| Message ID | 20220705171649.969194-1-hsinyi@chromium.org (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | [v2] PM: domains: Ensure genpd_debugfs_dir exists before remove | expand |
On Wed, Jul 06, 2022 at 01:16:49AM +0800, Hsin-Yi Wang wrote: > Both genpd_debug_add() and genpd_debug_remove() may be called > indirectly by other drivers while genpd_debugfs_dir is not yet > set. For example, drivers can call pm_genpd_init() in probe or > pm_genpd_init() in probe fail/cleanup path: > > pm_genpd_init() > --> genpd_debug_add() > > pm_genpd_remove() > --> genpd_remove() > --> genpd_debug_remove() > > At this time, genpd_debug_init() may not yet be called. > > genpd_debug_add() checks that if genpd_debugfs_dir is NULL, it > will return directly. Make sure this is also checked > in pm_genpd_remove(), otherwise components under debugfs root > which has the same name as other components under pm_genpd may > be accidentally removed, since NULL represents debugfs root. > > Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains") > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> > --- > v1->v2: Add more context in commit message Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Il 05/07/22 19:16, Hsin-Yi Wang ha scritto: > Both genpd_debug_add() and genpd_debug_remove() may be called > indirectly by other drivers while genpd_debugfs_dir is not yet > set. For example, drivers can call pm_genpd_init() in probe or > pm_genpd_init() in probe fail/cleanup path: > > pm_genpd_init() > --> genpd_debug_add() > > pm_genpd_remove() > --> genpd_remove() > --> genpd_debug_remove() > > At this time, genpd_debug_init() may not yet be called. > > genpd_debug_add() checks that if genpd_debugfs_dir is NULL, it > will return directly. Make sure this is also checked > in pm_genpd_remove(), otherwise components under debugfs root > which has the same name as other components under pm_genpd may > be accidentally removed, since NULL represents debugfs root. > > Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains") > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
On Tue, 5 Jul 2022 at 19:17, Hsin-Yi Wang <hsinyi@chromium.org> wrote: > > Both genpd_debug_add() and genpd_debug_remove() may be called > indirectly by other drivers while genpd_debugfs_dir is not yet > set. For example, drivers can call pm_genpd_init() in probe or > pm_genpd_init() in probe fail/cleanup path: > > pm_genpd_init() > --> genpd_debug_add() > > pm_genpd_remove() > --> genpd_remove() > --> genpd_debug_remove() > > At this time, genpd_debug_init() may not yet be called. > > genpd_debug_add() checks that if genpd_debugfs_dir is NULL, it > will return directly. Make sure this is also checked > in pm_genpd_remove(), otherwise components under debugfs root > which has the same name as other components under pm_genpd may > be accidentally removed, since NULL represents debugfs root. > > Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains") > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Kind regards Uffe > --- > v1->v2: Add more context in commit message > --- > drivers/base/power/domain.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index 3e86772d5fac5..5a2e0232862e0 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -222,6 +222,9 @@ static void genpd_debug_remove(struct generic_pm_domain *genpd) > { > struct dentry *d; > > + if (!genpd_debugfs_dir) > + return; > + > d = debugfs_lookup(genpd->name, genpd_debugfs_dir); > debugfs_remove(d); > } > -- > 2.37.0.rc0.161.g10f37bed90-goog >
On Wed, Jul 13, 2022 at 2:02 PM Ulf Hansson <ulf.hansson@linaro.org> wrote: > > On Tue, 5 Jul 2022 at 19:17, Hsin-Yi Wang <hsinyi@chromium.org> wrote: > > > > Both genpd_debug_add() and genpd_debug_remove() may be called > > indirectly by other drivers while genpd_debugfs_dir is not yet > > set. For example, drivers can call pm_genpd_init() in probe or > > pm_genpd_init() in probe fail/cleanup path: > > > > pm_genpd_init() > > --> genpd_debug_add() > > > > pm_genpd_remove() > > --> genpd_remove() > > --> genpd_debug_remove() > > > > At this time, genpd_debug_init() may not yet be called. > > > > genpd_debug_add() checks that if genpd_debugfs_dir is NULL, it > > will return directly. Make sure this is also checked > > in pm_genpd_remove(), otherwise components under debugfs root > > which has the same name as other components under pm_genpd may > > be accidentally removed, since NULL represents debugfs root. > > > > Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains") > > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> > > Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Applied as 5.20 material, thanks! > > --- > > v1->v2: Add more context in commit message > > --- > > drivers/base/power/domain.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > > index 3e86772d5fac5..5a2e0232862e0 100644 > > --- a/drivers/base/power/domain.c > > +++ b/drivers/base/power/domain.c > > @@ -222,6 +222,9 @@ static void genpd_debug_remove(struct generic_pm_domain *genpd) > > { > > struct dentry *d; > > > > + if (!genpd_debugfs_dir) > > + return; > > + > > d = debugfs_lookup(genpd->name, genpd_debugfs_dir); > > debugfs_remove(d); > > } > > -- > > 2.37.0.rc0.161.g10f37bed90-goog > >
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 3e86772d5fac5..5a2e0232862e0 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -222,6 +222,9 @@ static void genpd_debug_remove(struct generic_pm_domain *genpd) { struct dentry *d; + if (!genpd_debugfs_dir) + return; + d = debugfs_lookup(genpd->name, genpd_debugfs_dir); debugfs_remove(d); }
Both genpd_debug_add() and genpd_debug_remove() may be called indirectly by other drivers while genpd_debugfs_dir is not yet set. For example, drivers can call pm_genpd_init() in probe or pm_genpd_init() in probe fail/cleanup path: pm_genpd_init() --> genpd_debug_add() pm_genpd_remove() --> genpd_remove() --> genpd_debug_remove() At this time, genpd_debug_init() may not yet be called. genpd_debug_add() checks that if genpd_debugfs_dir is NULL, it will return directly. Make sure this is also checked in pm_genpd_remove(), otherwise components under debugfs root which has the same name as other components under pm_genpd may be accidentally removed, since NULL represents debugfs root. Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains") Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> --- v1->v2: Add more context in commit message --- drivers/base/power/domain.c | 3 +++ 1 file changed, 3 insertions(+)