Merge branches 'x86/acpi', 'x86/asm', 'x86/cpudetect', 'x86/crashdump', 'x86/debug...
[pandora-kernel.git] / arch / x86 / kernel / ptrace.c
index 2c8ec1b..7ec39ab 100644 (file)
@@ -75,10 +75,7 @@ static inline bool invalid_selector(u16 value)
 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 {
        BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
-       regno >>= 2;
-       if (regno > FS)
-               --regno;
-       return &regs->bx + regno;
+       return &regs->bx + (regno >> 2);
 }
 
 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
@@ -90,9 +87,10 @@ static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
        if (offset != offsetof(struct user_regs_struct, gs))
                retval = *pt_regs_access(task_pt_regs(task), offset);
        else {
-               retval = task->thread.gs;
                if (task == current)
-                       savesegment(gs, retval);
+                       retval = get_user_gs(task_pt_regs(task));
+               else
+                       retval = task_user_gs(task);
        }
        return retval;
 }
@@ -126,13 +124,10 @@ static int set_segment_reg(struct task_struct *task,
                break;
 
        case offsetof(struct user_regs_struct, gs):
-               task->thread.gs = value;
                if (task == current)
-                       /*
-                        * The user-mode %gs is not affected by
-                        * kernel entry, so we must update the CPU.
-                        */
-                       loadsegment(gs, value);
+                       set_user_gs(task_pt_regs(task), value);
+               else
+                       task_user_gs(task) = value;
        }
 
        return 0;
@@ -581,153 +576,91 @@ static int ioperm_get(struct task_struct *target,
 }
 
 #ifdef CONFIG_X86_PTRACE_BTS
-/*
- * The configuration for a particular BTS hardware implementation.
- */
-struct bts_configuration {
-       /* the size of a BTS record in bytes; at most BTS_MAX_RECORD_SIZE */
-       unsigned char  sizeof_bts;
-       /* the size of a field in the BTS record in bytes */
-       unsigned char  sizeof_field;
-       /* a bitmask to enable/disable BTS in DEBUGCTL MSR */
-       unsigned long debugctl_mask;
-};
-static struct bts_configuration bts_cfg;
-
-#define BTS_MAX_RECORD_SIZE (8 * 3)
-
-
-/*
- * Branch Trace Store (BTS) uses the following format. Different
- * architectures vary in the size of those fields.
- * - source linear address
- * - destination linear address
- * - flags
- *
- * Later architectures use 64bit pointers throughout, whereas earlier
- * architectures use 32bit pointers in 32bit mode.
- *
- * We compute the base address for the first 8 fields based on:
- * - the field size stored in the DS configuration
- * - the relative field position
- *
- * In order to store additional information in the BTS buffer, we use
- * a special source address to indicate that the record requires
- * special interpretation.
- *
- * Netburst indicated via a bit in the flags field whether the branch
- * was predicted; this is ignored.
- */
-
-enum bts_field {
-       bts_from = 0,
-       bts_to,
-       bts_flags,
-
-       bts_escape = (unsigned long)-1,
-       bts_qual = bts_to,
-       bts_jiffies = bts_flags
-};
-
-static inline unsigned long bts_get(const char *base, enum bts_field field)
-{
-       base += (bts_cfg.sizeof_field * field);
-       return *(unsigned long *)base;
-}
-
-static inline void bts_set(char *base, enum bts_field field, unsigned long val)
-{
-       base += (bts_cfg.sizeof_field * field);;
-       (*(unsigned long *)base) = val;
-}
-
-/*
- * Translate a BTS record from the raw format into the bts_struct format
- *
- * out (out): bts_struct interpretation
- * raw: raw BTS record
- */
-static void ptrace_bts_translate_record(struct bts_struct *out, const void *raw)
-{
-       memset(out, 0, sizeof(*out));
-       if (bts_get(raw, bts_from) == bts_escape) {
-               out->qualifier       = bts_get(raw, bts_qual);
-               out->variant.jiffies = bts_get(raw, bts_jiffies);
-       } else {
-               out->qualifier = BTS_BRANCH;
-               out->variant.lbr.from_ip = bts_get(raw, bts_from);
-               out->variant.lbr.to_ip   = bts_get(raw, bts_to);
-       }
-}
-
 static int ptrace_bts_read_record(struct task_struct *child, size_t index,
                                  struct bts_struct __user *out)
 {
-       struct bts_struct ret;
-       const void *bts_record;
-       size_t bts_index, bts_end;
+       const struct bts_trace *trace;
+       struct bts_struct bts;
+       const unsigned char *at;
        int error;
 
