perf auxtrace: Fix address filter entire kernel size

kallsyms is not completely in address order.

In find_entire_kern_cb(), calculate the kernel end from the maximum
address not the last symbol.

Example:

 Before:

    $ sudo cat /proc/kallsyms | grep ' [twTw] ' | tail -1
    ffffffffc00b8bd0 t bpf_prog_6deef7357e7b4530    [bpf]
    $ sudo cat /proc/kallsyms | grep ' [twTw] ' | sort | tail -1
    ffffffffc15e0cc0 t iwl_mvm_exit [iwlmvm]
    $ perf.d093603a05aa record -v --kcore -e intel_pt// --filter 'filter *' -- uname |& grep filter
    Address filter: filter 0xffffffff93200000/0x2ceba000

 After:

    $ perf.8fb0f7a01f8e record -v --kcore -e intel_pt// --filter 'filter *' -- uname |& grep filter
    Address filter: filter 0xffffffff93200000/0x2e3e2000

Fixes: 1b36c03e356936d6 ("perf record: Add support for using symbols in address filters")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230403154831.8651-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index 498ff7f24463bc636e0184c9b293b1d4d7e6732b..b2a5e5397badfedc51a400f5703986c64b8f8781 100644 (file)
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -2449,6 +2449,7 @@ static int find_entire_kern_cb(void *arg, const char *name __maybe_unused,
                               char type, u64 start)
 {
        struct sym_args *args = arg;
+       u64 size;
 
        if (!kallsyms__is_function(type))
                return 0;
@@ -2458,7 +2459,9 @@ static int find_entire_kern_cb(void *arg, const char *name __maybe_unused,
                args->start = start;
        }
        /* Don't know exactly where the kernel ends, so we add a page */
-       args->size = round_up(start, page_size) + page_size - args->start;
+       size = round_up(start, page_size) + page_size - args->start;
+       if (size > args->size)
+               args->size = size;
 
        return 0;
 }