[S390] ptrace cleanup
Overhaul program event recording and the code dealing with the ptrace
user space interface.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 019bb71..ef86ad2 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -1,25 +1,9 @@
/*
- * arch/s390/kernel/ptrace.c
+ * Ptrace user space interface.
*
- * S390 version
- * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
- * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
+ * Copyright IBM Corp. 1999,2010
+ * Author(s): Denis Joseph Barrow
* Martin Schwidefsky (schwidefsky@de.ibm.com)
- *
- * Based on PowerPC version
- * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
- *
- * Derived from "arch/m68k/kernel/ptrace.c"
- * Copyright (C) 1994 by Hamish Macdonald
- * Taken from linux/kernel/ptrace.c and modified for M680x0.
- * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
- *
- * Modified by Cort Dougan (cort@cs.nmt.edu)
- *
- *
- * This file is subject to the terms and conditions of the GNU General
- * Public License. See the file README.legal in the main directory of
- * this archive for more details.
*/
#include <linux/kernel.h>
@@ -61,76 +45,58 @@
REGSET_GENERAL_EXTENDED,
};
-static void
-FixPerRegisters(struct task_struct *task)
+void update_per_regs(struct task_struct *task)
{
- struct pt_regs *regs;
- per_struct *per_info;
- per_cr_words cr_words;
+ static const struct per_regs per_single_step = {
+ .control = PER_EVENT_IFETCH,
+ .start = 0,
+ .end = PSW_ADDR_INSN,
+ };
+ struct pt_regs *regs = task_pt_regs(task);
+ struct thread_struct *thread = &task->thread;
+ const struct per_regs *new;
+ struct per_regs old;
- regs = task_pt_regs(task);
- per_info = (per_struct *) &task->thread.per_info;
- per_info->control_regs.bits.em_instruction_fetch =
- per_info->single_step | per_info->instruction_fetch;
-
- if (per_info->single_step) {
- per_info->control_regs.bits.starting_addr = 0;
-#ifdef CONFIG_COMPAT
- if (is_compat_task())
- per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
- else
-#endif
- per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
- } else {
- per_info->control_regs.bits.starting_addr =
- per_info->starting_addr;
- per_info->control_regs.bits.ending_addr =
- per_info->ending_addr;
- }
- /*
- * if any of the control reg tracing bits are on
- * we switch on per in the psw
- */
- if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
- regs->psw.mask |= PSW_MASK_PER;
- else
+ /* TIF_SINGLE_STEP overrides the user specified PER registers. */
+ new = test_tsk_thread_flag(task, TIF_SINGLE_STEP) ?
+ &per_single_step : &thread->per_user;
+
+ /* Take care of the PER enablement bit in the PSW. */
+ if (!(new->control & PER_EVENT_MASK)) {
regs->psw.mask &= ~PSW_MASK_PER;
-
- if (per_info->control_regs.bits.em_storage_alteration)
- per_info->control_regs.bits.storage_alt_space_ctl = 1;
- else
- per_info->control_regs.bits.storage_alt_space_ctl = 0;
-
- if (task == current) {
- __ctl_store(cr_words, 9, 11);
- if (memcmp(&cr_words, &per_info->control_regs.words,
- sizeof(cr_words)) != 0)
- __ctl_load(per_info->control_regs.words, 9, 11);
+ return;
}
+ regs->psw.mask |= PSW_MASK_PER;
+ __ctl_store(old, 9, 11);
+ if (memcmp(new, &old, sizeof(struct per_regs)) != 0)
+ __ctl_load(*new, 9, 11);
}
void user_enable_single_step(struct task_struct *task)
{
- task->thread.per_info.single_step = 1;
- FixPerRegisters(task);
+ set_tsk_thread_flag(task, TIF_SINGLE_STEP);
+ if (task == current)
+ update_per_regs(task);
}
void user_disable_single_step(struct task_struct *task)
{
- task->thread.per_info.single_step = 0;
- FixPerRegisters(task);
+ clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
+ if (task == current)
+ update_per_regs(task);
}
/*
* Called by kernel/ptrace.c when detaching..
*
- * Make sure single step bits etc are not set.
+ * Clear all debugging related fields.
*/
-void
-ptrace_disable(struct task_struct *child)
+void ptrace_disable(struct task_struct *task)
{
- /* make sure the single step bit is not set. */
- user_disable_single_step(child);
+ memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
+ memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
+ clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
+ clear_tsk_thread_flag(task, TIF_PER_TRAP);
}
#ifndef CONFIG_64BIT
@@ -139,6 +105,47 @@
# define __ADDR_MASK 7
#endif
+static inline unsigned long __peek_user_per(struct task_struct *child,
+ addr_t addr)
+{
+ struct per_struct_kernel *dummy = NULL;
+
+ if (addr == (addr_t) &dummy->cr9)
+ /* Control bits of the active per set. */
+ return test_thread_flag(TIF_SINGLE_STEP) ?
