From 69cd1ca440a96c85dcedcddfa5e0af6012f60b8b Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Tue, 6 Jan 2026 22:07:29 -0800 Subject: [PATCH] platform/x86: ISST: Check for admin capability for write commands MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit In some SST deployments, administrators want to allow reading SST capabilities for non-root users. This can be achieved by changing file permissions for "/dev/isst_interface", but they still want to prevent any changes to the SST configuration by non-root users. This capability was available before for non-TPMI SST. Extend the same capability for TPMI SST by adding a check for CAP_SYS_ADMIN for all write commands. Signed-off-by: Srinivas Pandruvada Link: https://patch.msgid.link/20260107060729.1634420-1-srinivas.pandruvada@linux.intel.com Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- .../x86/intel/speed_select_if/isst_tpmi_core.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c index 13b11c3a2ec4e..f71d7df03f358 100644 --- a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c +++ b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c @@ -612,7 +612,7 @@ static long isst_if_core_power_state(void __user *argp) return -EINVAL; if (core_power.get_set) { - if (power_domain_info->write_blocked) + if (power_domain_info->write_blocked || !capable(CAP_SYS_ADMIN)) return -EPERM; _write_cp_info("cp_enable", core_power.enable, SST_CP_CONTROL_OFFSET, @@ -659,7 +659,7 @@ static long isst_if_clos_param(void __user *argp) return -EINVAL; if (clos_param.get_set) { - if (power_domain_info->write_blocked) + if (power_domain_info->write_blocked || !capable(CAP_SYS_ADMIN)) return -EPERM; _write_cp_info("clos.min_freq", clos_param.min_freq_mhz, @@ -751,7 +751,8 @@ static long isst_if_clos_assoc(void __user *argp) power_domain_info = &sst_inst->power_domain_info[part][punit_id]; - if (assoc_cmds.get_set && power_domain_info->write_blocked) + if (assoc_cmds.get_set && (power_domain_info->write_blocked || + !capable(CAP_SYS_ADMIN))) return -EPERM; offset = SST_CLOS_ASSOC_0_OFFSET + @@ -928,7 +929,7 @@ static int isst_if_set_perf_level(void __user *argp) if (!power_domain_info) return -EINVAL; - if (power_domain_info->write_blocked) + if (power_domain_info->write_blocked || !capable(CAP_SYS_ADMIN)) return -EPERM; if (!(power_domain_info->pp_header.allowed_level_mask & BIT(perf_level.level))) @@ -988,7 +989,7 @@ static int isst_if_set_perf_feature(void __user *argp) if (!power_domain_info) return -EINVAL; - if (power_domain_info->write_blocked) + if (power_domain_info->write_blocked || !capable(CAP_SYS_ADMIN)) return -EPERM; _write_pp_info("perf_feature", perf_feature.feature, SST_PP_CONTROL_OFFSET, -- 2.47.3