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-rw-r--r--include/linux/ring_buffer.h3
-rw-r--r--kernel/trace/ring_buffer.c31
-rw-r--r--kernel/trace/trace.c30
-rw-r--r--kernel/trace/trace.h9
4 files changed, 39 insertions, 34 deletions
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 17fbb7855295..8de035f4f0d9 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -94,8 +94,7 @@ struct trace_buffer *__ring_buffer_alloc_range(unsigned long size, unsigned flag
unsigned long range_size,
struct lock_class_key *key);
-bool ring_buffer_last_boot_delta(struct trace_buffer *buffer, long *text,
- long *data);
+bool ring_buffer_last_boot_delta(struct trace_buffer *buffer, unsigned long *kaslr_addr);
/*
* Because the ring buffer is generic, if other users of the ring buffer get
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 510409f97992..9aa2e818eced 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -31,6 +31,7 @@
#include <asm/local64.h>
#include <asm/local.h>
+#include <asm/setup.h>
#include "trace.h"
@@ -49,8 +50,7 @@ static void update_pages_handler(struct work_struct *work);
struct ring_buffer_meta {
int magic;
int struct_size;
- unsigned long text_addr;
- unsigned long data_addr;
+ unsigned long kaslr_addr;
unsigned long first_buffer;
unsigned long head_buffer;
unsigned long commit_buffer;
@@ -550,8 +550,7 @@ struct trace_buffer {
unsigned long range_addr_start;
unsigned long range_addr_end;
- long last_text_delta;
- long last_data_delta;
+ unsigned long kaslr_addr;
unsigned int subbuf_size;
unsigned int subbuf_order;
@@ -1891,16 +1890,13 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer)
}
}
-/* Used to calculate data delta */
-static char rb_data_ptr[] = "";
-
-#define THIS_TEXT_PTR ((unsigned long)rb_meta_init_text_addr)
-#define THIS_DATA_PTR ((unsigned long)rb_data_ptr)
-
static void rb_meta_init_text_addr(struct ring_buffer_meta *meta)
{
- meta->text_addr = THIS_TEXT_PTR;
- meta->data_addr = THIS_DATA_PTR;
+#ifdef CONFIG_RANDOMIZE_BASE
+ meta->kaslr_addr = kaslr_offset();
+#else
+ meta->kaslr_addr = 0;
+#endif
}
static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages)
@@ -1928,8 +1924,7 @@ static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages)
meta->first_buffer += delta;
meta->head_buffer += delta;
meta->commit_buffer += delta;
- buffer->last_text_delta = THIS_TEXT_PTR - meta->text_addr;
- buffer->last_data_delta = THIS_DATA_PTR - meta->data_addr;
+ buffer->kaslr_addr = meta->kaslr_addr;
continue;
}
@@ -2482,17 +2477,15 @@ struct trace_buffer *__ring_buffer_alloc_range(unsigned long size, unsigned flag
*
* Returns: The true if the delta is non zero
*/
-bool ring_buffer_last_boot_delta(struct trace_buffer *buffer, long *text,
- long *data)
+bool ring_buffer_last_boot_delta(struct trace_buffer *buffer, unsigned long *kaslr_addr)
{
if (!buffer)
return false;
- if (!buffer->last_text_delta)
+ if (!buffer->kaslr_addr)
return false;
- *text = buffer->last_text_delta;
- *data = buffer->last_data_delta;
+ *kaslr_addr = buffer->kaslr_addr;
return true;
}
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0e6d517e74e0..934658cda570 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -50,7 +50,7 @@
#include <linux/irq_work.h>
#include <linux/workqueue.h>
-#include <asm/setup.h> /* COMMAND_LINE_SIZE */
+#include <asm/setup.h> /* COMMAND_LINE_SIZE and kaslr_offset() */
#include "trace.h"
#include "trace_output.h"
@@ -4193,7 +4193,7 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
* safe to use if the array has delta offsets
* Force printing via the fields.
*/
- if ((tr->text_delta || tr->data_delta) &&
+ if ((tr->text_delta) &&
event->type > __TRACE_LAST_TYPE)
return print_event_fields(iter, event);
@@ -5990,7 +5990,7 @@ ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
static void update_last_data(struct trace_array *tr)
{
- if (!tr->text_delta && !tr->data_delta)
+ if (!(tr->flags & TRACE_ARRAY_FL_LAST_BOOT))
return;
/*
@@ -6003,7 +6003,8 @@ static void update_last_data(struct trace_array *tr)
/* Using current data now */
tr->text_delta = 0;
- tr->data_delta = 0;
+
+ tr->flags &= ~TRACE_ARRAY_FL_LAST_BOOT;
}
/**
@@ -6821,8 +6822,17 @@ tracing_last_boot_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t
seq_buf_init(&seq, buf, 64);
- seq_buf_printf(&seq, "text delta:\t%ld\n", tr->text_delta);
- seq_buf_printf(&seq, "data delta:\t%ld\n", tr->data_delta);
+ /*
+ * Do not leak KASLR address. This only shows the KASLR address of
+ * the last boot. When the ring buffer is started, the LAST_BOOT
+ * flag gets cleared, and this should only report "current".
+ * Otherwise it shows the KASLR address from the previous boot which
+ * should not be the same as the current boot.
+ */
+ if (tr->flags & TRACE_ARRAY_FL_LAST_BOOT)
+ seq_buf_printf(&seq, "%lx\t[kernel]\n", tr->kaslr_addr);
+ else
+ seq_buf_puts(&seq, "# Current\n");
return simple_read_from_buffer(ubuf, cnt, ppos, buf, seq_buf_used(&seq));
}
@@ -9210,8 +9220,10 @@ allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size
tr->range_addr_start,
tr->range_addr_size);
- ring_buffer_last_boot_delta(buf->buffer,
- &tr->text_delta, &tr->data_delta);
+#ifdef CONFIG_RANDOMIZE_BASE
+ if (ring_buffer_last_boot_delta(buf->buffer, &tr->kaslr_addr))
+ tr->text_delta = kaslr_offset() - tr->kaslr_addr;
+#endif
/*
* This is basically the same as a mapped buffer,
* with the same restrictions.
@@ -10459,7 +10471,7 @@ __init static void enable_instances(void)
* to it.
*/
if (start) {
- tr->flags |= TRACE_ARRAY_FL_BOOT;
+ tr->flags |= TRACE_ARRAY_FL_BOOT | TRACE_ARRAY_FL_LAST_BOOT;
tr->ref++;
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 9c21ba45b7af..abe8169c3e87 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -348,8 +348,8 @@ struct trace_array {
unsigned int mapped;
unsigned long range_addr_start;
unsigned long range_addr_size;
+ unsigned long kaslr_addr;
long text_delta;
- long data_delta;
struct trace_pid_list __rcu *filtered_pids;
struct trace_pid_list __rcu *filtered_no_pids;
@@ -433,9 +433,10 @@ struct trace_array {
};
enum {
- TRACE_ARRAY_FL_GLOBAL = BIT(0),
- TRACE_ARRAY_FL_BOOT = BIT(1),
- TRACE_ARRAY_FL_MOD_INIT = BIT(2),
+ TRACE_ARRAY_FL_GLOBAL = BIT(0),
+ TRACE_ARRAY_FL_BOOT = BIT(1),
+ TRACE_ARRAY_FL_LAST_BOOT = BIT(2),
+ TRACE_ARRAY_FL_MOD_INIT = BIT(3),
};
#ifdef CONFIG_MODULES
generated by cgit v1.2.3 (git 2.46.0) at 2025-07-31 13:47:40 +0000