Christophe Leroy <christophe.le...@csgroup.eu> writes: > Le 27/08/2024 à 11:12, Ritesh Harjani (IBM) a écrit : >> [Vous ne recevez pas souvent de courriers de ritesh.l...@gmail.com. >> Découvrez pourquoi ceci est important à >> https://aka.ms/LearnAboutSenderIdentification ] >> >> Use pr_warn_once instead of WARN_ON_ONCE as discussed here [1] >> for printing possible use of set_memory_* on linear map on Hash. >> >> [1]: https://lore.kernel.org/all/877cc2fpi2.fsf@mail.lhotse/#t >> >> Signed-off-by: Ritesh Harjani (IBM) <ritesh.l...@gmail.com> >> --- >> arch/powerpc/mm/pageattr.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/arch/powerpc/mm/pageattr.c b/arch/powerpc/mm/pageattr.c >> index ac22bf28086f..c8c2d664c6f3 100644 >> --- a/arch/powerpc/mm/pageattr.c >> +++ b/arch/powerpc/mm/pageattr.c >> @@ -94,8 +94,11 @@ int change_memory_attr(unsigned long addr, int numpages, >> long action) >> if (!radix_enabled()) { >> int region = get_region_id(addr); >> >> - if (WARN_ON_ONCE(region != VMALLOC_REGION_ID && region != >> IO_REGION_ID)) >> + if (region != VMALLOC_REGION_ID && region != IO_REGION_ID) { >> + pr_warn_once("%s: possible use of set_memory_* on >> linear map on Hash from (%ps)\n", >> + __func__, >> __builtin_return_address(0)); > > Is it really only linear map ? > > What about "possible user of set_memory_* outside of vmalloc or io region.
"warning: possible user of set_memory_* outside of vmalloc and io region." I am thinking of adding a word "warning" too. I can make above change and send v2. > > Maybe a show_stack() would also be worth it ? IMO, since we have the caller, we need not pollute the dmesg with the entire call stack. Besides I am not aware of dump_stack_once() style prints. > > > But in principle I think it would be better to keep the WARN_ONCE until > we can add __must_check to set_memory_xxx() functions to be sure all > callers check the result, as mandated by > https://github.com/KSPP/linux/issues/7 Fixing the callers to check the return value is something that need not depend on this change no? The intention of this change is to mainly remove the heavy WARN_ON_ONCE from powerpc specific change_memory_attr() and convert to printk warn. -ritesh
