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author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2019-09-18 10:47:48 +0200 |
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committer | Rob Herring <robh@kernel.org> | 2019-09-19 15:33:02 +0200 |
commit | 59e9fcf8772bd97b6d681706fb8c9a972500c524 (patch) | |
tree | bbbfeda32820ee354905a49f604773df184831fb /drivers/of/base.c | |
parent | bus: qcom: fix spelling mistake "ambigous" -> "ambiguous" (diff) | |
download | linux-59e9fcf8772bd97b6d681706fb8c9a972500c524.tar.xz linux-59e9fcf8772bd97b6d681706fb8c9a972500c524.zip |
of: restore old handling of cells_name=NULL in of_*_phandle_with_args()
Before commit e42ee61017f5 ("of: Let of_for_each_phandle fallback to
non-negative cell_count") the iterator functions calling
of_for_each_phandle assumed a cell count of 0 if cells_name was NULL.
This corner case was missed when implementing the fallback logic in
e42ee61017f5 and resulted in an endless loop.
Restore the old behaviour of of_count_phandle_with_args() and
of_parse_phandle_with_args() and add a check to
of_phandle_iterator_init() to prevent a similar failure as a safety
precaution. of_parse_phandle_with_args_map() doesn't need a similar fix
as cells_name isn't NULL there.
Affected drivers are:
- drivers/base/power/domain.c
- drivers/base/power/domain.c
- drivers/clk/ti/clk-dra7-atl.c
- drivers/hwmon/ibmpowernv.c
- drivers/i2c/muxes/i2c-demux-pinctrl.c
- drivers/iommu/mtk_iommu.c
- drivers/net/ethernet/freescale/fman/mac.c
- drivers/opp/of.c
- drivers/perf/arm_dsu_pmu.c
- drivers/regulator/of_regulator.c
- drivers/remoteproc/imx_rproc.c
- drivers/soc/rockchip/pm_domains.c
- sound/soc/fsl/imx-audmix.c
- sound/soc/fsl/imx-audmix.c
- sound/soc/meson/axg-card.c
- sound/soc/samsung/tm2_wm5110.c
- sound/soc/samsung/tm2_wm5110.c
Thanks to Geert Uytterhoeven for reporting the issue, Peter Rosin for
helping pinpoint the actual problem and the testers for confirming this
fix.
Fixes: e42ee61017f5 ("of: Let of_for_each_phandle fallback to non-negative cell_count")
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/of/base.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 2f25d2dfecfa..1d667eb730e1 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -1286,6 +1286,13 @@ int of_phandle_iterator_init(struct of_phandle_iterator *it, memset(it, 0, sizeof(*it)); + /* + * one of cell_count or cells_name must be provided to determine the + * argument length. + */ + if (cell_count < 0 && !cells_name) + return -EINVAL; + list = of_get_property(np, list_name, &size); if (!list) return -ENOENT; @@ -1512,10 +1519,17 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na const char *cells_name, int index, struct of_phandle_args *out_args) { + int cell_count = -1; + if (index < 0) return -EINVAL; - return __of_parse_phandle_with_args(np, list_name, cells_name, -1, - index, out_args); + + /* If cells_name is NULL we assume a cell count of 0 */ + if (!cells_name) + cell_count = 0; + + return __of_parse_phandle_with_args(np, list_name, cells_name, + cell_count, index, out_args); } EXPORT_SYMBOL(of_parse_phandle_with_args); @@ -1765,6 +1779,23 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na struct of_phandle_iterator it; int rc, cur_index = 0; + /* + * If cells_name is NULL we assume a cell count of 0. This makes + * counting the phandles trivial as each 32bit word in the list is a + * phandle and no arguments are to consider. So we don't iterate through + * the list but just use the length to determine the phandle count. + */ + if (!cells_name) { + const __be32 *list; + int size; + + list = of_get_property(np, list_name, &size); + if (!list) + return -ENOENT; + + return size / sizeof(*list); + } + rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1); if (rc) return rc; |