mainline inclusion from mainline-v6.16-rc1 commit 45f3763a2122553e548fa0430b77605dc23f00cc category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/9163 CVE: NA Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... ---------------------------------------------------------------------- Optimize cppc_get_perf() with three changes: 1. Change the error kind to "no such device" when pcc_ss_id < 0, as other register value getting functions. 2. Add a check to ensure the pointer 'perf' is no null. 3. Add a check to verify if the register is supported to be read before using it. The logic is: (1) If the register is of the integer type, check whether the register is optional and its value is 0. If yes, the register is not supported. (2) If the register is of other types, a null one is not supported. 4. Return the result of cpc_read() instead of 0. Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> Link: https://patch.msgid.link/20250411093855.982491-3-zhenglifeng1@huawei.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Hongye Lin <linhongye@h-partners.com> --- drivers/acpi/cppc_acpi.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 46953aa0117a..ad5bba812f30 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1224,6 +1224,9 @@ static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); struct cpc_register_resource *reg; + if (perf == NULL) + return -EINVAL; + if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpunum); return -ENODEV; @@ -1231,20 +1234,29 @@ static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) reg = &cpc_desc->cpc_regs[reg_idx]; + if ((reg->type == ACPI_TYPE_INTEGER && IS_OPTIONAL_CPC_REG(reg_idx) && + !reg->cpc_entry.int_value) || (reg->type != ACPI_TYPE_INTEGER && + IS_NULL_REG(®->cpc_entry.reg))) { + pr_debug("CPC register is not supported\n"); + return -EOPNOTSUPP; + } + if (CPC_IN_PCC(reg)) { int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); struct cppc_pcc_data *pcc_ss_data = NULL; - int ret = 0; + int ret; - if (pcc_ss_id < 0) - return -EIO; + if (pcc_ss_id < 0) { + pr_debug("Invalid pcc_ss_id\n"); + return -ENODEV; + } pcc_ss_data = pcc_data[pcc_ss_id]; down_write(&pcc_ss_data->pcc_lock); if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) - cpc_read(cpunum, reg, perf); + ret = cpc_read(cpunum, reg, perf); else ret = -EIO; @@ -1253,9 +1265,7 @@ static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) return ret; } - cpc_read(cpunum, reg, perf); - - return 0; + return cpc_read(cpunum, reg, perf); } static bool cppc_desired_perf_readable(const struct cpc_desc *cpc_desc) -- 2.33.0