On 5/29/20 9:49 AM, Adhemerval Zanella via Libc-alpha wrote: >> + ; ----- child starts here --------- >> + >> + ; Setup TP register (only recent kernels v4.19+ do that) >> + and.f 0, r12, CLONE_SETTLS >> + mov.nz r25, r9 > Do you still need to set it since the minimum supported kernel > for ARC is 5.1 ? Right. > It should be safe for internal glibc usage, since for both pthread > and posix_spawn it blocks all signals including SIGCANCEL and SIGXID. > However this is still small race window if this is called directly > with pthread cancellation or g*uid in multithread. I'm not sure what you mean above. Do you mean not doing this in glibc and even if kernel support didn't exist should be safe internally ? fwiw as mentioned above kernel sets up TP for clone (SETTLS). I detested doing that for a long time, give ABI implications but ended up doing it anyways due to an actual race hit when running uClibc tst-kill6 [1] [1] http://lists.infradead.org/pipermail/linux-snps-arc/2018-October/004480.html _______________________________________________ linux-snps-arc mailing list linux-snps-arc@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-snps-arc
