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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-03-25 14:51:50 +0100
committerIngo Molnar <mingo@elte.hu>2010-03-26 11:33:55 +0100
commitfaa4602e47690fb11221e00f9b9697c8dc0d4b19 (patch)
treeaf667d1cdff7dc63b6893ee3f27a1f2503229ed1 /arch/x86/kernel/ptrace.c
parent7c5ecaf7666617889f337296c610815b519abfa9 (diff)
x86, perf, bts, mm: Delete the never used BTS-ptrace code
Support for the PMU's BTS features has been upstreamed in v2.6.32, but we still have the old and disabled ptrace-BTS, as Linus noticed it not so long ago. It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without regard for other uses (perf) and doesn't provide the flexibility needed for perf either. Its users are ptrace-block-step and ptrace-bts, since ptrace-bts was never used and ptrace-block-step can be implemented using a much simpler approach. So axe all 3000 lines of it. That includes the *locked_memory*() APIs in mm/mlock.c as well. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Markus Metzger <markus.t.metzger@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20100325135413.938004390@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/ptrace.c')
-rw-r--r--arch/x86/kernel/ptrace.c382
1 files changed, 0 insertions, 382 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index a503b1fd04e5..f2fd3b80e565 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -2,9 +2,6 @@
/*
* Pentium III FXSR, SSE support
* Gareth Hughes <gareth@valinux.com>, May 2000
- *
- * BTS tracing
- * Markus Metzger <markus.t.metzger@intel.com>, Dec 2007
*/
#include <linux/kernel.h>
@@ -21,7 +18,6 @@
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/signal.h>
-#include <linux/workqueue.h>
#include <linux/perf_event.h>
#include <linux/hw_breakpoint.h>
@@ -35,7 +31,6 @@
#include <asm/desc.h>
#include <asm/prctl.h>
#include <asm/proto.h>
-#include <asm/ds.h>
#include <asm/hw_breakpoint.h>
#include "tls.h"
@@ -788,342 +783,6 @@ static int ioperm_get(struct task_struct *target,
0, IO_BITMAP_BYTES);
}
-#ifdef CONFIG_X86_PTRACE_BTS
-/*
- * A branch trace store context.
- *
- * Contexts may only be installed by ptrace_bts_config() and only for
- * ptraced tasks.
- *
- * Contexts are destroyed when the tracee is detached from the tracer.
- * The actual destruction work requires interrupts enabled, so the
- * work is deferred and will be scheduled during __ptrace_unlink().
- *
- * Contexts hold an additional task_struct reference on the traced
- * task, as well as a reference on the tracer's mm.
- *
- * Ptrace already holds a task_struct for the duration of ptrace operations,
- * but since destruction is deferred, it may be executed after both
- * tracer and tracee exited.
- */
-struct bts_context {
- /* The branch trace handle. */
- struct bts_tracer *tracer;
-
- /* The buffer used to store the branch trace and its size. */
- void *buffer;
- unsigned int size;
-
- /* The mm that paid for the above buffer. */
- struct mm_struct *mm;
-
- /* The task this context belongs to. */
- struct task_struct *task;
-
- /* The signal to send on a bts buffer overflow. */
- unsigned int bts_ovfl_signal;
-
- /* The work struct to destroy a context. */
- struct work_struct work;
-};
-
-static int alloc_bts_buffer(struct bts_context *context, unsigned int size)
-{
- void *buffer = NULL;
- int err = -ENOMEM;
-
- 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)
-{
- if (!context->buffer)
- return;
-
