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| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-03-01 15:14:04 +0100 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-03-12 18:00:56 -0700 |
| commit | a4107d34f960df99ca07fa8eb022425a804f59f3 (patch) | |
| tree | 2e13e4c5cf1ef5cb52b27a992ac3fb35acf33fd5 /drivers/char/random.c | |
| parent | af6b54e2b5baa54c844573b6d49cc91157bcdd7e (diff) | |
random: do not export add_vmfork_randomness() unless needed
Since add_vmfork_randomness() is only called from vmgenid.o, we can
guard it in CONFIG_VMGENID, similarly to how we do with
add_disk_randomness() and CONFIG_BLOCK. If we ever have multiple things
calling into add_vmfork_randomness(), we can add another shared Kconfig
symbol for that, but for now, this is good enough. Even though
add_vmfork_randomess() is a pretty small function, removing it means
that there are only calls to crng_reseed(false) and none to
crng_reseed(true), which means the compiler can constant propagate the
false, removing branches from crng_reseed() and its descendants.
Additionally, we don't even need the symbol to be exported if
CONFIG_VMGENID is not a module, so conditionalize that too.
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'drivers/char/random.c')
| -rw-r--r-- | drivers/char/random.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 2b323f6bd96c..bc2a4f7e3655 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1168,6 +1168,7 @@ void add_bootloader_randomness(const void *buf, size_t size) } EXPORT_SYMBOL_GPL(add_bootloader_randomness); +#if IS_ENABLED(CONFIG_VMGENID) /* * Handle a new unique VM ID, which is unique, not secret, so we * don't credit it, but we do immediately force a reseed after so @@ -1181,7 +1182,10 @@ void add_vmfork_randomness(const void *unique_vm_id, size_t size) pr_notice("crng reseeded due to virtual machine fork\n"); } } +#if IS_MODULE(CONFIG_VMGENID) EXPORT_SYMBOL_GPL(add_vmfork_randomness); +#endif +#endif struct fast_pool { union { |