| Message ID | 20190918084748.hnjkiq7wc5b35wjh@pengutronix.de (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 59e9fcf8772bd97b6d681706fb8c9a972500c524 |
| Headers | show |
| Series | [v2] of: restore old handling of cells_name=NULL in of_*_phandle_with_args() | expand |
On Wed, Sep 18, 2019 at 3:47 AM Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote: > > 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> > --- > > On Wed, Sep 18, 2019 at 08:01:05AM +0000, Peter Rosin wrote: > > On 2019-09-18 08:38, Uwe Kleine-König wrote: > > > EXPORT_SYMBOL(of_parse_phandle_with_args); > > > > > > @@ -1765,6 +1779,18 @@ 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 */ > > > + if (cells_name == NULL) { > > > > A couple of nits. > > > > I don't know if there are other considerations, but in the previous two > > hunks you use !cells_name instead of comparing explicitly with NULL. > > Personally, I find the shorter form more readable, and in the name of > > consistency bla bla... > > Ack, changed to !cells_name here, too. > > > > > Also, the comment explaining this NULL-check didn't really make sense > > to me until I realized that knowing the cell count to be zero makes > > counting trivial. Something along those lines should perhaps be in the > > comment? > > You're right, I extended the comment a bit. > > > But as I said, these are nits. Feel free to ignore. > > I considered resending already anyhow as I fatfingerd my email address. > this is fixed now, too. Additionally I fixed a typo in one of the > comments. > > Thanks for your feedback. > > Best regards > Uwe > > drivers/of/base.c | 35 +++++++++++++++++++++++++++++++++-- > 1 file changed, 33 insertions(+), 2 deletions(-) Can I get a proper patch please. Rob
On Wed, Sep 18, 2019 at 03:09:06PM -0500, Rob Herring wrote: > On Wed, Sep 18, 2019 at 3:47 AM Uwe Kleine-König > <u.kleine-koenig@pengutronix.de> wrote: > > > > 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> > > --- > > > > On Wed, Sep 18, 2019 at 08:01:05AM +0000, Peter Rosin wrote: > > > On 2019-09-18 08:38, Uwe Kleine-König wrote: > > > > EXPORT_SYMBOL(of_parse_phandle_with_args); > > > > > > > > @@ -1765,6 +1779,18 @@ 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 */ > > > > + if (cells_name == NULL) { > > > > > > A couple of nits. > > > > > > I don't know if there are other considerations, but in the previous two > > > hunks you use !cells_name instead of comparing explicitly with NULL. > > > Personally, I find the shorter form more readable, and in the name of > > > consistency bla bla... > > > > Ack, changed to !cells_name here, too. > > > > > > > > Also, the comment explaining this NULL-check didn't really make sense > > > to me until I realized that knowing the cell count to be zero makes > > > counting trivial. Something along those lines should perhaps be in the > > > comment? > > > > You're right, I extended the comment a bit. > > > > > But as I said, these are nits. Feel free to ignore. > > > > I considered resending already anyhow as I fatfingerd my email address. > > this is fixed now, too. Additionally I fixed a typo in one of the > > comments. > > > > Thanks for your feedback. > > > > Best regards > > Uwe > > > > drivers/of/base.c | 35 +++++++++++++++++++++++++++++++++-- > > 1 file changed, 33 insertions(+), 2 deletions(-) > > Can I get a proper patch please. I don't understand what is wrong with my patch. Can you please expand what you are missing? I just tried to git-am it and the result looks fine. Best regards Uwe
On Wed, Sep 18, 2019 at 10:19:54PM +0200, Uwe Kleine-König wrote: > On Wed, Sep 18, 2019 at 03:09:06PM -0500, Rob Herring wrote: > > Can I get a proper patch please. > > I don't understand what is wrong with my patch. Can you please expand > what you are missing? I just tried to git-am it and the result looks > fine. I see that the commit this patch is fixing isn't in Linus' tree yet. Do you want instead of this commit fixing the previous one a single good patch that replaces e42ee61017f5 ("of: Let of_for_each_phandle fallback to non-negative cell_count")? Best regards Uwe
On Wed, 18 Sep 2019 10:47:48 +0200, Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= wrote: > 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> > --- > > On Wed, Sep 18, 2019 at 08:01:05AM +0000, Peter Rosin wrote: > > On 2019-09-18 08:38, Uwe Kleine-König wrote: > > > EXPORT_SYMBOL(of_parse_phandle_with_args); > > > > > > @@ -1765,6 +1779,18 @@ 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 */ > > > + if (cells_name == NULL) { > > > > A couple of nits. > > > > I don't know if there are other considerations, but in the previous two > > hunks you use !cells_name instead of comparing explicitly with NULL. > > Personally, I find the shorter form more readable, and in the name of > > consistency bla bla... > > Ack, changed to !cells_name here, too. > > > > > Also, the comment explaining this NULL-check didn't really make sense > > to me until I realized that knowing the cell count to be zero makes > > counting trivial. Something along those lines should perhaps be in the > > comment? > > You're right, I extended the comment a bit. > > > But as I said, these are nits. Feel free to ignore. > > I considered resending already anyhow as I fatfingerd my email address. > this is fixed now, too. Additionally I fixed a typo in one of the > comments. > > Thanks for your feedback. > > Best regards > Uwe > > drivers/of/base.c | 35 +++++++++++++++++++++++++++++++++-- > 1 file changed, 33 insertions(+), 2 deletions(-) > Applied, thanks. Rob
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;
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> --- On Wed, Sep 18, 2019 at 08:01:05AM +0000, Peter Rosin wrote: > On 2019-09-18 08:38, Uwe Kleine-König wrote: > > EXPORT_SYMBOL(of_parse_phandle_with_args); > > > > @@ -1765,6 +1779,18 @@ 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 */ > > + if (cells_name == NULL) { > > A couple of nits. > > I don't know if there are other considerations, but in the previous two > hunks you use !cells_name instead of comparing explicitly with NULL. > Personally, I find the shorter form more readable, and in the name of > consistency bla bla... Ack, changed to !cells_name here, too. > > Also, the comment explaining this NULL-check didn't really make sense > to me until I realized that knowing the cell count to be zero makes > counting trivial. Something along those lines should perhaps be in the > comment? You're right, I extended the comment a bit. > But as I said, these are nits. Feel free to ignore. I considered resending already anyhow as I fatfingerd my email address. this is fixed now, too. Additionally I fixed a typo in one of the comments. Thanks for your feedback. Best regards Uwe drivers/of/base.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-)