RE: Unloaded tainted modules list with tcrypt
From: Elliott, Robert (Servers) <hidden>
Date: 2022-10-11 17:56:02
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-----Original Message----- From: Aaron Tomlin <redacted> Sent: Tuesday, October 11, 2022 10:51 AM To: Elliott, Robert (Servers) <redacted> Cc: linux-modules@vger.kernel.org; linux-kernel@vger.kernel.org Subject: Re: Unloaded tainted modules list with tcrypt On Tue 2022-10-11 00:09 +0000, Elliott, Robert (Servers) wrote:quoted
Changing to == seems to work well - that shows incremented counts rather than new entries: Unloaded tainted modules: tcrypt():40 padlock_aes():1 isst_if_mbox_msr():56pcc_cpufreq():56 acpi_cpufreq():112 Hi Elliott, Please note, any module that does not carry a taint should _not_ be on the aforementioned list. See the following which is already in Linus' tree: commit 47cc75aa92837a9d3f15157d6272ff285585d75d Author: Aaron Tomlin [off-list ref] Date: Fri Oct 7 14:38:12 2022 +0100 module: tracking: Keep a record of tainted unloaded modules only
Thanks. With that change, the list remains blank as tcrypt and the others are never added. The counts of failed loads are mildly interesting (e.g., cpufreq attempts are apparently based on the number of CPU cores present), but there are other ways to observe that.
quoted hunk ↗ jump to hunk
This ensures that no module record/or entry is added to the unloaded_tainted_modules list if it does not carry a taint. Reported-by: Alexey Dobriyan [off-list ref] Fixes: 99bd9956551b ("module: Introduce module unload taint tracking") Signed-off-by: Aaron Tomlin [off-list ref] Acked-by: Luis Chamberlain [off-list ref] Signed-off-by: Linus Torvalds [off-list ref]diff --git a/kernel/module/tracking.c b/kernel/module/tracking.c index a139e63b6f20..26d812e07615 100644 --- a/kernel/module/tracking.c +++ b/kernel/module/tracking.c@@ -22,6 +22,9 @@ int try_add_tainted_module(struct module *mod) module_assert_mutex_or_preempt(); + if (!mod->taints) + goto out; +
One nit - since the out label just leads to a return statement, the gotos in the function would be simpler as "return 0".