Russell King - ARM Linux admin <li...@armlinux.org.uk> 于2021年3月25日周四 下午6:06写道： > > On Thu, Mar 25, 2021 at 05:50:49PM +0800, Liu Xiang wrote: > > When CONFIG_HARDEN_BRANCH_PREDICTOR is selected and user aborts occur, > > there is a warning: > > > > BUG: using smp_processor_id() in preemptible [00000000] code: errnotest/577 > > caller is __do_user_fault.constprop.4+0x24/0x88 > > CPU: 1 PID: 577 Comm: errnotest Not tainted > > 4.14.188-rt87-fmsh-00004-g58055877a #1 > > Hardware name: FMSH PSOC Platform > > [<8010d6d4>] (unwind_backtrace) from [<8010a228>] (show_stack+0x10/0x14) > > [<8010a228>] (show_stack) from [<80698f44>] (dump_stack+0x7c/0x98) > > [<80698f44>] (dump_stack) from [<803d17d0>] > > (check_preemption_disabled+0xc4/0xfc) > > [<803d17d0>] (check_preemption_disabled) from [<80110eb8>] > > (__do_user_fault.constprop.4+0x24/0x88) > > [<80110eb8>] (__do_user_fault.constprop.4) from [<801112e4>] > > (do_page_fault+0x2dc/0x310) > > [<801112e4>] (do_page_fault) from [<801012a8>] (do_DataAbort+0x38/0xb8) > > [<801012a8>] (do_DataAbort) from [<8010b03c>] (__dabt_usr+0x3c/0x40) > > Exception stack(0xb21d1fb0 to 0xb21d1ff8) > > 1fa0: fffffff4 00000000 00000054 > > fffffff4 > > 1fc0: 00000000 00000000 7ed81cc8 7ed81ca0 0007a440 00000000 00000000 > > 00000000 > > 1fe0: 00000000 7ed81ca0 00010493 0001f330 20030010 ffffffff > > This is not the right fix - preemption is supposed to be disabled before > this function is called. I'm not sure at the present time what the right > fix is supposed to be because I've forgotten most of the background > behind why this was placed where it is. > > -- > RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ > FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
I have tested with the current mainline kernel, the warning still exists. [ 14.404322] BUG: using smp_processor_id() in preemptible [00000000] code: errnotest/81 [ 14.404795] caller is __do_user_fault.constprop.5+0x54/0x7c [ 14.405163] CPU: 1 PID: 81 Comm: errnotest Not tainted 5.12.0-rc4-ge97a94a30e55-dirty #6 [ 14.405616] Hardware name: ARM-Versatile Express [ 14.406475] [<c010af58>] (unwind_backtrace) from [<c01064c4>] (show_stack+0x10/0x14) [ 14.407018] [<c01064c4>] (show_stack) from [<c0a6a0cc>] (dump_stack+0x8c/0xa0) [ 14.407398] [<c0a6a0cc>] (dump_stack) from [<c0a6d0a4>] (check_preemption_disabled+0x114/0x118) [ 14.407906] [<c0a6d0a4>] (check_preemption_disabled) from [<c010ef68>] (__do_user_fault.constprop.5+0x54/0x7c) [ 14.408367] [<c010ef68>] (__do_user_fault.constprop.5) from [<c010f274>] (do_page_fault+0x208/0x3bc) [ 14.408907] [<c010f274>] (do_page_fault) from [<c010f588>] (do_DataAbort+0x3c/0xbc) [ 14.409266] [<c010f588>] (do_DataAbort) from [<c0100e7c>] (__dabt_usr+0x3c/0x40) [ 14.409721] Exception stack(0xc285ffb0 to 0xc285fff8) [ 14.410099] ffa0: fffffff4 00000000 00000054 fffffff4 [ 14.411000] ffc0: 00000000 00000000 bed90d28 bed90d00 0007a440 00000000 00000000 00000000 [ 14.411386] ffe0: 00000000 bed90d00 00010493 0001f330 20030010 ffffffff Segmentation fault
