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2021-09-03powerpc: Re-enable ARCH_ENABLE_SPLIT_PMD_PTLOCKLukas Bulwahn1-1/+1
commit 310d2e83cb9b7f1e7232319880e3fcb57592fa10 upstream. Commit 66f24fa766e3 ("mm: drop redundant ARCH_ENABLE_SPLIT_PMD_PTLOCK") broke PMD split page table lock for powerpc. It selects the non-existent config ARCH_ENABLE_PMD_SPLIT_PTLOCK in arch/powerpc/platforms/Kconfig.cputype, but clearly intended to select ARCH_ENABLE_SPLIT_PMD_PTLOCK (notice the word swapping!), as that commit did for all other architectures. Fix it by selecting the correct symbol ARCH_ENABLE_SPLIT_PMD_PTLOCK. Fixes: 66f24fa766e3 ("mm: drop redundant ARCH_ENABLE_SPLIT_PMD_PTLOCK") Cc: stable@vger.kernel.org # v5.13+ Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Reviewed-by: Daniel Axtens <dja@axtens.net> [mpe: Reword change log to make it clear this is a bug fix] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210819113954.17515-3-lukas.bulwahn@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-26powerpc/32s: Fix random crashes by adding isync() after locking/unlocking KUEPChristophe Leroy1-0/+20
[ Upstream commit ef486bf448a057a6e2d50e40ae879f7add6585da ] Commit b5efec00b671 ("powerpc/32s: Move KUEP locking/unlocking in C") removed the 'isync' instruction after adding/removing NX bit in user segments. The reasoning behind this change was that when setting the NX bit we don't mind it taking effect with delay as the kernel never executes text from userspace, and when clearing the NX bit this is to return to userspace and then the 'rfi' should synchronise the context. However, it looks like on book3s/32 having a hash page table, at least on the G3 processor, we get an unexpected fault from userspace, then this is followed by something wrong in the verification of MSR_PR at end of another interrupt. This is fixed by adding back the removed isync() following update of NX bit in user segment registers. Only do it for cores with an hash table, as 603 cores don't exhibit that problem and the two isync increase ./null_syscall selftest by 6 cycles on an MPC 832x. First problem: unexpected WARN_ON() for mysterious PROTFAULT WARNING: CPU: 0 PID: 1660 at arch/powerpc/mm/fault.c:354 do_page_fault+0x6c/0x5b0 Modules linked in: CPU: 0 PID: 1660 Comm: Xorg Not tainted 5.13.0-pmac-00028-gb3c15b60339a #40 NIP: c001b5c8 LR: c001b6f8 CTR: 00000000 REGS: e2d09e40 TRAP: 0700 Not tainted (5.13.0-pmac-00028-gb3c15b60339a) MSR: 00021032 <ME,IR,DR,RI> CR: 42d04f30 XER: 20000000 GPR00: c000424c e2d09f00 c301b680 e2d09f40 0000001e 42000000 00cba028 00000000 GPR08: 08000000 48000010 c301b680 e2d09f30 22d09f30 00c1fff0 00cba000 a7b7ba4c GPR16: 00000031 00000000 00000000 00000000 00000000 00000000 a7b7b0d0 00c5c010 GPR24: a7b7b64c a7b7d2f0 00000004 00000000 c1efa6c0 00cba02c 00000300 e2d09f40 NIP [c001b5c8] do_page_fault+0x6c/0x5b0 LR [c001b6f8] do_page_fault+0x19c/0x5b0 Call Trace: [e2d09f00] [e2d09f04] 0xe2d09f04 (unreliable) [e2d09f30] [c000424c] DataAccess_virt+0xd4/0xe4 --- interrupt: 300 at 0xa7a261dc NIP: a7a261dc LR: a7a253bc CTR: 00000000 REGS: e2d09f40 TRAP: 0300 Not tainted (5.13.0-pmac-00028-gb3c15b60339a) MSR: 0000d032 <EE,PR,ME,IR,DR,RI> CR: 228428e2 XER: 20000000 DAR: 00cba02c DSISR: 42000000 GPR00: a7a27448 afa6b0e0 a74c35c0 a7b7b614 0000001e a7b7b614 00cba028 00000000 GPR08: 00020fd9 00000031 00cb9ff8 a7a273b0 220028e2 00c1fff0 00cba000 a7b7ba4c GPR16: 00000031 00000000 00000000 00000000 00000000 00000000 