RepoMirrors/kpatch
1
0
Fork 0
mirror of https://github.com/dynup/kpatch synced 2025-02-05 11:41:29 +00:00
Code Issues Packages Projects Releases Wiki Activity

kmod/core: fix ftrace unregister order

Browse Source 
Currently, when removing a patch module, the ftrace buffer gets flooded
with traces.  This happens because we're clearing the ftrace ops filter
before unregistering the ops, which creates a small window where all
functions are being traced.

We should be doing the unregistering in the reverse order in which we
registered, meaning ops should be unregistered and _then_ the filter
should be cleared.
This commit is contained in:
Josh Poimboeuf 2014-07-01 08:52:59 -05:00
parent d3550bfc3a
commit 2dbae9ae42
1 changed files with 9 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
kmod/core/core.c
View File

@ -459,22 +459,21 @@ static int kpatch_ftrace_remove_func(unsigned long ip)
if (kpatch_get_func(ip))
return 0;
if (kpatch_num_patched == 1) {
ret = unregister_ftrace_function(&kpatch_ftrace_ops);
if (ret) {
pr_err("can't unregister ftrace handler\n");
return ret;
}
}
kpatch_num_patched--;
ret = ftrace_set_filter_ip(&kpatch_ftrace_ops, ip, 1, 0);
if (ret) {
pr_err("can't remove ftrace filter at address 0x%lx\n", ip);
return ret;
}
if (kpatch_num_patched == 1) {
ret = unregister_ftrace_function(&kpatch_ftrace_ops);
if (ret) {
pr_err("can't unregister ftrace handler\n");
ftrace_set_filter_ip(&kpatch_ftrace_ops, ip, 0, 0);
return ret;
}
}
kpatch_num_patched--;
return 0;
}