * Returns the virtual register number for the address of the
+ * breakpoint at index idx.
+ */
+static long ptrace_hbp_idx_to_num(int idx)
+{
+ long mid = ARM_MAX_BRP << 1;
+ long num = (idx << 1) + 1;
+ return num > mid ? mid - num : num;
+}
- case PTRACE_PEEKUSR:
- ret = ptrace_read_user(child, addr, (unsigned long __user *)data);
- break;
+/*
+ * Handle hitting a HW-breakpoint.
+ */
+static void ptrace_hbptriggered(struct perf_event *bp, int unused,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
+ long num;
+ int i;
+ siginfo_t info;
- /*
- * write the word at location addr.
- */
- case PTRACE_POKETEXT:
- case PTRACE_POKEDATA:
- ret = generic_ptrace_pokedata(child, addr, data);
+ for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
+ if (current->thread.debug.hbp[i] == bp)
break;
- case PTRACE_POKEUSR:
- ret = ptrace_write_user(child, addr, data);
- break;
+ num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
- /*
- * continue/restart and stop at next (return from) syscall
- */
- case PTRACE_SYSCALL:
- case PTRACE_CONT:
- ret = -EIO;
- if (!valid_signal(data))
- break;
- if (request == PTRACE_SYSCALL)
- set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- else
- clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- child->exit_code = data;
- single_step_disable(child);
- wake_up_process(child);
- ret = 0;
- break;
+ info.si_signo = SIGTRAP;
+ info.si_errno = (int)num;
+ info.si_code = TRAP_HWBKPT;
+ info.si_addr = (void __user *)(bkpt->trigger);
+
+ force_sig_info(SIGTRAP, &info, current);
+}
+
+/*
+ * Set ptrace breakpoint pointers to zero for this task.
+ * This is required in order to prevent child processes from unregistering
+ * breakpoints held by their parent.
+ */
+void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
+{
+ memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
+}
+
+/*
+ * Unregister breakpoints from this task and reset the pointers in
+ * the thread_struct.
+ */
+void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
+{
+ int i;
+ struct thread_struct *t = &tsk->thread;
+
+ for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
+ if (t->debug.hbp[i]) {
+ unregister_hw_breakpoint(t->debug.hbp[i]);
+ t->debug.hbp[i] = NULL;
+ }
+ }
+}
+
+static u32 ptrace_get_hbp_resource_info(void)
+{
+ u8 num_brps, num_wrps, debug_arch, wp_len;
+ u32 reg = 0;
+
+ num_brps = hw_breakpoint_slots(TYPE_INST);
+ num_wrps = hw_breakpoint_slots(TYPE_DATA);
+ debug_arch = arch_get_debug_arch();
+ wp_len = arch_get_max_wp_len();
+
+ reg |= debug_arch;
+ reg <<= 8;
+ reg |= wp_len;
+ reg <<= 8;
+ reg |= num_wrps;
+ reg <<= 8;
+ reg |= num_brps;
+
+ return reg;
+}
+
+static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
+{
+ struct perf_event_attr attr;
+
+ ptrace_breakpoint_init(&attr);
+
+ /* Initialise fields to sane defaults. */
+ attr.bp_addr = 0;
+ attr.bp_len = HW_BREAKPOINT_LEN_4;
+ attr.bp_type = type;
+ attr.disabled = 1;
+
+ return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, tsk);
+}
+
+static int ptrace_gethbpregs(struct task_struct *tsk, long num,
+ unsigned long __user *data)
+{
+ u32 reg;
+ int idx, ret = 0;
+ struct perf_event *bp;
+ struct arch_hw_breakpoint_ctrl arch_ctrl;
+
+ if (num == 0) {
+ reg = ptrace_get_hbp_resource_info();
+ } else {
+ idx = ptrace_hbp_num_to_idx(num);
+ if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ bp = tsk->thread.debug.hbp[idx];
+ if (!bp) {
+ reg = 0;
+ goto put;
+ }
+
+ arch_ctrl = counter_arch_bp(bp)->ctrl;
/*
- * make the child exit. Best I can do is send it a sigkill.
- * perhaps it should be put in the status that it wants to
- * exit.
+ * Fix up the len because we may have adjusted it
+ * to compensate for an unaligned address.