a7b7b0d0 00c5c010 GPR24: a7b7b64c a7b7d2f0 00000004 00000002 0000001e a7b7b614 a7b7aff4 00000030 NIP [a7a261dc] 0xa7a261dc LR [a7a253bc] 0xa7a253bc --- interrupt: 300 Instruction dump: 7c4a1378 810300a0 75278410 83820298 83a300a4 553b018c 551e0036 4082038c 2e1b0000 40920228 75280800 41820220 <0fe00000> 3b600000 41920214 81420594 Second problem: MSR PR is seen unset allthough the interrupt frame shows it set kernel BUG at arch/powerpc/kernel/interrupt.c:458! Oops: Exception in kernel mode, sig: 5 [#1] BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac Modules linked in: CPU: 0 PID: 1660 Comm: Xorg Tainted: G W 5.13.0-pmac-00028-gb3c15b60339a #40 NIP: c0011434 LR: c001629c CTR: 00000000 REGS: e2d09e70 TRAP: 0700 Tainted: G W (5.13.0-pmac-00028-gb3c15b60339a) MSR: 00029032 <EE,ME,IR,DR,RI> CR: 42d09f30 XER: 00000000 GPR00: 00000000 e2d09f30 c301b680 e2d09f40 83440000 c44d0e68 e2d09e8c 00000000 GPR08: 00000002 00dc228a 00004000 e2d09f30 22d09f30 00c1fff0 afa6ceb4 00c26144 GPR16: 00c25fb8 00c26140 afa6ceb8 90000000 00c944d8 0000001c 00000000 00200000 GPR24: 00000000 000001fb afa6d1b4 00000001 00000000 a539a2a0 a530fd80 00000089 NIP [c0011434] interrupt_exit_kernel_prepare+0x10/0x70 LR [c001629c] interrupt_return+0x9c/0x144 Call Trace: [e2d09f30] [c000424c] DataAccess_virt+0xd4/0xe4 (unreliable) --- interrupt: 300 at 0xa09be008 NIP: a09be008 LR: a09bdfe8 CTR: a09bdfc0 REGS: e2d09f40 TRAP: 0300 Tainted: G W (5.13.0-pmac-00028-gb3c15b60339a) MSR: 0000d032 <EE,PR,ME,IR,DR,RI> CR: 420028e2 XER: 20000000 DAR: a539a308 DSISR: 0a000000 GPR00: a7b90d50 afa6b2d0 a74c35c0 a0a8b690 a0a8b698 a5365d70 a4fa82a8 00000004 GPR08: 00000000 a09bdfc0 00000000 a5360000 a09bde7c 00c1fff0 afa6ceb4 00c26144 GPR16: 00c25fb8 00c26140 afa6ceb8 90000000 00c944d8 0000001c 00000000 00200000 GPR24: 00000000 000001fb afa6d1b4 00000001 00000000 a539a2a0 a530fd80 00000089 NIP [a09be008] 0xa09be008 LR [a09bdfe8] 0xa09bdfe8 --- interrupt: 300 Instruction dump: 80010024 83e1001c 7c0803a6 4bffff80 3bc00800 4bffffd0 486b42fd 4bffffcc 81430084 71480002 41820038 554a0462 <0f0a0000> 80620060 74630001 40820034 Fixes: b5efec00b671 ("powerpc/32s: Move KUEP locking/unlocking in C") Cc: stable@vger.kernel.org # v5.13+ Reported-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4856f5574906e2aec0522be17bf3848a22b2cd0b.1629269345.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-26powerpc/32s: Refactor update of user segment registersChristophe Leroy4-41/+49
[ Upstream commit 91bb30822a2e1d7900f9f42e9e92647a9015f979 ] KUEP implements the update of user segment registers. Move it into mmu-hash.h in order to use it from other places. And inline kuep_lock() and kuep_unlock(). Inlining kuep_lock() is important for system_call_exception(), otherwise system_call_exception() has to save into stack the system call parameters that are used just after, and doing that takes more instructions than kuep_lock() itself. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/24591ca480d14a62ef910e38a5273d551262c4a2.1622708530.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-26powerpc/32s: Move setup_{kuep/kuap}() into {kuep/kuap}.cChristophe Leroy4-20/+20
[ Upstream commit 91ec66719d4c5c0e7b4e32585b01881660d1bc53 ] Avoids the #ifdef in mmu.c Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0b7a13d414837e58264edc336b89c2fe9f35f9bc.1622708530.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-18powerpc/32: Fix critical and debug interrupts on BOOKEChristophe Leroy3-41/+33
