tracing: Fix compilation warning on arm32

JIRA: https://issues.redhat.com/browse/RHEL-115358

commit 2fbdb6d
Author: Pan Taixi <[email protected]>
Date:   Mon May 26 09:37:31 2025 +0800

    tracing: Fix compilation warning on arm32

    On arm32, size_t is defined to be unsigned int, while PAGE_SIZE is
    unsigned long. This hence triggers a compilation warning as min()
    asserts the type of two operands to be equal. Casting PAGE_SIZE to size_t
    solves this issue and works on other target architectures as well.

    Compilation warning details:

    kernel/trace/trace.c: In function 'tracing_splice_read_pipe':
    ./include/linux/minmax.h:20:28: warning: comparison of distinct pointer types lacks a cast
      (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
                                ^
    ./include/linux/minmax.h:26:4: note: in expansion of macro '__typecheck'
       (__typecheck(x, y) && __no_side_effects(x, y))
        ^~~~~~~~~~~

    ...

    kernel/trace/trace.c:6771:8: note: in expansion of macro 'min'
            min((size_t)trace_seq_used(&iter->seq),
            ^~~

    Cc: [email protected]
    Link: https://lore.kernel.org/[email protected]
    Fixes: f5178c4 ("tracing: Fix oob write in trace_seq_to_buffer()")
    Reviewed-by: Jeongjun Park <[email protected]>
    Signed-off-by: Pan Taixi <[email protected]>
    Signed-off-by: Steven Rostedt (Google) <[email protected]>

Signed-off-by: Jerome Marchand <[email protected]>

Author: jeromemarchand

kernel/trace/trace.c

@@ -6702,7 +6702,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
 		ret = trace_seq_to_buffer(&iter->seq,
 					  page_address(spd.pages[i]),
 					  min((size_t)trace_seq_used(&iter->seq),
-						  PAGE_SIZE));
+						  (size_t)PAGE_SIZE));
 		if (ret < 0) {
 			__free_page(spd.pages[i]);
 			break;