Re: [PATCH 2/2] module: Show the last unloaded module's taint flag(s)
From: Christophe Leroy <hidden>
Date: 2022-06-28 05:54:36
Also in:
lkml
Le 27/06/2022 à 18:40, Aaron Tomlin a écrit :
quoted hunk ↗ jump to hunk
For diagnostic purposes, this patch, in addition to keeping a record/or track of the last known unloaded module, we now will include the module's taint flag(s) too e.g: " [last unloaded: fpga_mgr_mod(OE)]" Signed-off-by: Aaron Tomlin <redacted> --- kernel/module/main.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)diff --git a/kernel/module/main.c b/kernel/module/main.c index dcb83cf18d84..0ca6fd38b903 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c@@ -524,7 +524,12 @@ static struct module_attribute modinfo_##field = { \ MODINFO_ATTR(version); MODINFO_ATTR(srcversion); -static char last_unloaded_module[MODULE_NAME_LEN+1]; +/* + * Maximum number of characters written by module_flags() + * without a module's state information. + */ +#define LAST_UNLOADED_MODULE_NAME_LEN (MODULE_NAME_LEN + MODULE_FLAGS_BUF_SIZE - 2 + 1) +static char last_unloaded_module[LAST_UNLOADED_MODULE_NAME_LEN]; #ifdef CONFIG_MODULE_UNLOAD@@ -694,6 +699,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, { struct module *mod; char name[MODULE_NAME_LEN]; + char buf[LAST_UNLOADED_MODULE_NAME_LEN]; int ret, forced = 0; if (!capable(CAP_SYS_MODULE) || modules_disabled)@@ -753,8 +759,8 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, async_synchronize_full(); - /* Store the name of the last unloaded module for diagnostic purposes */ strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); + strcat(last_unloaded_module, module_flags(mod, buf, false));
You replace a bounded string copy by an unbounded strict contat. Should you use strlcat() instead ?
free_module(mod); /* someone could wait for the module in add_unformed_module() */