commit b5cfc9cd7b0426e94ffd9e9ed79d1b00ace7780a upstream. 32 bits BOOKE have special interrupts for debug and other critical events. When handling those interrupts, dedicated registers are saved in the stack frame in addition to the standard registers, leading to a shift of the pt_regs struct. Since commit db297c3b07af ("powerpc/32: Don't save thread.regs on interrupt entry"), the pt_regs struct is expected to be at the same place all the time. Instead of handling a special struct in addition to pt_regs, just add those special registers to struct pt_regs. Fixes: db297c3b07af ("powerpc/32: Don't save thread.regs on interrupt entry") Cc: stable@vger.kernel.org Reported-by: Radu Rendec <radu.rendec@gmail.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/028d5483b4851b01ea4334d0751e7f260419092b.1625637264.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-18powerpc/xive: Do not skip CPU-less nodes when creating the IPIsCédric Le Goater1-11/+24
commit cbc06f051c524dcfe52ef0d1f30647828e226d30 upstream. On PowerVM, CPU-less nodes can be populated with hot-plugged CPUs at runtime. Today, the IPI is not created for such nodes, and hot-plugged CPUs use a bogus IPI, which leads to soft lockups. We can not directly allocate and request the IPI on demand because bringup_up() is called under the IRQ sparse lock. The alternative is to allocate the IPIs for all possible nodes at startup and to request the mapping on demand when the first CPU of a node is brought up. Fixes: 7dcc37b3eff9 ("powerpc/xive: Map one IPI interrupt per node") Cc: stable@vger.kernel.org # v5.13 Reported-by: Geetika Moolchandani <Geetika.Moolchandani1@ibm.com> Signed-off-by: Cédric Le Goater <clg@kaod.org> Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210807072057.184698-1-clg@kaod.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-18powerpc/smp: Fix OOPS in topology_init()Christophe Leroy1-1/+1
commit 8241461536f21bbe51308a6916d1c9fb2e6b75a7 upstream. Running an SMP kernel on an UP platform not prepared for it, I encountered the following OOPS: BUG: Kernel NULL pointer dereference on read at 0x00000034 Faulting instruction address: 0xc0a04110 Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=4K SMP NR_CPUS=2 CMPCPRO Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-pmac-00001-g230fedfaad21 #5234 NIP: c0a04110 LR: c0a040d8 CTR: c0a04084 REGS: e100dda0 TRAP: 0300 Not tainted (5.13.0-pmac-00001-g230fedfaad21) MSR: 00009032 <EE,ME,IR,DR,RI> CR: 84000284 XER: 00000000 DAR: 00000034 DSISR: 20000000 GPR00: c0006bd4 e100de60 c1033320 00000000 00000000 c0942274 00000000 00000000 GPR08: 00000000 00000000 00000001 00000063 00000007 00000000 c0006f30 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000005 GPR24: c0c67d74 c0c67f1c c0c60000 c0c67d70 c0c0c558 1efdf000 c0c00020 00000000 NIP [c0a04110] topology_init+0x8c/0x138 LR [c0a040d8] topology_init+0x54/0x138 Call Trace: [e100de60] [80808080] 0x80808080 (unreliable) [e100de90] [c0006bd4] do_one_initcall+0x48/0x1bc [e100def0] [c0a0150c] kernel_init_freeable+0x1c8/0x278 [e100df20] [c0006f44] kernel_init+0x14/0x10c [e100df30] [c00190fc] ret_from_kernel_thread+0x14/0x1c Instruction dump: 7c692e70 7d290194 7c035040 7c7f1b78 5529103a 546706fe 5468103a 39400001 7c641b78 40800054 80c690b4 7fb9402e <81060034> 7fbeea14 2c080000 7fa3eb78 ---[ end trace b246ffbc6bbbb6fb ]--- Fix it by checking smp_ops before using it, as already done in several other places in the arch/powerpc/kernel/smp.c Fixes: 39f87561454d ("powerpc/smp: Move ppc_md.cpu_die() to smp_ops.cpu_offline_self()") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/75287841cbb8740edd44880fe60be66d489160d9.1628097995.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-18powerpc/32s: Fix napping restore in data storage interrupt (DSI)Christophe Leroy1-1/+1
