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x86, ptrace: rlimit BTS buffer allocation 

Check the rlimit of the tracing task for total and locked memory when allocating the BTS buffer.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Markus Metzger 2008-01-30 13:32:03 +01:00 committed by Ingo Molnar
parent 59e87cdcd2
commit da35c37198
1 changed files with 103 additions and 46 deletions
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149
arch/x86/kernel/ptrace.c
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@ -620,12 +620,80 @@ static int ptrace_bts_drain(struct task_struct *child,
return i;
}
static int ptrace_bts_realloc(struct task_struct *child,
int size, int reduce_size)
{
unsigned long rlim, vm;
int ret, old_size;
if (size < 0)
return -EINVAL;
old_size = ds_get_bts_size((void *)child->thread.ds_area_msr);
if (old_size < 0)
return old_size;
ret = ds_free((void **)&child->thread.ds_area_msr);
if (ret < 0)
goto out;
size >>= PAGE_SHIFT;
old_size >>= PAGE_SHIFT;
current->mm->total_vm -= old_size;
current->mm->locked_vm -= old_size;
if (size == 0)
goto out;
rlim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
vm = current->mm->total_vm + size;
if (rlim < vm) {
ret = -ENOMEM;
if (!reduce_size)
goto out;
size = rlim - current->mm->total_vm;
if (size <= 0)
goto out;
}
rlim = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
vm = current->mm->locked_vm + size;
if (rlim < vm) {
ret = -ENOMEM;
if (!reduce_size)
goto out;
size = rlim - current->mm->locked_vm;
if (size <= 0)
goto out;
}
ret = ds_allocate((void **)&child->thread.ds_area_msr,
size << PAGE_SHIFT);
if (ret < 0)
goto out;
current->mm->total_vm += size;
current->mm->locked_vm += size;
out:
if (child->thread.ds_area_msr)
set_tsk_thread_flag(child, TIF_DS_AREA_MSR);
else
clear_tsk_thread_flag(child, TIF_DS_AREA_MSR);
return ret;
}
static int ptrace_bts_config(struct task_struct *child,
const struct ptrace_bts_config __user *ucfg)
{
struct ptrace_bts_config cfg;
unsigned long debugctl_mask;
int bts_size, ret;
int bts_size, ret = 0;
void *ds;
if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
@ -638,59 +706,46 @@ static int ptrace_bts_config(struct task_struct *child,
if (bts_size < 0)
return bts_size;
}
cfg.size = PAGE_ALIGN(cfg.size);
if (bts_size != cfg.size) {
ret = ds_free((void **)&child->thread.ds_area_msr);
ret = ptrace_bts_realloc(child, cfg.size,
cfg.flags & PTRACE_BTS_O_CUT_SIZE);
if (ret < 0)
return ret;
goto errout;
if (cfg.size > 0)
ret = ds_allocate((void **)&child->thread.ds_area_msr,
cfg.size);
ds = (void *)child->thread.ds_area_msr;
if (ds)
set_tsk_thread_flag(child, TIF_DS_AREA_MSR);
else
clear_tsk_thread_flag(child, TIF_DS_AREA_MSR);
if (ret < 0)
return ret;
bts_size = ds_get_bts_size(ds);
if (bts_size <= 0)
return bts_size;
}
if (ds) {
if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
ret = ds_set_overflow(ds, DS_O_SIGNAL);
} else {
ret = ds_set_overflow(ds, DS_O_WRAP);
}
if (ret < 0)
return ret;
}
if (cfg.flags & PTRACE_BTS_O_SIGNAL)
ret = ds_set_overflow(ds, DS_O_SIGNAL);
else
ret = ds_set_overflow(ds, DS_O_WRAP);
if (ret < 0)
goto errout;
debugctl_mask = ds_debugctl_mask();
if (ds && (cfg.flags & PTRACE_BTS_O_TRACE)) {
child->thread.debugctlmsr |= debugctl_mask;
set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
} else {
/* there is no way for us to check whether we 'own'
* the respective bits in the DEBUGCTL MSR, we're
* about to clear */
child->thread.debugctlmsr &= ~debugctl_mask;
if (cfg.flags & PTRACE_BTS_O_TRACE)
child->thread.debugctlmsr |= ds_debugctl_mask();
else
child->thread.debugctlmsr &= ~ds_debugctl_mask();
if (!child->thread.debugctlmsr)
clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
}
if (ds && (cfg.flags & PTRACE_BTS_O_SCHED))
if (cfg.flags & PTRACE_BTS_O_SCHED)
set_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
else
clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
return 0;
out:
if (child->thread.debugctlmsr)
set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
else
clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
return ret;
errout:
child->thread.debugctlmsr &= ~ds_debugctl_mask();
clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
goto out;
}
static int ptrace_bts_status(struct task_struct *child,
@ -726,7 +781,7 @@ void ptrace_bts_take_timestamp(struct task_struct *tsk,
{
struct bts_struct rec = {
.qualifier = qualifier,
.variant.jiffies = jiffies
.variant.jiffies = jiffies_64
};
ptrace_bts_write_record(tsk, &rec);
@ -743,10 +798,12 @@ void ptrace_disable(struct task_struct *child)
#ifdef TIF_SYSCALL_EMU
clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
#endif
ptrace_bts_config(child, /* options = */ 0);
if (child->thread.ds_area_msr) {
ds_free((void **)&child->thread.ds_area_msr);
clear_tsk_thread_flag(child, TIF_DS_AREA_MSR);
ptrace_bts_realloc(child, 0, 0);
child->thread.debugctlmsr &= ~ds_debugctl_mask();
if (!child->thread.debugctlmsr)
clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
}
}