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cris arch-v32: use generic ptrace_resume code

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Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP.  This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.

Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.

The way breakpoints are disabled is entirely inconsistent currently, I
tried to make some sense of it, but I suspect all of the content of
ptrace_disable should be moved into user_disable_single_step, this
defintively needs some revisting as the current patch changes behaviour in
not quite designed ways.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christoph Hellwig 2010-03-10 15:23:00 -08:00 committed by Linus Torvalds
parent 8313809ef3
commit 290ba3aef5
2 changed files with 31 additions and 79 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

109
arch/cris/arch-v32/kernel/ptrace.c
View File

@ -78,6 +78,35 @@ int put_reg(struct task_struct *task, unsigned int regno, unsigned long data)
return 0;
}
void user_enable_single_step(struct task_struct *child)
{
unsigned long tmp;
/*
* Set up SPC if not set already (in which case we have no other
* choice but to trust it).
*/
if (!get_reg(child, PT_SPC)) {
/* In case we're stopped in a delay slot. */
tmp = get_reg(child, PT_ERP) & ~1;
put_reg(child, PT_SPC, tmp);
}
tmp = get_reg(child, PT_CCS) | SBIT_USER;
put_reg(child, PT_CCS, tmp);
}
void user_disable_single_step(struct task_struct *child)
{
put_reg(child, PT_SPC, 0);
if (!get_debugreg(child->pid, PT_BP_CTRL)) {
unsigned long tmp;
/* If no h/w bp configured, disable S bit. */
tmp = get_reg(child, PT_CCS) & ~SBIT_USER;
put_reg(child, PT_CCS, tmp);
}
}
/*
* Called by kernel/ptrace.c when detaching.
*
@ -89,8 +118,7 @@ ptrace_disable(struct task_struct *child)
unsigned long tmp;
/* Deconfigure SPC and S-bit. */
tmp = get_reg(child, PT_CCS) & ~SBIT_USER;
put_reg(child, PT_CCS, tmp);
user_disable_single_step(child);
put_reg(child, PT_SPC, 0);
/* Deconfigure any watchpoints associated with the child. */
@ -169,83 +197,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
ret = 0;
break;
case PTRACE_SYSCALL:
case PTRACE_CONT:
ret = -EIO;
if (!valid_signal(data))
break;
/* Continue means no single-step. */
put_reg(child, PT_SPC, 0);
if (!get_debugreg(child->pid, PT_BP_CTRL)) {
unsigned long tmp;
/* If no h/w bp configured, disable S bit. */
tmp = get_reg(child, PT_CCS) & ~SBIT_USER;
put_reg(child, PT_CCS, tmp);
}
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;
/* TODO: make sure any pending breakpoint is killed */
wake_up_process(child);
ret = 0;
break;
/* Make the child exit by sending it a sigkill. */
case PTRACE_KILL:
ret = 0;
if (child->exit_state == EXIT_ZOMBIE)
break;
child->exit_code = SIGKILL;
/* Deconfigure single-step and h/w bp. */
ptrace_disable(child);
/* TODO: make sure any pending breakpoint is killed */
wake_up_process(child);
break;
/* Set the trap flag. */
case PTRACE_SINGLESTEP: {
unsigned long tmp;
ret = -EIO;
/* Set up SPC if not set already (in which case we have
no other choice but to trust it). */
if (!get_reg(child, PT_SPC)) {
/* In case we're stopped in a delay slot. */
tmp = get_reg(child, PT_ERP) & ~1;
put_reg(child, PT_SPC, tmp);
}
tmp = get_reg(child, PT_CCS) | SBIT_USER;
put_reg(child, PT_CCS, tmp);
if (!valid_signal(data))
break;
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
/* TODO: set some clever breakpoint mechanism... */
child->exit_code = data;
wake_up_process(child);
ret = 0;
break;
}
/* Get all GP registers from the child. */
case PTRACE_GETREGS: {
int i;

1
arch/cris/include/arch-v32/arch/ptrace.h
View File

@ -108,6 +108,7 @@ struct switch_stack {
#ifdef __KERNEL__
#define arch_has_single_step() (1)
#define user_mode(regs) (((regs)->ccs & (1 << (U_CCS_BITNR + CCS_SHIFT))) != 0)
#define instruction_pointer(regs) ((regs)->erp)
extern void show_regs(struct pt_regs *);