commit 62376365048878f770d8b7d11b89b8b3e18018f1 upstream. When a DSI (Data Storage Interrupt) is taken while in NAP mode, r11 doesn't survive the call to power_save_ppc32_restore(). So use r1 instead of r11 as they both contain the virtual stack pointer at that point. Fixes: 4c0104a83fc3 ("powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE") Cc: stable@vger.kernel.org # v5.13+ Reported-by: Finn Thain <fthain@linux-m68k.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/731694e0885271f6ee9ffc179eb4bcee78313682.1628003562.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-18powerpc/pseries: Fix update of LPAR security flavor after LPMLaurent Dufour1-2/+3
commit c18956e6e0b95f78dad2773ecc8c61a9e41f6405 upstream. After LPM, when migrating from a system with security mitigation enabled to a system with mitigation disabled, the security flavor exposed in /proc is not correctly set back to 0. Do not assume the value of the security flavor is set to 0 when entering init_cpu_char_feature_flags(), so when called after a LPM, the value is set correctly even if the mitigation are not turned off. Fixes: 6ce56e1ac380 ("powerpc/pseries: export LPAR security flavor in lparcfg") Cc: stable@vger.kernel.org # v5.13+ Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210805152308.33988-1-ldufour@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-18powerpc/interrupt: Do not call single_step_exception() from other exceptionsChristophe Leroy1-2/+7
commit 01fcac8e4dfc112f420dcaeb70056a74e326cacf upstream. single_step_exception() is called by emulate_single_step() which is called from (at least) alignment exception() handler and program_check_exception() handler. Redefine it as a regular __single_step_exception() which is called by both single_step_exception() handler and emulate_single_step() function. Fixes: 3a96570ffceb ("powerpc: convert interrupt handlers to use wrappers") Cc: stable@vger.kernel.org # v5.12+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/aed174f5cbc06f2cf95233c071d8aac948e46043.1628611921.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-18powerpc/interrupt: Fix OOPS by not calling do_IRQ() from timer_interrupt()Christophe Leroy4-3/+11
commit 98694166c27d473c36b434bd3572934c2f2a16ab upstream. An interrupt handler shall not be called from another interrupt handler otherwise this leads to problems like the following: Kernel attempted to write user page (afd4fa84) - exploit attempt? (uid: 1000) ------------[ cut here ]------------ Bug: Write fault blocked by KUAP! WARNING: CPU: 0 PID: 1617 at arch/powerpc/mm/fault.c:230 do_page_fault+0x484/0x720 Modules linked in: CPU: 0 PID: 1617 Comm: sshd Tainted: G W 5.13.0-pmac-00010-g8393422eb77 #7 NIP: c001b77c LR: c001b77c CTR: 00000000 REGS: cb9e5bc0 TRAP: 0700 Tainted: G W (5.13.0-pmac-00010-g8393422eb77) MSR: 00021032 <ME,IR,DR,RI> CR: 24942424 XER: 00000000 GPR00: c001b77c cb9e5c80 c1582c00 00000021 3ffffbff 085b0000 00000027 c8eb644c GPR08: 00000023 00000000 00000000 00000000 24942424 0063f8c8 00000000 000186a0 GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 c07640c4 cb9e5e98 cb9e5e90 GPR24: 