From 699ae6241920b0fa837fa57e61f7d5b0e2e65b58 Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Tue, 6 Aug 2024 15:36:07 +0200 Subject: [PATCH] evm: stop avoidably reading i_writecount in evm_file_release The EVM_NEW_FILE flag is unset if the file already existed at the time of open and this can be checked without looking at i_writecount. Not accessing it reduces traffic on the cacheline during parallel open of the same file and drop the evm_file_release routine from second place to bottom of the profile. Fixes: 75a323e604fc ("evm: Make it independent from 'integrity' LSM") Signed-off-by: Mateusz Guzik Reviewed-by: Roberto Sassu Cc: stable@vger.kernel.org # 6.9+ Signed-off-by: Mimi Zohar --- security/integrity/evm/evm_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 6924ed508ebd..377e57e9084f 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -1084,7 +1084,8 @@ static void evm_file_release(struct file *file) if (!S_ISREG(inode->i_mode) || !(mode & FMODE_WRITE)) return; - if (iint && atomic_read(&inode->i_writecount) == 1) + if (iint && iint->flags & EVM_NEW_FILE && + atomic_read(&inode->i_writecount) == 1) iint->flags &= ~EVM_NEW_FILE; } -- 2.50.1