*/
- case PTRACE_KILL:
- single_step_disable(child);
- if (child->exit_state != EXIT_ZOMBIE) {
- child->exit_code = SIGKILL;
- wake_up_process(child);
- }
- ret = 0;
+ while (!(arch_ctrl.len & 0x1))
+ arch_ctrl.len >>= 1;
+
+ if (idx & 0x1)
+ reg = encode_ctrl_reg(arch_ctrl);
+ else
+ reg = bp->attr.bp_addr;
+ }
+
+put:
+ if (put_user(reg, data))
+ ret = -EFAULT;
+
+out:
+ return ret;
+}
+
+static int ptrace_sethbpregs(struct task_struct *tsk, long num,
+ unsigned long __user *data)
+{
+ int idx, gen_len, gen_type, implied_type, ret = 0;
+ u32 user_val;
+ struct perf_event *bp;
+ struct arch_hw_breakpoint_ctrl ctrl;
+ struct perf_event_attr attr;
+
+ if (num == 0)
+ goto out;
+ else if (num < 0)
+ implied_type = HW_BREAKPOINT_RW;
+ else
+ implied_type = HW_BREAKPOINT_X;
+
+ idx = ptrace_hbp_num_to_idx(num);
+ if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (get_user(user_val, data)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ bp = tsk->thread.debug.hbp[idx];
+ if (!bp) {
+ bp = ptrace_hbp_create(tsk, implied_type);
+ if (IS_ERR(bp)) {
+ ret = PTR_ERR(bp);
+ goto out;
+ }
+ tsk->thread.debug.hbp[idx] = bp;
+ }
+
+ attr = bp->attr;
+
+ if (num & 0x1) {
+ /* Address */
+ attr.bp_addr = user_val;
+ } else {
+ /* Control */
+ decode_ctrl_reg(user_val, &ctrl);
+ ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
+ if (ret)
+ goto out;
+
+ if ((gen_type & implied_type) != gen_type) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ attr.bp_len = gen_len;
+ attr.bp_type = gen_type;
+ attr.disabled = !ctrl.enabled;
+ }
+
+ ret = modify_user_hw_breakpoint(bp, &attr);
+out:
+ return ret;
+}
+#endif
+
+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;
- /*
- * execute single instruction.
- */
- case PTRACE_SINGLESTEP:
- ret = -EIO;
- if (!valid_signal(data))
- break;
- single_step_enable(child);
- clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- child->exit_code = data;
- /* give it a chance to run. */
- wake_up_process(child);
- ret = 0;
+ case PTRACE_POKEUSR:
+ ret = ptrace_write_user(child, addr, data);
break;
case PTRACE_GETREGS:
- ret = ptrace_getregs(child, (void __user *)data);
+ ret = ptrace_getregs(child, datap);
break;
case PTRACE_SETREGS:
- ret = ptrace_setregs(child, (void __user *)data);
+ ret = ptrace_setregs(child, datap);
break;
case PTRACE_GETFPREGS:
- ret = ptrace_getfpregs(child, (void __user *)data);
+ ret = ptrace_getfpregs(child, datap);
break;
case PTRACE_SETFPREGS:
- ret = ptrace_setfpregs(child, (void __user *)data);
+ ret = ptrace_setfpregs(child, datap);
break;
#ifdef CONFIG_IWMMXT
case PTRACE_GETWMMXREGS:
- ret = ptrace_getwmmxregs(child, (void __user *)data);
+ ret = ptrace_getwmmxregs(child, datap);
break;
case PTRACE_SETWMMXREGS:
- ret = ptrace_setwmmxregs(child, (void __user *)data);
+ ret = ptrace_setwmmxregs(child, datap);
break;
#endif
case PTRACE_GET_THREAD_AREA:
ret = put_user(task_thread_info(child)->tp_value,
- (unsigned long __user *) data);
+ datap);
break;
case PTRACE_SET_SYSCALL:
@@ -815,21 +1128,32 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
#ifdef CONFIG_CRUNCH
case PTRACE_GETCRUNCHREGS:
- ret = ptrace_getcrunchregs(child, (void __user *)data);
+ ret = ptrace_getcrunchregs(child, datap);
break;
case PTRACE_SETCRUNCHREGS:
- ret = ptrace_setcrunchregs(child, (void __user *)data);
+ ret = ptrace_setcrunchregs(child, datap);
break;
#endif
#ifdef CONFIG_VFP
case PTRACE_GETVFPREGS:
- ret = ptrace_getvfpregs(child, (void __user *)data);
+ ret = ptrace_getvfpregs(child, datap);
break;
case PTRACE_SETVFPREGS:
- ret = ptrace_setvfpregs(child, (void __user *)data);
+ ret = ptrace_setvfpregs(child, datap);
+ break;
+#endif
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ case PTRACE_GETHBPREGS:
+ ret = ptrace_gethbpregs(child, addr,
+ (unsigned long __user *)data);
+ break;
+ case PTRACE_SETHBPREGS:
+ ret = ptrace_sethbpregs(child, addr,
+ (unsigned long __user *)data);
break;
#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 06:53:41 +0000