+ PER_EVENT_IFETCH : child->thread.per_user.control;
+ else if (addr == (addr_t) &dummy->cr10)
+ /* Start address of the active per set. */
+ return test_thread_flag(TIF_SINGLE_STEP) ?
+ 0 : child->thread.per_user.start;
+ else if (addr == (addr_t) &dummy->cr11)
+ /* End address of the active per set. */
+ return test_thread_flag(TIF_SINGLE_STEP) ?
+ PSW_ADDR_INSN : child->thread.per_user.end;
+ else if (addr == (addr_t) &dummy->bits)
+ /* Single-step bit. */
+ return test_thread_flag(TIF_SINGLE_STEP) ?
+ (1UL << (BITS_PER_LONG - 1)) : 0;
+ else if (addr == (addr_t) &dummy->starting_addr)
+ /* Start address of the user specified per set. */
+ return child->thread.per_user.start;
+ else if (addr == (addr_t) &dummy->ending_addr)
+ /* End address of the user specified per set. */
+ return child->thread.per_user.end;
+ else if (addr == (addr_t) &dummy->perc_atmid)
+ /* PER code, ATMID and AI of the last PER trap */
+ return (unsigned long)
+ child->thread.per_event.cause << (BITS_PER_LONG - 16);
+ else if (addr == (addr_t) &dummy->address)
+ /* Address of the last PER trap */
+ return child->thread.per_event.address;
+ else if (addr == (addr_t) &dummy->access_id)
+ /* Access id of the last PER trap */
+ return (unsigned long)
+ child->thread.per_event.paid << (BITS_PER_LONG - 8);
+ return 0;
+}
+
/*
* Read the word at offset addr from the user area of a process. The
* trouble here is that the information is littered over different
@@ -204,10 +211,10 @@
} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
/*
- * per_info is found in the thread structure
+ * Handle access to the per_info structure.
*/
- offset = addr - (addr_t) &dummy->regs.per_info;
- tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
+ addr -= (addr_t) &dummy->regs.per_info;
+ tmp = __peek_user_per(child, addr);
} else
tmp = 0;
@@ -237,6 +244,35 @@
return put_user(tmp, (addr_t __user *) data);
}
+static inline void __poke_user_per(struct task_struct *child,
+ addr_t addr, addr_t data)
+{
+ struct per_struct_kernel *dummy = NULL;
+
+ /*
+ * There are only three fields in the per_info struct that the
+ * debugger user can write to.
+ * 1) cr9: the debugger wants to set a new PER event mask
+ * 2) starting_addr: the debugger wants to set a new starting
+ * address to use with the PER event mask.
+ * 3) ending_addr: the debugger wants to set a new ending
+ * address to use with the PER event mask.
+ * The user specified PER event mask and the start and end
+ * addresses are used only if single stepping is not in effect.
+ * Writes to any other field in per_info are ignored.
+ */
+ if (addr == (addr_t) &dummy->cr9)
+ /* PER event mask of the user specified per set. */
+ child->thread.per_user.control =
+ data & (PER_EVENT_MASK | PER_CONTROL_MASK);
+ else if (addr == (addr_t) &dummy->starting_addr)
+ /* Starting address of the user specified per set. */
+ child->thread.per_user.start = data;
+ else if (addr == (addr_t) &dummy->ending_addr)
+ /* Ending address of the user specified per set. */
+ child->thread.per_user.end = data;
+}
+
/*
* Write a word to the user area of a process at location addr. This
* operation does have an additional problem compared to peek_user.
@@ -311,19 +347,17 @@
} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
/*
- * per_info is found in the thread structure
+ * Handle access to the per_info structure.
*/
- offset = addr - (addr_t) &dummy->regs.per_info;
- *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
+ addr -= (addr_t) &dummy->regs.per_info;
+ __poke_user_per(child, addr, data);
}
- FixPerRegisters(child);
return 0;
}
-static int
-poke_user(struct task_struct *child, addr_t addr, addr_t data)
+static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
{
addr_t mask;
@@ -410,12 +444,53 @@
*/
/*
+ * Same as peek_user_per but for a 31 bit program.
+ */
+static inline __u32 __peek_user_per_compat(struct task_struct *child,
+ addr_t addr)
+{
+ struct compat_per_struct_kernel *dummy32 = NULL;
+
+ if (addr == (addr_t) &dummy32->cr9)
+ /* Control bits of the active per set. */
+ return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
+ PER_EVENT_IFETCH : child->thread.per_user.control;
+ else if (addr == (addr_t) &dummy32->cr10)
+ /* Start address of the active per set. */
+ return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
+ 0 : child->thread.per_user.start;
+ else if (addr == (addr_t) &dummy32->cr11)
+ /* End address of the active per set. */
+ return test_thread_flag(TIF_SINGLE_STEP) ?
