lkml.org 
[lkml]   [2021]   [Nov]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.15 100/279] tracing/histogram: Do not copy the fixed-size char array field over the field size
    Date
    From: Masami Hiramatsu <mhiramat@kernel.org>

    [ Upstream commit 63f84ae6b82bb4dff672f76f30c6fd7b9d3766bc ]

    Do not copy the fixed-size char array field of the events over
    the field size. The histogram treats char array as a string and
    there are 2 types of char array in the event, fixed-size and
    dynamic string. The dynamic string (__data_loc) field must be
    null terminated, but the fixed-size char array field may not
    be null terminated (not a string, but just a data).
    In that case, histogram can copy the data after the field.
    This uses the original field size for fixed-size char array
    field to restrict the histogram not to access over the original
    field size.

    Link: https://lkml.kernel.org/r/163673292822.195747.3696966210526410250.stgit@devnote2

    Fixes: 02205a6752f2 (tracing: Add support for 'field variables')
    Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
    Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    kernel/trace/trace_events_hist.c | 9 +++++----
    1 file changed, 5 insertions(+), 4 deletions(-)

    diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
    index f01e442716e2f..de37664ef0476 100644
    --- a/kernel/trace/trace_events_hist.c
    +++ b/kernel/trace/trace_events_hist.c
    @@ -1733,9 +1733,10 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
    if (!hist_field->type)
    goto free;

    - if (field->filter_type == FILTER_STATIC_STRING)
    + if (field->filter_type == FILTER_STATIC_STRING) {
    hist_field->fn = hist_field_string;
    - else if (field->filter_type == FILTER_DYN_STRING)
    + hist_field->size = field->size;
    + } else if (field->filter_type == FILTER_DYN_STRING)
    hist_field->fn = hist_field_dynstring;
    else
    hist_field->fn = hist_field_pstring;
    @@ -2691,7 +2692,7 @@ static inline void __update_field_vars(struct tracing_map_elt *elt,
    char *str = elt_data->field_var_str[j++];
    char *val_str = (char *)(uintptr_t)var_val;

    - strscpy(str, val_str, STR_VAR_LEN_MAX);
    + strscpy(str, val_str, val->size);
    var_val = (u64)(uintptr_t)str;
    }
    tracing_map_set_var(elt, var_idx, var_val);
    @@ -4586,7 +4587,7 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,

    str = elt_data->field_var_str[idx];
    val_str = (char *)(uintptr_t)hist_val;
    - strscpy(str, val_str, STR_VAR_LEN_MAX);
    + strscpy(str, val_str, hist_field->size);

    hist_val = (u64)(uintptr_t)str;
    }
    --
    2.33.0


    \
     
     \ /
      Last update: 2021-11-24 14:52    [W:4.255 / U:0.532 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site