x86, bts, ptrace: move BTS buffer allocation from ds.c into ptrace.c
Impact: restructure DS memory allocation to be done by the usage site of DS
Require pre-allocated buffers in ds.h.
Move the BTS buffer allocation for ptrace into ptrace.c.
The pointer to the allocated buffer is stored in the traced task's
task_struct together with the handle returned by ds_request_bts().
Removes memory accounting code.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 76adf5b..2c8ec1b 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -758,6 +758,10 @@
bts_ovfl_callback_t ovfl = NULL;
unsigned int sig = 0;
+ error = -EINVAL;
+ if (cfg.size < (10 * bts_cfg.sizeof_bts))
+ goto errout;
+
if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
if (!cfg.signal)
goto errout;
@@ -768,14 +772,26 @@
sig = cfg.signal;
}
- if (child->bts)
+ if (child->bts) {
(void)ds_release_bts(child->bts);
+ kfree(child->bts_buffer);
- child->bts = ds_request_bts(child, /* base = */ NULL, cfg.size,
+ child->bts = NULL;
+ child->bts_buffer = NULL;
+ }
+
+ error = -ENOMEM;
+ child->bts_buffer = kzalloc(cfg.size, GFP_KERNEL);
+ if (!child->bts_buffer)
+ goto errout;
+
+ child->bts = ds_request_bts(child, child->bts_buffer, cfg.size,
ovfl, /* th = */ (size_t)-1);
if (IS_ERR(child->bts)) {
error = PTR_ERR(child->bts);
+ kfree(child->bts_buffer);
child->bts = NULL;
+ child->bts_buffer = NULL;
goto errout;
}
@@ -972,6 +988,8 @@
#ifdef CONFIG_X86_PTRACE_BTS
if (child->bts) {
(void)ds_release_bts(child->bts);
+ kfree(child->bts_buffer);
+ child->bts_buffer = NULL;
child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
if (!child->thread.debugctlmsr)