lkml.org 
[lkml]   [2023]   [Oct]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v2] KEYS: trusted: Remove redundant static calls usage
    From
    Date
    On Fri, 2023-10-06 at 10:48 +0530, Sumit Garg wrote:
    > Static calls invocations aren't well supported from module __init and
    > __exit functions. Especially the static call from cleanup_trusted() led
    > to a crash on x86 kernel with CONFIG_DEBUG_VIRTUAL=y.
    >
    > However, the usage of static call invocations for trusted_key_init()
    > and trusted_key_exit() don't add any value from either a performance or
    > security perspective. Hence switch to use indirect function calls instead.
    >
    > Note here that although it will fix the current crash report, ultimately
    > the static call infrastructure should be fixed to either support its
    > future usage from module __init and __exit functions or not.
    >
    > Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
    > Link: https://lore.kernel.org/lkml/ZRhKq6e5nF%2F4ZIV1@fedora/#t
    > Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
    > Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
    > ---
    >
    > Changes in v2:
    > - Polish commit message as per comments from Mimi
    >
    >  security/keys/trusted-keys/trusted_core.c | 13 +++++--------
    >  1 file changed, 5 insertions(+), 8 deletions(-)
    >
    > diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
    > index c6fc50d67214..85fb5c22529a 100644
    > --- a/security/keys/trusted-keys/trusted_core.c
    > +++ b/security/keys/trusted-keys/trusted_core.c
    > @@ -44,13 +44,12 @@ static const struct trusted_key_source trusted_key_sources[] = {
    >  #endif
    >  };
    >  
    > -DEFINE_STATIC_CALL_NULL(trusted_key_init, *trusted_key_sources[0].ops->init);
    >  DEFINE_STATIC_CALL_NULL(trusted_key_seal, *trusted_key_sources[0].ops->seal);
    >  DEFINE_STATIC_CALL_NULL(trusted_key_unseal,
    >                         *trusted_key_sources[0].ops->unseal);
    >  DEFINE_STATIC_CALL_NULL(trusted_key_get_random,
    >                         *trusted_key_sources[0].ops->get_random);
    > -DEFINE_STATIC_CALL_NULL(trusted_key_exit, *trusted_key_sources[0].ops->exit);
    > +static void (*trusted_key_exit)(void);
    >  static unsigned char migratable;
    >  
    >  enum {
    > @@ -359,19 +358,16 @@ static int __init init_trusted(void)
    >                 if (!get_random)
    >                         get_random = kernel_get_random;
    >  
    > -               static_call_update(trusted_key_init,
    > -                                  trusted_key_sources[i].ops->init);
    >                 static_call_update(trusted_key_seal,
    >                                    trusted_key_sources[i].ops->seal);
    >                 static_call_update(trusted_key_unseal,
    >                                    trusted_key_sources[i].ops->unseal);
    >                 static_call_update(trusted_key_get_random,
    >                                    get_random);
    > -               static_call_update(trusted_key_exit,
    > -                                  trusted_key_sources[i].ops->exit);
    > +               trusted_key_exit = trusted_key_sources[i].ops->exit;
    >                 migratable = trusted_key_sources[i].ops->migratable;
    >  
    > -               ret = static_call(trusted_key_init)();
    > +               ret = trusted_key_sources[i].ops->init();
    >                 if (!ret)
    >                         break;
    >         }
    > @@ -388,7 +384,8 @@ static int __init init_trusted(void)
    >  
    >  static void __exit cleanup_trusted(void)
    >  {
    > -       static_call_cond(trusted_key_exit)();
    > +       if (trusted_key_exit)
    > +               (*trusted_key_exit)();
    >  }
    >  
    >  late_initcall(init_trusted);

    Would it be less confusing to require trusted_key_exit from each?

    BR, Jarkko

    \
     
     \ /
      Last update: 2023-10-10 14:34    [W:6.592 / U:0.424 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site