00000040 afd4fa96 00000040 02000000 c1fda6c0 afd4fa84 00000300 cb9e5cc0 NIP [c001b77c] do_page_fault+0x484/0x720 LR [c001b77c] do_page_fault+0x484/0x720 Call Trace: [cb9e5c80] [c001b77c] do_page_fault+0x484/0x720 (unreliable) [cb9e5cb0] [c000424c] DataAccess_virt+0xd4/0xe4 --- interrupt: 300 at __copy_tofrom_user+0x110/0x20c NIP: c001f9b4 LR: c03250a0 CTR: 00000004 REGS: cb9e5cc0 TRAP: 0300 Tainted: G W (5.13.0-pmac-00010-g8393422eb77) MSR: 00009032 <EE,ME,IR,DR,RI> CR: 48028468 XER: 20000000 DAR: afd4fa84 DSISR: 0a000000 GPR00: 20726f6f cb9e5d80 c1582c00 00000004 cb9e5e3a 00000016 afd4fa80 00000000 GPR08: 3835202d 72777872 2d78722d 00000004 28028464 0063f8c8 00000000 000186a0 GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 c07640c4 cb9e5e98 cb9e5e90 GPR24: 00000040 afd4fa96 00000040 cb9e5e0c 00000daa a0000000 cb9e5e98 afd4fa56 NIP [c001f9b4] __copy_tofrom_user+0x110/0x20c LR [c03250a0] _copy_to_iter+0x144/0x990 --- interrupt: 300 [cb9e5d80] [c03e89c0] n_tty_read+0xa4/0x598 (unreliable) [cb9e5df0] [c03e2a0c] tty_read+0xdc/0x2b4 [cb9e5e80] [c0156bf8] vfs_read+0x274/0x340 [cb9e5f00] [c01571ac] ksys_read+0x70/0x118 [cb9e5f30] [c0016048] ret_from_syscall+0x0/0x28 --- interrupt: c00 at 0xa7855c88 NIP: a7855c88 LR: a7855c5c CTR: 00000000 REGS: cb9e5f40 TRAP: 0c00 Tainted: G W (5.13.0-pmac-00010-g8393422eb77) MSR: 0000d032 <EE,PR,ME,IR,DR,RI> CR: 2402446c XER: 00000000 GPR00: 00000003 afd4ec70 a72137d0 0000000b afd4ecac 00004000 0065a990 00000800 GPR08: 00000000 a7947930 00000000 00000004 c15831b0 0063f8c8 00000000 000186a0 GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 0065a9e0 00000001 0065fac0 GPR24: 00000000 00000089 00664050 00000000 00668e30 a720c8dc a7943ff4 0065f9b0 NIP [a7855c88] 0xa7855c88 LR [a7855c5c] 0xa7855c5c --- interrupt: c00 Instruction dump: 3884aa88 38630178 48076861 807f0080 48042e45 2f830000 419e0148 3c80c079 3c60c076 38841be4 386301c0 4801f705 <0fe00000> 3860000b 4bfffe30 3c80c06b ---[ end trace fd69b91a8046c2e5 ]--- Here the problem is that by re-enterring an exception handler, kuap_save_and_lock() is called a second time with this time KUAP access locked, leading to regs->kuap being overwritten hence KUAP not being unlocked at exception exit as expected. Do not call do_IRQ() from timer_interrupt() directly. Instead, redefine do_IRQ() as a standard function named __do_IRQ(), and call it from both do_IRQ() and time_interrupt() handlers. Fixes: 3a96570ffceb ("powerpc: convert interrupt handlers to use wrappers") Cc: stable@vger.kernel.org # v5.12+ Reported-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c17d234f4927d39a1d7100864a8e1145323d33a0.1628611927.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-18powerpc/kprobes: Fix kprobe Oops happens in bookePu Lehui1-1/+2
[ Upstream commit 43e8f76006592cb1573a959aa287c45421066f9c ] When using kprobe on powerpc booke series processor, Oops happens as show bellow: / # echo "p:myprobe do_nanosleep" > /sys/kernel/debug/tracing/kprobe_events / # echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable / # sleep 1 [ 50.076730] Oops: Exception in kernel mode, sig: 5 [#1] [ 50.077017] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500 [ 50.077221] Modules linked in: [ 50.077462] CPU: 0 PID: 77 Comm: sleep Not tainted 5.14.0-rc4-00022-g251a1524293d #21 [ 50.077887] NIP: c0b9c4e0 LR: c00ebecc CTR: 00000000 [ 50.078067] REGS: c3883de0 TRAP: 0700 Not tainted (5.14.0-rc4-00022-g251a1524293d) [ 50.078349] MSR: 00029000 <CE,EE,ME> CR: 