tracing: Adjust addresses for printing out fields

Add adjustments to the values of the "fields" output if the buffer is a
persistent ring buffer to adjust the addresses to both the kernel core and
kernel modules if they match a module in the persistent memory and that
module is also loaded.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250325185619.54b85587@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 73037efdb45fc34c23088a60e8cf6dcb6889cad6..e7ebad1776796747d935506117c2abbd6162610b 100644 (file)
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -938,6 +938,9 @@ static void print_fields(struct trace_iterator *iter, struct trace_event_call *c
                         struct list_head *head)
 {
        struct ftrace_event_field *field;
+       struct trace_array *tr = iter->tr;
+       unsigned long long laddr;
+       unsigned long addr;
        int offset;
        int len;
        int ret;
@@ -974,8 +977,8 @@ static void print_fields(struct trace_iterator *iter, struct trace_event_call *c
                case FILTER_PTR_STRING:
                        if (!iter->fmt_size)
                                trace_iter_expand_format(iter);
-                       pos = *(void **)pos;
-                       ret = strncpy_from_kernel_nofault(iter->fmt, pos,
+                       addr = trace_adjust_address(tr, *(unsigned long *)pos);
+                       ret = strncpy_from_kernel_nofault(iter->fmt, (void *)addr,
                                                          iter->fmt_size);
                        if (ret < 0)
                                trace_seq_printf(&iter->seq, "(0x%px)", pos);
@@ -984,8 +987,8 @@ static void print_fields(struct trace_iterator *iter, struct trace_event_call *c
                                                 pos, iter->fmt);
                        break;
                case FILTER_TRACE_FN:
-                       pos = *(void **)pos;
-                       trace_seq_printf(&iter->seq, "%pS", pos);
+                       addr = trace_adjust_address(tr, *(unsigned long *)pos);
+                       trace_seq_printf(&iter->seq, "%pS", (void *)addr);
                        break;
                case FILTER_CPU:
                case FILTER_OTHER:
@@ -1015,24 +1018,25 @@ static void print_fields(struct trace_iterator *iter, struct trace_event_call *c
                                        break;
                                }
 
-                               if (sizeof(long) == 4)
+                               addr = *(unsigned int *)pos;
+                               if (sizeof(long) == 4) {
+                                       addr = trace_adjust_address(tr, addr);
                                        trace_seq_printf(&iter->seq, "%pS (%d)",
-                                                        *(void **)pos,
-                                                        *(unsigned int *)pos);
-                               else
+                                                        (void *)addr, (int)addr);
+                               } else {
                                        trace_seq_printf(&iter->seq, "0x%x (%d)",
-                                                        *(unsigned int *)pos,
-                                                        *(unsigned int *)pos);
+                                                        (unsigned int)addr, (int)addr);
+                               }
                                break;
                        case 8:
-                               if (sizeof(long) == 8)
+                               laddr = *(unsigned long long *)pos;
+                               if (sizeof(long) == 8) {
+                                       laddr = trace_adjust_address(tr, (unsigned long)laddr);
                                        trace_seq_printf(&iter->seq, "%pS (%lld)",
-                                                        *(void **)pos,
-                                                        *(unsigned long long *)pos);
-                               else
-                                       trace_seq_printf(&iter->seq, "0x%llx (%lld)",
-                                                        *(unsigned long long *)pos,
-                                                        *(unsigned long long *)pos);
+                                                        (void *)(long)laddr, laddr);
+                               } else {
+                                       trace_seq_printf(&iter->seq, "0x%llx (%lld)", laddr, laddr);
+                               }
                                break;
                        default:
                                trace_seq_puts(&iter->seq, "<INVALID-SIZE>");