> On Mar 6, 2025, at 7:32 PM, Zhenlei Huang <z...@freebsd.org> wrote: > > > >> On Mar 6, 2025, at 7:03 PM, Mateusz Guzik <m...@freebsd.org >> <mailto:m...@freebsd.org>> wrote: >> >> The branch main has been updated by mjg: >> >> URL: >> https://cgit.FreeBSD.org/src/commit/?id=234683726708cf5212d672d676d30056d4133859 >> >> <https://cgit.freebsd.org/src/commit/?id=234683726708cf5212d672d676d30056d4133859> >> >> commit 234683726708cf5212d672d676d30056d4133859 >> Author: Mateusz Guzik <m...@freebsd.org <mailto:m...@freebsd.org>> >> AuthorDate: 2025-03-06 11:01:49 +0000 >> Commit: Mateusz Guzik <m...@freebsd.org <mailto:m...@freebsd.org>> >> CommitDate: 2025-03-06 11:01:49 +0000 >> >> devclass: make devclass_alloc_unit use M_NOWAIT >> >> The only caller already does this. >> >> The routine can be called with a mutex held making M_WAITOK illegal. >> >> Sponsored by: Rubicon Communications, LLC ("Netgate") >> --- >> sys/kern/subr_bus.c | 8 ++++++-- >> 1 file changed, 6 insertions(+), 2 deletions(-) >> >> diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c >> index 9506e471705c..0422352bba51 100644 >> --- a/sys/kern/subr_bus.c >> +++ b/sys/kern/subr_bus.c >> @@ -1208,6 +1208,7 @@ devclass_get_sysctl_tree(devclass_t dc) >> static int >> devclass_alloc_unit(devclass_t dc, device_t dev, int *unitp) >> { >> + device_t *devices; >> const char *s; >> int unit = *unitp; >> >> @@ -1264,8 +1265,11 @@ devclass_alloc_unit(devclass_t dc, device_t dev, int >> *unitp) >> int newsize; >> >> newsize = unit + 1; >> - dc->devices = reallocf(dc->devices, >> - newsize * sizeof(*dc->devices), M_BUS, M_WAITOK); >> + devices = reallocf(dc->devices, >> + newsize * sizeof(*dc->devices), M_BUS, M_NOWAIT); > > I'd recommend against this. From the commit message of f3d3c63442ff, Warner > said, > > In addition, transition to M_WAITOK since this is a sleepable context > So, the M_WAITOK is intentional. > > Rather than reverting this, the caller devclass_add_device() should use > M_WAITOK. > > ``` > - dev->nameunit = malloc(buflen, M_BUS, M_NOWAIT|M_ZERO); > - if (!dev->nameunit) > - return (ENOMEM); > + dev->nameunit = malloc(buflen, M_BUS, M_WAITOK | M_ZERO); > ```
Emm, sorry for the noise. I missed the commit message, > The routine can be called with a mutex held making M_WAITOK illegal. > > Best regards, > Zhenlei > >> + if (devices == NULL) >> + return (ENOMEM); >> + dc->devices = devices; >> memset(dc->devices + dc->maxunit, 0, >> sizeof(device_t) * (newsize - dc->maxunit)); >> dc->maxunit = newsize;
