diff options
author | Cyril Hrubis <[email protected]> | 2023-10-02 13:55:51 +0200 |
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committer | Ingo Molnar <[email protected]> | 2023-10-02 15:15:56 +0200 |
commit | 079be8fc630943d9fc70a97807feb73d169ee3fc (patch) | |
tree | e13e47e8b87303fb2f18d3d18245e76d67dc8444 /tools/perf/scripts/python/Perf-Trace-Util | |
parent | 15874a3d27e6405e9d17595f83bd3ca1b6cab16d (diff) |
sched/rt: Disallow writing invalid values to sched_rt_period_us
The validation of the value written to sched_rt_period_us was broken
because:
- the sysclt_sched_rt_period is declared as unsigned int
- parsed by proc_do_intvec()
- the range is asserted after the value parsed by proc_do_intvec()
Because of this negative values written to the file were written into a
unsigned integer that were later on interpreted as large positive
integers which did passed the check:
if (sysclt_sched_rt_period <= 0)
return EINVAL;
This commit fixes the parsing by setting explicit range for both
perid_us and runtime_us into the sched_rt_sysctls table and processes
the values with proc_dointvec_minmax() instead.
Alternatively if we wanted to use full range of unsigned int for the
period value we would have to split the proc_handler and use
proc_douintvec() for it however even the
Documentation/scheduller/sched-rt-group.rst describes the range as 1 to
INT_MAX.
As far as I can tell the only problem this causes is that the sysctl
file allows writing negative values which when read back may confuse
userspace.
There is also a LTP test being submitted for these sysctl files at:
http://patchwork.ozlabs.org/project/ltp/patch/[email protected]/
Signed-off-by: Cyril Hrubis <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Diffstat (limited to 'tools/perf/scripts/python/Perf-Trace-Util')
0 files changed, 0 insertions, 0 deletions