linux-stable.git/drivers/opp/core.c, branch linux-5.15.y

OPP: Fix passing 0 to PTR_ERR in _opp_attach_genpd()

2023-09-19T10:22:31+00:00

[ Upstream commit d920920f85a82c1c806a4143871a0e8f534732f2 ]

If dev_pm_domain_attach_by_name() returns NULL, then 0 will be passed to
PTR_ERR() as reported by the smatch warning below:

drivers/opp/core.c:2456 _opp_attach_genpd() warn: passing zero to 'PTR_ERR'

Fix it by checking for the non-NULL virt_dev pointer before passing it to
PTR_ERR. Otherwise return -ENODEV.

Fixes: 4ea9496cbc95 ("opp: Fix error check in dev_pm_opp_attach_genpd()")
Signed-off-by: Manivannan Sadhasivam 
Signed-off-by: Viresh Kumar 
Signed-off-by: Sasha Levin

opp: Fix use-after-free in lazy_opp_tables after probe deferral

2023-07-23T11:47:54+00:00

commit b2a2ab039bd58f51355e33d7d3fc64605d7f870d upstream.

When dev_pm_opp_of_find_icc_paths() in _allocate_opp_table() returns
-EPROBE_DEFER, the opp_table is freed again, to wait until all the
interconnect paths are available.

However, if the OPP table is using required-opps then it may already
have been added to the global lazy_opp_tables list. The error path
does not remove the opp_table from the list again.

This can cause crashes later when the provider of the required-opps
is added, since we will iterate over OPP tables that have already been
freed. E.g.:

  Unable to handle kernel NULL pointer dereference when read
  CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.4.0-rc3
  PC is at _of_add_opp_table_v2 (include/linux/of.h:949
  drivers/opp/of.c:98 drivers/opp/of.c:344 drivers/opp/of.c:404
  drivers/opp/of.c:1032) -> lazy_link_required_opp_table()

Fix this by calling _of_clear_opp_table() to remove the opp_table from
the list and clear other allocated resources. While at it, also add the
missing mutex_destroy() calls in the error path.

Cc: stable@vger.kernel.org
Suggested-by: Viresh Kumar 
Fixes: 7eba0c7641b0 ("opp: Allow lazy-linking of required-opps")
Signed-off-by: Stephan Gerhold 
Signed-off-by: Viresh Kumar 
Signed-off-by: Greg Kroah-Hartman

opp: Fix error check in dev_pm_opp_attach_genpd()

2022-08-17T12:24:01+00:00

[ Upstream commit 4ea9496cbc959eb5c78f3e379199aca9ef4e386b ]

dev_pm_domain_attach_by_name() may return NULL in some cases,
so IS_ERR() doesn't meet the requirements. Thus fix it.

Fixes: 6319aee10e53 ("opp: Attach genpds to devices from within OPP core")
Signed-off-by: Tang Bin 
[ Viresh: Replace ENODATA with ENODEV ]
Signed-off-by: Viresh Kumar 
Signed-off-by: Sasha Levin

opp: core: Check for pending links before reading required_opp pointers

2021-08-23T07:14:55+00:00

Commit 4fa82a87ba55 ("opp: Allow required-opps to be used for non genpd
use cases") dereferences the pointers in required_opp_tables but these
might be set to an ERR_PTR if the list still has lazy links pending,
resulting in segfaults.  Prior to this patch IS_ERR was also checked on
required_opp_tables[i] before reading ->is_genpd inside
_opp_table_alloc_required_tables, which is at the same time the
predicate to add this table to the lazy list.  This segfault is solved
by reordering the checks to bail on lazy pending tables before reading
->is_genpd.

Fixes: 4fa82a87ba55 ("opp: Allow required-opps to be used for non genpd use cases")
Reviewed-by: AngeloGioacchino Del Regno 
Signed-off-by: Marijn Suijten 
Signed-off-by: Viresh Kumar

opp: Drop empty-table checks from _put functions

2021-08-16T04:12:08+00:00

The current_opp is released only when whole OPP table is released,
otherwise it's only marked as removed by dev_pm_opp_remove_table().
Functions like dev_pm_opp_put_clkname() and dev_pm_opp_put_supported_hw()
are checking whether OPP table is empty and it's not if current_opp is
set since it holds the refcount of OPP, this produces a noisy warning
from these functions about busy OPP table. Remove the checks to fix it.

Cc: stable@vger.kernel.org
Fixes: 81c4d8a3c414 ("opp: Keep track of currently programmed OPP")
Signed-off-by: Dmitry Osipenko 
Signed-off-by: Viresh Kumar

opp: Allow required-opps to be used for non genpd use cases

2021-06-18T03:30:55+00:00

Don't limit required_opp_table to genpd only. One possible use case is
cpufreq based devfreq governor, which can use required-opps property to
derive devfreq from cpufreq.

Though the OPP core still doesn't support non-genpd required-opps in
_set_required_opps().

Suggested-by: Chanwoo Choi 
Signed-off-by: Hsin-Yi Wang 
[ Viresh: Update _set_required_opps() to check for genpd ]
Signed-off-by: Viresh Kumar

opp: Change return type of devm_pm_opp_attach_genpd()

2021-03-16T04:44:11+00:00

Make devm_pm_opp_attach_genpd() to return error code instead of
opp_table pointer in order to have return type consistent with the
other resource-managed OPP helpers.

Signed-off-by: Dmitry Osipenko 
Signed-off-by: Viresh Kumar

opp: Change return type of devm_pm_opp_register_set_opp_helper()

2021-03-16T04:44:11+00:00

Make devm_pm_opp_register_set_opp_helper() to return error code instead
of opp_table pointer in order to have return type consistent with the
other resource-managed OPP helpers.

Signed-off-by: Dmitry Osipenko 
Signed-off-by: Viresh Kumar

opp: Add devres wrapper for dev_pm_opp_set_supported_hw

2021-03-15T03:56:53+00:00

Add devres wrapper for dev_pm_opp_set_supported_hw() to simplify drivers
code.

Signed-off-by: Yangtao Li 
Signed-off-by: Dmitry Osipenko 
Signed-off-by: Viresh Kumar

opp: Add devres wrapper for dev_pm_opp_set_regulators

2021-03-15T03:56:53+00:00

Add devres wrapper for dev_pm_opp_set_regulators() to simplify drivers
code.

Signed-off-by: Yangtao Li 
Signed-off-by: Dmitry Osipenko 
Signed-off-by: Viresh Kumar