+ PSW32_ADDR_INSN : child->thread.per_user.end;
+ else if (addr == (addr_t) &dummy32->bits)
+ /* Single-step bit. */
+ return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
+ 0x80000000 : 0;
+ else if (addr == (addr_t) &dummy32->starting_addr)
+ /* Start address of the user specified per set. */
+ return (__u32) child->thread.per_user.start;
+ else if (addr == (addr_t) &dummy32->ending_addr)
+ /* End address of the user specified per set. */
+ return (__u32) child->thread.per_user.end;
+ else if (addr == (addr_t) &dummy32->perc_atmid)
+ /* PER code, ATMID and AI of the last PER trap */
+ return (__u32) child->thread.per_event.cause << 16;
+ else if (addr == (addr_t) &dummy32->address)
+ /* Address of the last PER trap */
+ return (__u32) child->thread.per_event.address;
+ else if (addr == (addr_t) &dummy32->access_id)
+ /* Access id of the last PER trap */
+ return (__u32) child->thread.per_event.paid << 24;
+ return 0;
+}
+
+/*
* Same as peek_user but for a 31 bit program.
*/
static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
{
- struct user32 *dummy32 = NULL;
- per_struct32 *dummy_per32 = NULL;
+ struct compat_user *dummy32 = NULL;
addr_t offset;
__u32 tmp;
@@ -465,19 +540,10 @@
} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
/*
- * per_info is found in the thread structure
+ * Handle access to the per_info structure.
*/
- offset = addr - (addr_t) &dummy32->regs.per_info;
- /* This is magic. See per_struct and per_struct32. */
- if ((offset >= (addr_t) &dummy_per32->control_regs &&
- offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
- (offset >= (addr_t) &dummy_per32->starting_addr &&
- offset <= (addr_t) &dummy_per32->ending_addr) ||
- offset == (addr_t) &dummy_per32->lowcore.words.address)
- offset = offset*2 + 4;
- else
- offset = offset*2;
- tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
+ addr -= (addr_t) &dummy32->regs.per_info;
+ tmp = __peek_user_per_compat(child, addr);
} else
tmp = 0;
@@ -498,13 +564,32 @@
}
/*
+ * Same as poke_user_per but for a 31 bit program.
+ */
+static inline void __poke_user_per_compat(struct task_struct *child,
+ addr_t addr, __u32 data)
+{
+ struct compat_per_struct_kernel *dummy32 = NULL;
+
+ if (addr == (addr_t) &dummy32->cr9)
+ /* PER event mask of the user specified per set. */
+ child->thread.per_user.control =
+ data & (PER_EVENT_MASK | PER_CONTROL_MASK);
+ else if (addr == (addr_t) &dummy32->starting_addr)
+ /* Starting address of the user specified per set. */
+ child->thread.per_user.start = data;
+ else if (addr == (addr_t) &dummy32->ending_addr)
+ /* Ending address of the user specified per set. */
+ child->thread.per_user.end = data;
+}
+
+/*
* Same as poke_user but for a 31 bit program.
*/
static int __poke_user_compat(struct task_struct *child,
addr_t addr, addr_t data)
{
- struct user32 *dummy32 = NULL;
- per_struct32 *dummy_per32 = NULL;
+ struct compat_user *dummy32 = NULL;
__u32 tmp = (__u32) data;
addr_t offset;
@@ -561,37 +646,20 @@
} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
/*
- * per_info is found in the thread structure.
+ * Handle access to the per_info structure.
*/
- offset = addr - (addr_t) &dummy32->regs.per_info;
- /*
- * This is magic. See per_struct and per_struct32.
- * By incident the offsets in per_struct are exactly
- * twice the offsets in per_struct32 for all fields.
- * The 8 byte fields need special handling though,
- * because the second half (bytes 4-7) is needed and
- * not the first half.
- */
- if ((offset >= (addr_t) &dummy_per32->control_regs &&
- offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
- (offset >= (addr_t) &dummy_per32->starting_addr &&
- offset <= (addr_t) &dummy_per32->ending_addr) ||
- offset == (addr_t) &dummy_per32->lowcore.words.address)
- offset = offset*2 + 4;
- else
- offset = offset*2;
- *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
-
+ addr -= (addr_t) &dummy32->regs.per_info;
+ __poke_user_per_compat(child, addr, data);
}
- FixPerRegisters(child);
return 0;
}
static int poke_user_compat(struct task_struct *child,
addr_t addr, addr_t data)
{
- if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
+ if (!is_compat_task() || (addr & 3) ||
+ addr > sizeof(struct compat_user) - 3)
return -EIO;
return __poke_user_compat(child, addr, data);
@@ -602,7 +670,7 @@
{
unsigned long addr = caddr;
unsigned long data = cdata;
- ptrace_area_emu31 parea;
+ compat_ptrace_area parea;
int copied, ret;
switch (request) {