- kfree(context->buffer);
- context->buffer = NULL;
-
- refund_locked_memory(context->mm, context->size);
- context->size = 0;
-
- mmput(context->mm);
- context->mm = NULL;
-}
-
-static void free_bts_context_work(struct work_struct *w)
-{
- struct bts_context *context;
-
- context = container_of(w, struct bts_context, work);
-
- ds_release_bts(context->tracer);
- put_task_struct(context->task);
- free_bts_buffer(context);
- kfree(context);
-}
-
-static inline void free_bts_context(struct bts_context *context)
-{
- INIT_WORK(&context->work, free_bts_context_work);
- schedule_work(&context->work);
-}
-
-static inline struct bts_context *alloc_bts_context(struct task_struct *task)
-{
- struct bts_context *context = kzalloc(sizeof(*context), GFP_KERNEL);
- if (context) {
- context->task = task;
- task->bts = context;
-
- get_task_struct(task);
- }
-
- return context;
-}
-
-static int ptrace_bts_read_record(struct task_struct *child, size_t index,
- struct bts_struct __user *out)
-{
- struct bts_context *context;
- const struct bts_trace *trace;
- struct bts_struct bts;
- const unsigned char *at;
- int error;
-
- context = child->bts;
- if (!context)
- return -ESRCH;
-
- trace = ds_read_bts(context->tracer);
- if (!trace)
- return -ESRCH;
-
- at = trace->ds.top - ((index + 1) * trace->ds.size);
- if ((void *)at < trace->ds.begin)
- at += (trace->ds.n * trace->ds.size);
-
- if (!trace->read)
- return -EOPNOTSUPP;
-
- error = trace->read(context->tracer, at, &bts);
- if (error < 0)
- return error;
-
- if (copy_to_user(out, &bts, sizeof(bts)))
- return -EFAULT;
-
- return sizeof(bts);
-}
-
-static int ptrace_bts_drain(struct task_struct *child,
- long size,
- struct bts_struct __user *out)
-{
- struct bts_context *context;
- const struct bts_trace *trace;
- const unsigned char *at;
- int error, drained = 0;
-
- context = child->bts;
- if (!context)
- return -ESRCH;
-
- trace = ds_read_bts(context->tracer);
- if (!trace)
- return -ESRCH;
-
- if (!trace->read)
- return -EOPNOTSUPP;
-
- if (size < (trace->ds.top - trace->ds.begin))
- return -EIO;
-
- for (at = trace->ds.begin; (void *)at < trace->ds.top;
- out++, drained++, at += trace->ds.size) {
- struct bts_struct bts;
-
- error = trace->read(context->tracer, at, &bts);
- if (error < 0)
- return error;
-
- if (copy_to_user(out, &bts, sizeof(bts)))
- return -EFAULT;
- }
-
- memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
-
- error = ds_reset_bts(context->tracer);
- if (error < 0)
- return error;
-
- return drained;
-}
-
-static int ptrace_bts_config(struct task_struct *child,
- long cfg_size,
- const struct ptrace_bts_config __user *ucfg)
-{
- struct bts_context *context;
- struct ptrace_bts_config cfg;
- unsigned int flags = 0;
-
- if (cfg_size < sizeof(cfg))
- return -EIO;
-
- if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
- return -EFAULT;
-
- context = child->bts;
- if (!context)
- context = alloc_bts_context(child);
- if (!context)
- return -ENOMEM;
-
- if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
- if (!cfg.signal)
- return -EINVAL;
-
- return -EOPNOTSUPP;
- context->bts_ovfl_signal = cfg.signal;
- }
-
- ds_release_bts(context->tracer);
- 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;
-
- err = alloc_bts_buffer(context, cfg.size);
- if (err < 0)
- return err;
- }
-
- if (cfg.flags & PTRACE_BTS_O_TRACE)
- flags |= BTS_USER;
-
- if (cfg.flags & PTRACE_BTS_O_SCHED)
- flags |= BTS_TIMESTAMPS;
-
- context->tracer =