24000228 XER: 20000000 [ 50.078675] [ 50.078675] GPR00: c00ebdf0 c3883e90 c313e300 c3883ea0 00000001 00000000 c3883ecc 00000001 [ 50.078675] GPR08: c100598c c00ea250 00000004 00000000 24000222 102490c2 bff4180c 101e60d4 [ 50.078675] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f8 10240000 00500000 [ 50.078675] GPR24: 00000002 00000000 c3883ea0 00000001 00000000 0000c350 3b9b8d50 00000000 [ 50.080151] NIP [c0b9c4e0] do_nanosleep+0x0/0x190 [ 50.080352] LR [c00ebecc] hrtimer_nanosleep+0x14c/0x1e0 [ 50.080638] Call Trace: [ 50.080801] [c3883e90] [c00ebdf0] hrtimer_nanosleep+0x70/0x1e0 (unreliable) [ 50.081110] [c3883f00] [c00ec004] sys_nanosleep_time32+0xa4/0x110 [ 50.081336] [c3883f40] [c001509c] ret_from_syscall+0x0/0x28 [ 50.081541] --- interrupt: c00 at 0x100a4d08 [ 50.081749] NIP: 100a4d08 LR: 101b5234 CTR: 00000003 [ 50.081931] REGS: c3883f50 TRAP: 0c00 Not tainted (5.14.0-rc4-00022-g251a1524293d) [ 50.082183] MSR: 0002f902 <CE,EE,PR,FP,ME> CR: 24000222 XER: 00000000 [ 50.082457] [ 50.082457] GPR00: 000000a2 bf980040 1024b4d0 bf980084 bf980084 64000000 00555345 fefefeff [ 50.082457] GPR08: 7f7f7f7f 101e0000 00000069 00000003 28000422 102490c2 bff4180c 101e60d4 [ 50.082457] GPR16: 00000000 102454ac 00000040 10240000 10241100 102410f8 10240000 00500000 [ 50.082457] GPR24: 00000002 bf9803f4 10240000 00000000 00000000 100039e0 00000000 102444e8 [ 50.083789] NIP [100a4d08] 0x100a4d08 [ 50.083917] LR [101b5234] 0x101b5234 [ 50.084042] --- interrupt: c00 [ 50.084238] Instruction dump: [ 50.084483] 4bfffc40 60000000 60000000 60000000 9421fff0 39400402 914200c0 38210010 [ 50.084841] 4bfffc20 00000000 00000000 00000000 <7fe00008> 7c0802a6 7c892378 93c10048 [ 50.085487] ---[ end trace f6fffe98e2fa8f3e ]--- [ 50.085678] Trace/breakpoint trap There is no real mode for booke arch and the MMU translation is always on. The corresponding MSR_IS/MSR_DS bit in booke is used to switch the address space, but not for real mode judgment. Fixes: 21f8b2fa3ca5 ("powerpc/kprobes: Ignore traps that happened in real mode") Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210809023658.218915-1-pulehui@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-04powerpc/pseries: Fix regression while building external modulesSrikar Dronamraju1-1/+1
commit 333cf507465fbebb3727f5b53e77538467df312a upstream. With commit c9f3401313a5 ("powerpc: Always enable queued spinlocks for 64s, disable for others") CONFIG_PPC_QUEUED_SPINLOCKS is always enabled on ppc64le, external modules that use spinlock APIs are failing. ERROR: modpost: GPL-incompatible module XXX.ko uses GPL-only symbol 'shared_processor' Before the above commit, modules were able to build without any issues. Also this problem is not seen on other architectures. This problem can be workaround if CONFIG_UNINLINE_SPIN_UNLOCK is enabled in the config. However CONFIG_UNINLINE_SPIN_UNLOCK is not enabled by default and only enabled in certain conditions like CONFIG_DEBUG_SPINLOCKS is set in the kernel config. #include <linux/module.h> spinlock_t spLock; static int __init spinlock_test_init(void) { spin_lock_init(&spLock); spin_lock(&spLock); spin_unlock(&spLock); return 0; } static void __exit spinlock_test_exit(void) { printk("spinlock_test unloaded\n"); } module_init(spinlock_test_init); module_exit(spinlock_test_exit); MODULE_DESCRIPTION ("spinlock_test"); MODULE_LICENSE ("non-GPL"); MODULE_AUTHOR ("Srikar Dronamraju"); Given that spin locks are one of the basic facilities for