From dc3f5aae06381b43bc9d0d416bd15ee1682940e9 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 29 Nov 2023 12:16:12 +0100 Subject: [PATCH] arm64: idreg-override: Avoid parameq() and parameqn() The only way parameq() and parameqn() deviate from the ordinary string and memory routines is that they ignore the difference between dashes and underscores. Since we copy each command line argument into a buffer before passing it to parameq() and parameqn() numerous times, let's just convert all dashes to underscores just once, and update the alias array accordingly. This also helps reduce the dependency on kernel APIs that are no longer available once we move this code into the early mini C runtime. Signed-off-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20231129111555.3594833-59-ardb@google.com Signed-off-by: Will Deacon --- arch/arm64/kernel/idreg-override.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c index ca1b8d2dbe991..1eca93446345e 100644 --- a/arch/arm64/kernel/idreg-override.c +++ b/arch/arm64/kernel/idreg-override.c @@ -185,8 +185,8 @@ static const struct { char alias[FTR_ALIAS_NAME_LEN]; char feature[FTR_ALIAS_OPTION_LEN]; } aliases[] __initconst = { - { "kvm-arm.mode=nvhe", "id_aa64mmfr1.vh=0" }, - { "kvm-arm.mode=protected", "id_aa64mmfr1.vh=0" }, + { "kvm_arm.mode=nvhe", "id_aa64mmfr1.vh=0" }, + { "kvm_arm.mode=protected", "id_aa64mmfr1.vh=0" }, { "arm64.nosve", "id_aa64pfr0.sve=0" }, { "arm64.nosme", "id_aa64pfr1.sme=0" }, { "arm64.nobti", "id_aa64pfr1.bt=0" }, @@ -215,7 +215,7 @@ static int __init find_field(const char *cmdline, len = snprintf(opt, ARRAY_SIZE(opt), "%s.%s=", reg->name, reg->fields[f].name); - if (!parameqn(cmdline, opt, len)) + if (memcmp(cmdline, opt, len)) return -1; return kstrtou64(cmdline + len, 0, v); @@ -272,23 +272,29 @@ static __init void __parse_cmdline(const char *cmdline, bool parse_aliases) cmdline = skip_spaces(cmdline); - for (len = 0; cmdline[len] && !isspace(cmdline[len]); len++); - if (!len) + /* terminate on "--" appearing on the command line by itself */ + if (cmdline[0] == '-' && cmdline[1] == '-' && isspace(cmdline[2])) return; - len = min(len, ARRAY_SIZE(buf) - 1); - memcpy(buf, cmdline, len); - buf[len] = '\0'; - - if (strcmp(buf, "--") == 0) + for (len = 0; cmdline[len] && !isspace(cmdline[len]); len++) { + if (len >= sizeof(buf) - 1) + break; + if (cmdline[len] == '-') + buf[len] = '_'; + else + buf[len] = cmdline[len]; + } + if (!len) return; + buf[len] = 0; + cmdline += len; match_options(buf); for (i = 0; parse_aliases && i < ARRAY_SIZE(aliases); i++) - if (parameq(buf, aliases[i].alias)) + if (!memcmp(buf, aliases[i].alias, len + 1)) __parse_cmdline(aliases[i].feature, false); } while (1); } -- 2.30.2