From: Joel Granados <j.granados@xxxxxxxxxxx> Added a new check named check_sentinel_ctltable that prints a warning when a sentinel element is detected in a ctl_table struct array. Sentinels marking the end of a ctl_table array where completely removed from the linux kernel in [1]. We add this warning to avoid cases where a sentinel gets added by mistake. [1] https://lore.kernel.org/20240604-jag-sysctl_remset-v1-0-2df7ecdba0bd@xxxxxxxxxxx Signed-off-by: Joel Granados <j.granados@xxxxxxxxxxx> --- Signed-off-by: Joel Granados <j.granados@xxxxxxxxxxx> -- --- check_list.h | 1 + check_sentinel_ctltable.c | 41 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+) diff --git a/check_list.h b/check_list.h index 7115b069..a870c95f 100644 --- a/check_list.h +++ b/check_list.h @@ -252,6 +252,7 @@ CK(check_direct_return_instead_of_goto) CK(check_double_fget) CK(check_negative_error_code_type_promoted) CK(check_uninitialized_kobj) +CK(check_sentinel_ctltable) /* wine specific stuff */ CK(check_wine_filehandles) diff --git a/check_sentinel_ctltable.c b/check_sentinel_ctltable.c new file mode 100644 index 00000000..8bdb582a --- /dev/null +++ b/check_sentinel_ctltable.c @@ -0,0 +1,41 @@ +#include "smatch.h" + +struct non_null_ctltable_elems { + const char *name; + const int len; +}; + +static struct non_null_ctltable_elems non_null_elems[] = { + {.name = "->procname", .len = 10}, + {.name = "->proc_handler", .len = 14}, +}; + +static int match_ctl_table_array_sentinel(struct expression *expr) +{ + char * member_name = NULL; + if (!expr) + return 0; + + member_name = get_member_name(expr); + if (!member_name) + return 0; + + if (strncmp(member_name, "(struct ctl_table)", 18) != 0) + return 0; + + for (int i = 0 ; i < ARRAY_SIZE(non_null_elems) ; ++i) { + if (strncmp(member_name + 18, non_null_elems[i].name, non_null_elems[i].len) ==0) { + sm_warning ("(struct ctl_table)%s cannot be NULL. Expression : %s", + non_null_elems[i].name, expr_to_str(expr)); + return 0; + } + } + + return 0; +} + +void check_sentinel_ctltable(int id) +{ + add_hook(&match_ctl_table_array_sentinel, EXPR_HOOK); +} + --- base-commit: ff1cc4d453ffeddf3cf3dc031c5b129eefbf3e2c change-id: 20240614-master-db259d890db0 Best regards, -- Joel Granados <j.granados@xxxxxxxxxxx>