-       error = ds_get_bts_end(child->bts, &bts_end);
-       if (error < 0)
-               return error;
-
-       if (bts_end <= index)
-               return -EINVAL;
+       trace = ds_read_bts(child->bts);
+       if (!trace)
+               return -EPERM;
 
-       error = ds_get_bts_index(child->bts, &bts_index);
-       if (error < 0)
-               return error;
+       at = trace->ds.top - ((index + 1) * trace->ds.size);
+       if ((void *)at < trace->ds.begin)
+               at += (trace->ds.n * trace->ds.size);
 
-       /* translate the ptrace bts index into the ds bts index */
-       bts_index += bts_end - (index + 1);
-       if (bts_end <= bts_index)
-               bts_index -= bts_end;
+       if (!trace->read)
+               return -EOPNOTSUPP;
 
-       error = ds_access_bts(child->bts, bts_index, &bts_record);
+       error = trace->read(child->bts, at, &bts);
        if (error < 0)
                return error;
 
-       ptrace_bts_translate_record(&ret, bts_record);
-
-       if (copy_to_user(out, &ret, sizeof(ret)))
+       if (copy_to_user(out, &bts, sizeof(bts)))
                return -EFAULT;
 
-       return sizeof(ret);
+       return sizeof(bts);
 }
 
 static int ptrace_bts_drain(struct task_struct *child,
                            long size,
                            struct bts_struct __user *out)
 {
-       struct bts_struct ret;
-       const unsigned char *raw;
-       size_t end, i;
-       int error;
+       const struct bts_trace *trace;
+       const unsigned char *at;
+       int error, drained = 0;
 
-       error = ds_get_bts_index(child->bts, &end);
-       if (error < 0)
-               return error;
+       trace = ds_read_bts(child->bts);
+       if (!trace)
+               return -EPERM;
+
+       if (!trace->read)
+               return -EOPNOTSUPP;
 
-       if (size < (end * sizeof(struct bts_struct)))
+       if (size < (trace->ds.top - trace->ds.begin))
                return -EIO;
 
-       error = ds_access_bts(child->bts, 0, (const void **)&raw);
-       if (error < 0)
-               return error;
+       for (at = trace->ds.begin; (void *)at < trace->ds.top;
+            out++, drained++, at += trace->ds.size) {
+               struct bts_struct bts;
+               int error;
 
-       for (i = 0; i < end; i++, out++, raw += bts_cfg.sizeof_bts) {
-               ptrace_bts_translate_record(&ret, raw);
+               error = trace->read(child->bts, at, &bts);
+               if (error < 0)
+                       return error;
 
-               if (copy_to_user(out, &ret, sizeof(ret)))
+               if (copy_to_user(out, &bts, sizeof(bts)))
                        return -EFAULT;
        }
 
-       error = ds_clear_bts(child->bts);
+       memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
+
+       error = ds_reset_bts(child->bts);
        if (error < 0)
                return error;
 
-       return end;
+       return drained;
+}
+
+static int ptrace_bts_allocate_buffer(struct task_struct *child, size_t size)
+{
+       child->bts_buffer = alloc_locked_buffer(size);
+       if (!child->bts_buffer)
+               return -ENOMEM;
+
+       child->bts_size = size;
+
+       return 0;
+}
+
+static void ptrace_bts_free_buffer(struct task_struct *child)
+{
+       free_locked_buffer(child->bts_buffer, child->bts_size);
+       child->bts_buffer = NULL;
+       child->bts_size = 0;
 }
 
 static int ptrace_bts_config(struct task_struct *child,
@@ -735,136 +668,86 @@ static int ptrace_bts_config(struct task_struct *child,
                             const struct ptrace_bts_config __user *ucfg)
 {
        struct ptrace_bts_config cfg;
-       int error = 0;
+       unsigned int flags = 0;
 
-       error = -EOPNOTSUPP;
-       if (!bts_cfg.sizeof_bts)
-               goto errout;
-
-       error = -EIO;
        if (cfg_size < sizeof(cfg))
-               goto errout;
+               return -EIO;
 
-       error = -EFAULT;
        if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
-               goto errout;
-
-       error = -EINVAL;
-       if ((cfg.flags & PTRACE_BTS_O_SIGNAL) &&
-           !(cfg.flags & PTRACE_BTS_O_ALLOC))
-               goto errout;
-
-       if (cfg.flags & PTRACE_BTS_O_ALLOC) {
-               bts_ovfl_callback_t ovfl = NULL;
-               unsigned int sig = 0;
-
-               error = -EINVAL;
-               if (cfg.size < (10 * bts_cfg.sizeof_bts))
-                       goto errout;
+               return -EFAULT;
 
-               if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
-                       if (!cfg.signal)
-                               goto errout;
+       if (child->bts) {
+               ds_release_bts(child->bts);
+               child->bts = NULL;
+       }
 
-                       error = -EOPNOTSUPP;
-                       goto errout;
+       if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
+               if (!cfg.signal)
+                       return -EINVAL;
 
-                       sig  = cfg.signal;
-               }
+               return -EOPNOTSUPP;
 
-               if (child->bts) {
-                       (void)ds_release_bts(child->bts);
-                       kfree(child->bts_buffer);
+               child->thread.bts_ovfl_signal = cfg.signal;
+       }
 
-                       child->bts = NULL;
-                       child->bts_buffer = NULL;
-               }
+       if ((cfg.flags & PTRACE_BTS_O_ALLOC) &&
+           (cfg.size != child->bts_size)) {
+               int error;
 
-               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;
-               }
+               ptrace_bts_free_buffer(child);
 
-               child->thread.bts_ovfl_signal = sig;
+               error = ptrace_bts_allocate_buffer(child, cfg.size);
+               if (error < 0)
+                       return error;
        }
 
-       error = -EINVAL;
-       if (!child->thread.ds_ctx && cfg.flags)
-               goto errout;
-
        if (cfg.flags & PTRACE_BTS_O_TRACE)
-               child->thread.debugctlmsr |= bts_cfg.debugctl_mask;
-       else
-               child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
+               flags |= BTS_USER;
 
        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);
+               flags |= BTS_TIMESTAMPS;
 
-       error = sizeof(cfg);
+       child->bts = ds_request_bts(child, child->bts_buffer, child->bts_size,
+                                   /* ovfl = */ NULL, /* th = */ (size_t)-1,
+                                   flags);
+       if (IS_ERR(child->bts)) {
+               int error = PTR_ERR(child->bts);
 
-out:
-       if (child->thread.debugctlmsr)
-               set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
-       else
-               clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
+               ptrace_bts_free_buffer(child);
+               child->bts = NULL;
 
-       return error;
+               return error;
+       }
 
-errout:
-       child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
-       clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
-       goto out;
+       return sizeof(cfg);
 }
 
 static int ptrace_bts_status(struct task_struct *child,
                             long cfg_size,
                             struct ptrace_bts_config __user *ucfg)
 {
+       const struct bts_trace *trace;
        struct ptrace_bts_config cfg;
-       size_t end;
-       const void *base, *max;
-       int error;
 
        if (cfg_size < sizeof(cfg))
                return -EIO;
 
-       error = ds_get_bts_end(child->bts, &end);
-       if (error < 0)
-               return error;
-
-       error = ds_access_bts(child->bts, /* index = */ 0, &base);
-       if (error < 0)
-               return error;
-
-       error = ds_access_bts(child->bts, /* index = */ end, &max);
-       if (error < 0)
-               return error;
+       trace = ds_read_bts(child->bts);
+       if (!trace)
+               return -EPERM;
 
        memset(&cfg, 0, sizeof(cfg));
-       cfg.size = (max - base);
+       cfg.size = trace->ds.end - trace->ds.begin;
        cfg.signal = child->thread.bts_ovfl_signal;
        cfg.bts_size = sizeof(struct bts_struct);
 
        if (cfg.signal)
                cfg.flags |= PTRACE_BTS_O_SIGNAL;
 
-       if (test_tsk_thread_flag(child, TIF_DEBUGCTLMSR) &&
-           child->thread.debugctlmsr & bts_cfg.debugctl_mask)
+       if (trace->ds.flags & BTS_USER)
                cfg.flags |= PTRACE_BTS_O_TRACE;
 
-       if (test_tsk_thread_flag(child, TIF_BTS_TRACE_TS))
+       if (trace->ds.flags & BTS_TIMESTAMPS)
                cfg.flags |= PTRACE_BTS_O_SCHED;
 
        if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
@@ -873,106 +756,77 @@ static int ptrace_bts_status(struct task_struct *child,
        return sizeof(cfg);
 }
 
-static int ptrace_bts_write_record(struct task_struct *child,
-                                  const struct bts_struct *in)
+static int ptrace_bts_clear(struct task_struct *child)
 {
-       unsigned char bts_record[BTS_MAX_RECORD_SIZE];
+       const struct bts_trace *trace;
 
-       BUG_ON(BTS_MAX_RECORD_SIZE < bts_cfg.sizeof_bts);
+       trace = ds_read_bts(child->bts);
+       if (!trace)
+               return -EPERM;
 
-       memset(bts_record, 0, bts_cfg.sizeof_bts);
-       switch (in->qualifier) {
-       case BTS_INVALID:
-               break;
+       memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
 
-       case BTS_BRANCH:
-               bts_set(bts_record, bts_from, in->variant.lbr.from_ip);
-               bts_set(bts_record, bts_to,   in->variant.lbr.to_ip);
-               break;
+       return ds_reset_bts(child->bts);
+}
 
-       case BTS_TASK_ARRIVES:
-       case BTS_TASK_DEPARTS:
-               bts_set(bts_record, bts_from,    bts_escape);
-               bts_set(bts_record, bts_qual,    in->qualifier);
-               bts_set(bts_record, bts_jiffies, in->variant.jiffies);
-               break;
+static int ptrace_bts_size(struct task_struct *child)
+{
+       const struct bts_trace *trace;
 
-       default:
-               return -EINVAL;
-       }
+       trace = ds_read_bts(child->bts);
+       if (!trace)
+               return -EPERM;
 
-       return ds_write_bts(child->bts, bts_record, bts_cfg.sizeof_bts);
+       return (trace->ds.top - trace->ds.begin) / trace->ds.size;
 }
 
-void ptrace_bts_take_timestamp(struct task_struct *tsk,
-                              enum bts_qualifier qualifier)
+static void ptrace_bts_fork(struct task_struct *tsk)
 {
-       struct bts_struct rec = {
-               .qualifier = qualifier,
-               .variant.jiffies = jiffies_64
-       };
-
-       ptrace_bts_write_record(tsk, &rec);
+       tsk->bts = NULL;
+       tsk->bts_buffer = NULL;
+       tsk->bts_size = 0;
+       tsk->thread.bts_ovfl_signal = 0;
 }
 
-static const struct bts_configuration bts_cfg_netburst = {
-       .sizeof_bts    = sizeof(long) * 3,
-       .sizeof_field  = sizeof(long),
-       .debugctl_mask = (1<<2)|(1<<3)|(1<<5)
-};
+static void ptrace_bts_untrace(struct task_struct *child)
+{
+       if (unlikely(child->bts)) {
+               ds_release_bts(child->bts);
+               child->bts = NULL;
 
-static const struct bts_configuration bts_cfg_pentium_m = {
-       .sizeof_bts    = sizeof(long) * 3,
-       .sizeof_field  = sizeof(long),
-       .debugctl_mask = (1<<6)|(1<<7)
-};
+               /* We cannot update total_vm and locked_vm since
+                  child's mm is already gone. But we can reclaim the
+                  memory. */
+               kfree(child->bts_buffer);
+               child->bts_buffer = NULL;
+               child->bts_size = 0;
+       }
+}
 
-static const struct bts_configuration bts_cfg_core2 = {
-       .sizeof_bts    = 8 * 3,
-       .sizeof_field  = 8,
-       .debugctl_mask = (1<<6)|(1<<7)|(1<<9)
-};
+static void ptrace_bts_detach(struct task_struct *child)
+{
+       if (unlikely(child->bts)) {
+               ds_release_bts(child->bts);
+               child->bts = NULL;
+
+               ptrace_bts_free_buffer(child);
+       }
+}
+#else
+static inline void ptrace_bts_fork(struct task_struct *tsk) {}
+static inline void ptrace_bts_detach(struct task_struct *child) {}
+static inline void ptrace_bts_untrace(struct task_struct *child) {}
+#endif /* CONFIG_X86_PTRACE_BTS */
 
-static inline void bts_configure(const struct bts_configuration *cfg)
+void x86_ptrace_fork(struct task_struct *child, unsigned long clone_flags)
 {
-       bts_cfg = *cfg;
+       ptrace_bts_fork(child);
 }
 
-void __cpuinit ptrace_bts_init_intel(struct cpuinfo_x86 *c)
+void x86_ptrace_untrace(struct task_struct *child)
 {
-       switch (c->x86) {
-       case 0x6:
-               switch (c->x86_model) {
-               case 0 ... 0xC:
-                       /* sorry, don't know about them */
-                       break;
-               case 0xD:
-               case 0xE: /* Pentium M */
-                       bts_configure(&bts_cfg_pentium_m);
-                       break;
-               default: /* Core2, Atom, ... */
-                       bts_configure(&bts_cfg_core2);
-                       break;
-               }
-               break;
-       case 0xF:
-               switch (c->x86_model) {
-               case 0x0:
-               case 0x1:
-               case 0x2: /* Netburst */
-                       bts_configure(&bts_cfg_netburst);
-                       break;
-               default:
-                       /* sorry, don't know about them */
-                       break;
-               }
-               break;
-       default:
-               /* sorry, don't know about them */
-               break;
-       }
+       ptrace_bts_untrace(child);
 }
-#endif /* CONFIG_X86_PTRACE_BTS */
 
 /*
  * Called by kernel/ptrace.c when detaching..
@@ -985,19 +839,7 @@ void ptrace_disable(struct task_struct *child)
 #ifdef TIF_SYSCALL_EMU
        clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 #endif
-#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)
-                       clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
-
-               clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
-       }
-#endif /* CONFIG_X86_PTRACE_BTS */
+       ptrace_bts_detach(child);
 }
 
 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
@@ -1128,16 +970,9 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                        (child, data, (struct ptrace_bts_config __user *)addr);
                break;
 
-       case PTRACE_BTS_SIZE: {
-               size_t size;
-
-               ret = ds_get_bts_index(child->bts, &size);
-               if (ret == 0) {
-                       BUG_ON(size != (int) size);
-                       ret = (int) size;
-               }
+       case PTRACE_BTS_SIZE:
+               ret = ptrace_bts_size(child);
                break;
-       }
 
        case PTRACE_BTS_GET:
                ret = ptrace_bts_read_record
@@ -1145,7 +980,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                break;
 
        case PTRACE_BTS_CLEAR:
-               ret = ds_clear_bts(child->bts);
+               ret = ptrace_bts_clear(child);
                break;
 
        case PTRACE_BTS_DRAIN:
@@ -1408,6 +1243,14 @@ 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: