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cpufreq: mediatek: fix KP caused by handler usage after regulator_put/clk_put

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Any kind of failure in mtk_cpu_dvfs_info_init() will lead to calling
regulator_put() or clk_put() and the KP will occur since the regulator/clk
handlers are used after released in mtk_cpu_dvfs_info_release().

To prevent the usage after regulator_put()/clk_put(), the regulator/clk
handlers are addressed in a way of "Free the Last Thing Style".

Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
Fixes: 4b9ceb757b ("cpufreq: mediatek: Enable clocks and regulators")
Suggested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Suggested-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
This commit is contained in:
Jia-Wei Chang 2023-03-24 18:11:28 +08:00 committed by Viresh Kumar
parent d51c632309
commit d51e106240
1 changed files with 30 additions and 32 deletions
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62
drivers/cpufreq/mediatek-cpufreq.c
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@ -420,7 +420,7 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
ret = PTR_ERR(info->inter_clk);
dev_err_probe(cpu_dev, ret,
"cpu%d: failed to get intermediate clk\n", cpu);
goto out_free_resources;
goto out_free_mux_clock;
}
info->proc_reg = regulator_get_optional(cpu_dev, "proc");
@ -428,13 +428,13 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
ret = PTR_ERR(info->proc_reg);
dev_err_probe(cpu_dev, ret,
"cpu%d: failed to get proc regulator\n", cpu);
goto out_free_resources;
goto out_free_inter_clock;
}
ret = regulator_enable(info->proc_reg);
if (ret) {
dev_warn(cpu_dev, "cpu%d: failed to enable vproc\n", cpu);
goto out_free_resources;
goto out_free_proc_reg;
}
/* Both presence and absence of sram regulator are valid cases. */
@ -442,14 +442,14 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
if (IS_ERR(info->sram_reg)) {
ret = PTR_ERR(info->sram_reg);
if (ret == -EPROBE_DEFER)
goto out_free_resources;
goto out_disable_proc_reg;
info->sram_reg = NULL;
} else {
ret = regulator_enable(info->sram_reg);
if (ret) {
dev_warn(cpu_dev, "cpu%d: failed to enable vsram\n", cpu);
goto out_free_resources;
goto out_free_sram_reg;
}
}
@ -458,13 +458,13 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
if (ret) {
dev_err(cpu_dev,
"cpu%d: failed to get OPP-sharing information\n", cpu);
goto out_free_resources;
goto out_disable_sram_reg;
}
ret = dev_pm_opp_of_cpumask_add_table(&info->cpus);
if (ret) {
dev_warn(cpu_dev, "cpu%d: no OPP table\n", cpu);
goto out_free_resources;
goto out_disable_sram_reg;
}
ret = clk_prepare_enable(info->cpu_clk);
@ -533,43 +533,41 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
out_free_opp_table:
dev_pm_opp_of_cpumask_remove_table(&info->cpus);
out_free_resources:
if (regulator_is_enabled(info->proc_reg))
regulator_disable(info->proc_reg);
if (info->sram_reg && regulator_is_enabled(info->sram_reg))
out_disable_sram_reg:
if (info->sram_reg)
regulator_disable(info->sram_reg);
if (!IS_ERR(info->proc_reg))
regulator_put(info->proc_reg);
if (!IS_ERR(info->sram_reg))
out_free_sram_reg:
if (info->sram_reg)
regulator_put(info->sram_reg);
if (!IS_ERR(info->cpu_clk))
clk_put(info->cpu_clk);
if (!IS_ERR(info->inter_clk))
clk_put(info->inter_clk);
out_disable_proc_reg:
regulator_disable(info->proc_reg);
out_free_proc_reg:
regulator_put(info->proc_reg);
out_free_inter_clock:
clk_put(info->inter_clk);
out_free_mux_clock:
clk_put(info->cpu_clk);
return ret;
}
static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info)
{
if (!IS_ERR(info->proc_reg)) {
regulator_disable(info->proc_reg);
regulator_put(info->proc_reg);
}
if (!IS_ERR(info->sram_reg)) {
regulator_disable(info->proc_reg);
regulator_put(info->proc_reg);
if (info->sram_reg) {
regulator_disable(info->sram_reg);
regulator_put(info->sram_reg);
}
if (!IS_ERR(info->cpu_clk)) {
clk_disable_unprepare(info->cpu_clk);
clk_put(info->cpu_clk);
}
if (!IS_ERR(info->inter_clk)) {
clk_disable_unprepare(info->inter_clk);
clk_put(info->inter_clk);
}
clk_disable_unprepare(info->cpu_clk);
clk_put(info->cpu_clk);
clk_disable_unprepare(info->inter_clk);
clk_put(info->inter_clk);
dev_pm_opp_of_cpumask_remove_table(&info->cpus);
dev_pm_opp_unregister_notifier(info->cpu_dev, &info->opp_nb);
}