From f46ba93944aac3f05211e0d630cdf84955eba2d8 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 28 Apr 2020 23:33:46 +0200 Subject: [PATCH] efi: cache test results of boolean EFI state functions EFI variable access is nowadays subject to rate limiting by the kernel. Thus, let's cache the results of checking them, in order to minimize how often we access them. Fixes: #14828 --- src/basic/efivars.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/src/basic/efivars.c b/src/basic/efivars.c index aa08ad2e278..b79ca8efd77 100644 --- a/src/basic/efivars.c +++ b/src/basic/efivars.c @@ -244,10 +244,16 @@ int efi_set_variable_string(sd_id128_t vendor, const char *name, const char *v) } bool is_efi_boot(void) { - if (detect_container() > 0) - return false; + static int cache = -1; - return access("/sys/firmware/efi/", F_OK) >= 0; + if (cache < 0) { + if (detect_container() > 0) + cache = false; + else + cache = access("/sys/firmware/efi/", F_OK) >= 0; + } + + return cache; } static int read_flag(const char *varname) { @@ -271,11 +277,21 @@ static int read_flag(const char *varname) { } bool is_efi_secure_boot(void) { - return read_flag("SecureBoot") > 0; + static int cache = -1; + + if (cache < 0) + cache = read_flag("SecureBoot"); + + return cache > 0; } bool is_efi_secure_boot_setup_mode(void) { - return read_flag("SetupMode") > 0; + static int cache = -1; + + if (cache < 0) + cache = read_flag("SetupMode"); + + return cache > 0; } int systemd_efi_options_variable(char **line) { -- 2.47.3