x86, bts, mm: clean up buffer allocation
The current mm interface is asymetric. One function allocates a locked
buffer, another function only refunds the memory.
Change this to have two functions for accounting and refunding locked
memory, respectively; and do the actual buffer allocation in ptrace.
[ Impact: refactor BTS buffer allocation code ]
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090424095143.A30265@sedona.ch.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 d5252ae..09ecbde 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -617,17 +617,28 @@
struct work_struct work;
};
-static inline void alloc_bts_buffer(struct bts_context *context,
- unsigned int size)
+static int alloc_bts_buffer(struct bts_context *context, unsigned int size)
{
- void *buffer;
+ void *buffer = NULL;
+ int err = -ENOMEM;
- buffer = alloc_locked_buffer(size);
- if (buffer) {
- context->buffer = buffer;
- context->size = size;
- context->mm = get_task_mm(current);
- }
+ err = account_locked_memory(current->mm, current->signal->rlim, size);
+ if (err < 0)
+ return err;
+
+ buffer = kzalloc(size, GFP_KERNEL);
+ if (!buffer)
+ goto out_refund;
+
+ context->buffer = buffer;
+ context->size = size;
+ context->mm = get_task_mm(current);
+
+ return 0;
+
+ out_refund:
+ refund_locked_memory(current->mm, size);
+ return err;
}
static inline void free_bts_buffer(struct bts_context *context)
@@ -638,7 +649,7 @@
kfree(context->buffer);
context->buffer = NULL;
- refund_locked_buffer_memory(context->mm, context->size);
+ refund_locked_memory(context->mm, context->size);
context->size = 0;
mmput(context->mm);
@@ -786,13 +797,15 @@
context->tracer = NULL;
if ((cfg.flags & PTRACE_BTS_O_ALLOC) && (cfg.size != context->size)) {
+ int err;
+
free_bts_buffer(context);
if (!cfg.size)
return 0;
- alloc_bts_buffer(context, cfg.size);
- if (!context->buffer)
- return -ENOMEM;
+ err = alloc_bts_buffer(context, cfg.size);
+ if (err < 0)
+ return err;
}
if (cfg.flags & PTRACE_BTS_O_TRACE)