- ds_request_bts_task(child, context->buffer, context->size,
- NULL, (size_t)-1, flags);
- if (unlikely(IS_ERR(context->tracer))) {
- int error = PTR_ERR(context->tracer);
-
- free_bts_buffer(context);
- context->tracer = NULL;
- return error;
- }
-
- return sizeof(cfg);
-}
-
-static int ptrace_bts_status(struct task_struct *child,
- long cfg_size,
- struct ptrace_bts_config __user *ucfg)
-{
- struct bts_context *context;
- const struct bts_trace *trace;
- struct ptrace_bts_config cfg;
-
- context = child->bts;
- if (!context)
- return -ESRCH;
-
- if (cfg_size < sizeof(cfg))
- return -EIO;
-
- trace = ds_read_bts(context->tracer);
- if (!trace)
- return -ESRCH;
-
- memset(&cfg, 0, sizeof(cfg));
- cfg.size = trace->ds.end - trace->ds.begin;
- cfg.signal = context->bts_ovfl_signal;
- cfg.bts_size = sizeof(struct bts_struct);
-
- if (cfg.signal)
- cfg.flags |= PTRACE_BTS_O_SIGNAL;
-
- if (trace->ds.flags & BTS_USER)
- cfg.flags |= PTRACE_BTS_O_TRACE;
-
- if (trace->ds.flags & BTS_TIMESTAMPS)
- cfg.flags |= PTRACE_BTS_O_SCHED;
-
- if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
- return -EFAULT;
-
- return sizeof(cfg);
-}
-
-static int ptrace_bts_clear(struct task_struct *child)
-{
- struct bts_context *context;
- const struct bts_trace *trace;
-
- context = child->bts;
- if (!context)
- return -ESRCH;
-
- trace = ds_read_bts(context->tracer);
- if (!trace)
- return -ESRCH;
-
- memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
-
- return ds_reset_bts(context->tracer);
-}
-
-static int ptrace_bts_size(struct task_struct *child)
-{
- struct bts_context *context;
- const struct bts_trace *trace;
-
- context = child->bts;
- if (!context)
- return -ESRCH;
-
- trace = ds_read_bts(context->tracer);
- if (!trace)
- return -ESRCH;
-
- return (trace->ds.top - trace->ds.begin) / trace->ds.size;
-}
-
-/*
- * Called from __ptrace_unlink() after the child has been moved back
- * to its original parent.
- */
-void ptrace_bts_untrace(struct task_struct *child)
-{
- if (unlikely(child->bts)) {
- free_bts_context(child->bts);
- child->bts = NULL;
- }
-}
-#endif /* CONFIG_X86_PTRACE_BTS */
-
/*
* Called by kernel/ptrace.c when detaching..
*
@@ -1251,39 +910,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
break;
#endif
- /*
- * These bits need more cooking - not enabled yet:
- */
-#ifdef CONFIG_X86_PTRACE_BTS
- case PTRACE_BTS_CONFIG:
- ret = ptrace_bts_config
- (child, data, (struct ptrace_bts_config __user *)addr);
- break;
-
- case PTRACE_BTS_STATUS:
- ret = ptrace_bts_status
- (child, data, (struct ptrace_bts_config __user *)addr);
- break;
-
- case PTRACE_BTS_SIZE:
- ret = ptrace_bts_size(child);
- break;
-
- case PTRACE_BTS_GET:
- ret = ptrace_bts_read_record
- (child, data, (struct bts_struct __user *) addr);
- break;
-
- case PTRACE_BTS_CLEAR:
- ret = ptrace_bts_clear(child);
- break;
-
- case PTRACE_BTS_DRAIN:
- ret = ptrace_bts_drain
- (child, data, (struct bts_struct __user *) addr);
- break;
-#endif /* CONFIG_X86_PTRACE_BTS */
-
default:
ret = ptrace_request(child, request, addr, data);
break;
@@ -1543,14 +1169,6 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
case PTRACE_GET_THREAD_AREA:
case PTRACE_SET_THREAD_AREA:
-#ifdef CONFIG_X86_PTRACE_BTS
- case PTRACE_BTS_CONFIG:
- case PTRACE_BTS_STATUS:
- case PTRACE_BTS_SIZE:
- case PTRACE_BTS_GET:
- case PTRACE_BTS_CLEAR:
- case PTRACE_BTS_DRAIN:
-#endif /* CONFIG_X86_PTRACE_BTS */
return arch_ptrace(child, request, addr, data);
default: