x86, ptrace: support 32bit-cross-64bit BTS recording

Support BTS recording of 32bit and 64bit tasks from 32bit or 64bit tasks.

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>

2 files changed, 46 insertions, 47 deletions

diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index 6eb5d49a36bb..1c5ca4d18787 100644
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@ -111,53 +111,53 @@ static struct ds_configuration ds_cfg;
  * Accessor functions for some DS and BTS fields using the above
  * global ptrace_bts_cfg.
  */
-static inline void *get_bts_buffer_base(char *base)
+static inline unsigned long get_bts_buffer_base(char *base)
 {
-        return *(void **)(base + ds_cfg.bts_buffer_base.offset);
+        return *(unsigned long *)(base + ds_cfg.bts_buffer_base.offset);
 }
-static inline void set_bts_buffer_base(char *base, void *value)
+static inline void set_bts_buffer_base(char *base, unsigned long value)
 {
-        (*(void **)(base + ds_cfg.bts_buffer_base.offset)) = value;
+        (*(unsigned long *)(base + ds_cfg.bts_buffer_base.offset)) = value;
 }
-static inline void *get_bts_index(char *base)
+static inline unsigned long get_bts_index(char *base)
 {
-        return *(void **)(base + ds_cfg.bts_index.offset);
+        return *(unsigned long *)(base + ds_cfg.bts_index.offset);
 }
-static inline void set_bts_index(char *base, void *value)
+static inline void set_bts_index(char *base, unsigned long value)
 {
-        (*(void **)(base + ds_cfg.bts_index.offset)) = value;
+        (*(unsigned long *)(base + ds_cfg.bts_index.offset)) = value;
 }
-static inline void *get_bts_absolute_maximum(char *base)
+static inline unsigned long get_bts_absolute_maximum(char *base)
 {
-        return *(void **)(base + ds_cfg.bts_absolute_maximum.offset);
+        return *(unsigned long *)(base + ds_cfg.bts_absolute_maximum.offset);
 }
-static inline void set_bts_absolute_maximum(char *base, void *value)
+static inline void set_bts_absolute_maximum(char *base, unsigned long value)
 {
-        (*(void **)(base + ds_cfg.bts_absolute_maximum.offset)) = value;
+        (*(unsigned long *)(base + ds_cfg.bts_absolute_maximum.offset)) = value;
 }
-static inline void *get_bts_interrupt_threshold(char *base)
+static inline unsigned long get_bts_interrupt_threshold(char *base)
 {
-        return *(void **)(base + ds_cfg.bts_interrupt_threshold.offset);
+        return *(unsigned long *)(base + ds_cfg.bts_interrupt_threshold.offset);
 }
-static inline void set_bts_interrupt_threshold(char *base, void *value)
+static inline void set_bts_interrupt_threshold(char *base, unsigned long value)
 {
-        (*(void **)(base + ds_cfg.bts_interrupt_threshold.offset)) = value;
+        (*(unsigned long *)(base + ds_cfg.bts_interrupt_threshold.offset)) = value;
 }
-static inline long get_from_ip(char *base)
+static inline unsigned long get_from_ip(char *base)
 {
-        return *(long *)(base + ds_cfg.from_ip.offset);
+        return *(unsigned long *)(base + ds_cfg.from_ip.offset);
 }
-static inline void set_from_ip(char *base, long value)
+static inline void set_from_ip(char *base, unsigned long value)
 {
-        (*(long *)(base + ds_cfg.from_ip.offset)) = value;
+        (*(unsigned long *)(base + ds_cfg.from_ip.offset)) = value;
 }
-static inline long get_to_ip(char *base)
+static inline unsigned long get_to_ip(char *base)
 {
-        return *(long *)(base + ds_cfg.to_ip.offset);
+        return *(unsigned long *)(base + ds_cfg.to_ip.offset);
 }
-static inline void set_to_ip(char *base, long value)
+static inline void set_to_ip(char *base, unsigned long value)
 {
-        (*(long *)(base + ds_cfg.to_ip.offset)) = value;
+        (*(unsigned long *)(base + ds_cfg.to_ip.offset)) = value;
 }
 static inline unsigned char get_info_type(char *base)
 {
@@ -180,7 +180,7 @@ static inline void set_info_data(char *base, unsigned long value)
 int ds_allocate(void **dsp, size_t bts_size_in_bytes)
 {
         size_t bts_size_in_records;
-        void *bts;
+        unsigned long bts;
         void *ds;
 
         if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
@@ -197,7 +197,7 @@ int ds_allocate(void **dsp, size_t bts_size_in_bytes)
         if (bts_size_in_bytes <= 0)
                 return -EINVAL;
 
-        bts = kzalloc(bts_size_in_bytes, GFP_KERNEL);
+        bts = (unsigned long)kzalloc(bts_size_in_bytes, GFP_KERNEL);
 
         if (!bts)
                 return -ENOMEM;
@@ -205,7 +205,7 @@ int ds_allocate(void **dsp, size_t bts_size_in_bytes)
         ds = kzalloc(ds_cfg.sizeof_ds, GFP_KERNEL);
 
         if (!ds) {
-                kfree(bts);
+                kfree((void *)bts);
                 return -ENOMEM;
         }
 
@@ -221,7 +221,7 @@ int ds_allocate(void **dsp, size_t bts_size_in_bytes)
 int ds_free(void **dsp)
 {
         if (*dsp)
-                kfree(get_bts_buffer_base(*dsp));
+                kfree((void *)get_bts_buffer_base(*dsp));
         kfree(*dsp);
         *dsp = 0;
 
@@ -230,7 +230,7 @@ int ds_free(void **dsp)
 
 int ds_get_bts_size(void *ds)
 {
-        size_t size_in_bytes;
+        int size_in_bytes;
 
         if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
                 return -EOPNOTSUPP;
@@ -246,7 +246,7 @@ int ds_get_bts_size(void *ds)
 
 int ds_get_bts_end(void *ds)
 {
-        size_t size_in_bytes = ds_get_bts_size(ds);
+        int size_in_bytes = ds_get_bts_size(ds);
 
         if (size_in_bytes <= 0)
                 return size_in_bytes;
@@ -256,7 +256,7 @@ int ds_get_bts_end(void *ds)
 
 int ds_get_bts_index(void *ds)
 {
-        size_t index_offset_in_bytes;
+        int index_offset_in_bytes;
 
         if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
                 return -EOPNOTSUPP;
@@ -288,19 +288,19 @@ int ds_get_overflow(void *ds)
 int ds_clear(void *ds)
 {
         int bts_size = ds_get_bts_size(ds);
-        void *bts_base;
+        unsigned long bts_base;
 
         if (bts_size <= 0)
                 return bts_size;
 
         bts_base = get_bts_buffer_base(ds);
-        memset(bts_base, 0, bts_size);
+        memset((void *)bts_base, 0, bts_size);
 
         set_bts_index(ds, bts_base);
         return 0;
 }
 
-int ds_read_bts(void *ds, size_t index, struct bts_struct *out)
+int ds_read_bts(void *ds, int index, struct bts_struct *out)
 {
         void *bts;
 
@@ -313,8 +313,7 @@ int ds_read_bts(void *ds, size_t index, struct bts_struct *out)
         if (index >= ds_get_bts_size(ds))
                 return -EINVAL;
 
-        bts = get_bts_buffer_base(ds);
-        bts = (char *)bts + (index * ds_cfg.sizeof_bts);
+        bts = (void *)(get_bts_buffer_base(ds) + (index * ds_cfg.sizeof_bts));
 
         memset(out, 0, sizeof(*out));
         if (get_from_ip(bts) == BTS_ESCAPE_ADDRESS) {
@@ -326,12 +325,12 @@ int ds_read_bts(void *ds, size_t index, struct bts_struct *out)
                 out->variant.lbr.to_ip   = get_to_ip(bts);
         }
 
-        return 0;
+        return sizeof(*out);;
 }
 
 int ds_write_bts(void *ds, const struct bts_struct *in)
 {
-        void *bts;
+        unsigned long bts;
 
         if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
                 return -EOPNOTSUPP;
@@ -341,33 +340,33 @@ int ds_write_bts(void *ds, const struct bts_struct *in)
 
         bts = get_bts_index(ds);
 
-        memset(bts, 0, ds_cfg.sizeof_bts);
+        memset((void *)bts, 0, ds_cfg.sizeof_bts);
         switch (in->qualifier) {
         case BTS_INVALID:
                 break;
 
         case BTS_BRANCH:
-                set_from_ip(bts, in->variant.lbr.from_ip);
-                set_to_ip(bts, in->variant.lbr.to_ip);
+                set_from_ip((void *)bts, in->variant.lbr.from_ip);
+                set_to_ip((void *)bts, in->variant.lbr.to_ip);
                 break;
 
         case BTS_TASK_ARRIVES:
         case BTS_TASK_DEPARTS:
-                set_from_ip(bts, BTS_ESCAPE_ADDRESS);
-                set_info_type(bts, in->qualifier);
-                set_info_data(bts, in->variant.jiffies);
+                set_from_ip((void *)bts, BTS_ESCAPE_ADDRESS);
+                set_info_type((void *)bts, in->qualifier);
+                set_info_data((void *)bts, in->variant.jiffies);
                 break;
 
         default:
                 return -EINVAL;
         }
 
-        bts = (char *)bts + ds_cfg.sizeof_bts;
+        bts = bts + ds_cfg.sizeof_bts;
         if (bts >= get_bts_absolute_maximum(ds))
                 bts = get_bts_buffer_base(ds);
         set_bts_index(ds, bts);
 
-        return 0;
+        return ds_cfg.sizeof_bts;
 }
 
 unsigned long ds_debugctl_mask(void)
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 88ed1e74cee9..236528bec6eb 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -558,7 +558,7 @@ static int ptrace_bts_read_record(struct task_struct *child,
 
         retval = ds_read_bts((void *)child->thread.ds_area_msr,
                              bts_index, &ret);
-        if (retval)
+        if (retval < 0)
                 return retval;
 
         if (copy_to_user(out, &ret, sizeof(ret)))