Commit 4ed45a98 authored by Yongqiang Liu's avatar Yongqiang Liu
Browse files

clk: mediatek: Do a runtime PM get on controllers during probe 

mainline inclusion
from mainline-v6.9-rc5
commit 2f7b1d8b5505efb0057cd1ab85fca206063ea4c3
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9L5DP
CVE: CVE-2024-27002

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2f7b1d8b5505efb0057cd1ab85fca206063ea4c3



--------------------------------

mt8183-mfgcfg has a mutual dependency with genpd during the probing
stage, which leads to a deadlock in the following call stack:

CPU0:  genpd_lock --> clk_prepare_lock
genpd_power_off_work_fn()
 genpd_lock()
 generic_pm_domain::power_off()
    clk_unprepare()
      clk_prepare_lock()

CPU1: clk_prepare_lock --> genpd_lock
clk_register()
  __clk_core_init()
    clk_prepare_lock()
    clk_pm_runtime_get()
      genpd_lock()

Do a runtime PM get at the probe function to make sure clk_register()
won't acquire the genpd lock. Instead of only modifying mt8183-mfgcfg,
do this on all mediatek clock controller probings because we don't
believe this would cause any regression.

Verified on MT8183 and MT8192 Chromebooks.

Fixes: acddfc2c ("clk: mediatek: Add MT8183 clock support")
Signed-off-by: default avatarPin-yen Lin <treapking@chromium.org>

Link: https://lore.kernel.org/r/20240312115249.3341654-1-treapking@chromium.org


Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
Conflicts:
	drivers/clk/mediatek/clk-mt8183-mfgcfg.c
	drivers/clk/mediatek/clk-mtk.c
[Yongqiang: adapt for origin probe function in mt8183-mfgcfg]
Signed-off-by: default avatarYongqiang Liu <liuyongqiang13@huawei.com>
parent 34c4be6c

drivers/clk/mediatek/clk-mt8183-mfgcfg.c

+14 −0
Original line number Diff line number Diff line
@@ -30,14 +30,28 @@ static int clk_mt8183_mfg_probe(struct platform_device *pdev) 
{

	struct clk_onecell_data *clk_data;

	struct device_node *node = pdev->dev.of_node;

	int ret;



	pm_runtime_enable(&pdev->dev);



	/*

	 * Do a pm_runtime_get_sync() to workaround a possible

	 * deadlock between clk_register() and the genpd framework.

	 */

	ret = pm_runtime_get_sync(&pdev->dev);

	if (ret < 0) {

		pm_runtime_put_noidle(&pdev->dev);

		return ret;

	}





	clk_data = mtk_alloc_clk_data(CLK_MFG_NR_CLK);



	mtk_clk_register_gates_with_dev(node, mfg_clks, ARRAY_SIZE(mfg_clks),

			clk_data, &pdev->dev);



	pm_runtime_put(&pdev->dev);



	return of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);

}