module code, this effectively makes it impossible to build/load almost any non GPL modules on ppc64le. This was first reported at https://github.com/openzfs/zfs/issues/11172 Currently shared_processor is exported as GPL only symbol. Fix this for parity with other architectures by exposing shared_processor to non-GPL modules too. Fixes: 14c73bd344da ("powerpc/vcpu: Assume dedicated processors as non-preempt") Cc: stable@vger.kernel.org # v5.5+ Reported-by: marc.c.dionne@gmail.com Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210729060449.292780-1-srikar@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-04powerpc/vdso: Don't use r30 to avoid breaking Go langMichael Ellerman1-0/+7
commit a88603f4b92ecef9e2359e40bcb99ad399d85dd7 upstream. The Go runtime uses r30 for some special value called 'g'. It assumes that value will remain unchanged even when calling VDSO functions. Although r30 is non-volatile across function calls, the callee is free to use it, as long as the callee saves the value and restores it before returning. It used to be true by accident that the VDSO didn't use r30, because the VDSO was hand-written asm. When we switched to building the VDSO from C the compiler started using r30, at least in some builds, leading to crashes in Go. eg: ~/go/src$ ./all.bash Building Go cmd/dist using /usr/lib/go-1.16. (go1.16.2 linux/ppc64le) Building Go toolchain1 using /usr/lib/go-1.16. go build os/exec: /usr/lib/go-1.16/pkg/tool/linux_ppc64le/compile: signal: segmentation fault go build reflect: /usr/lib/go-1.16/pkg/tool/linux_ppc64le/compile: signal: segmentation fault go tool dist: FAILED: /usr/lib/go-1.16/bin/go install -gcflags=-l -tags=math_big_pure_go compiler_bootstrap bootstrap/cmd/...: exit status 1 There are patches in flight to fix Go[1], but until they are released and widely deployed we can workaround it in the VDSO by avoiding use of r30. Note this only works with GCC, clang does not support -ffixed-rN. 1: https://go-review.googlesource.com/c/go/+/328110 Fixes: ab037dd87a2f ("powerpc/vdso: Switch VDSO to generic C implementation.") Cc: stable@vger.kernel.org # v5.11+ Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> Tested-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210729131244.2595519-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-04bpf: Introduce BPF nospec instruction for mitigating Spectre v4Daniel Borkmann2-0/+12
[ Upstream commit f5e81d1117501546b7be050c5fbafa6efd2c722c ] In case of JITs, each of the JIT backends compiles the BPF nospec instruction /either/ to a machine instruction which emits a speculation barrier /or/ to /no/ machine instruction in case the underlying architecture is not affected by Speculative Store Bypass or has different mitigations in place already. This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence' instruction for mitigation. In case of arm64, we rely on the firmware mitigation as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled, it works for all of the kernel code with no need to provide any additional instructions here (hence only comment in arm64 JIT). Other archs can follow as needed. The BPF nospec instruction is specifically targeting Spectre v4 since i) we don't use a serialization barrier for the Spectre v1 case, and ii) mitigation instructions for v1 and v4 might be different on some archs. The BPF nospec is required for a future commit, where the BPF verifier does annotate intermediate BPF programs with speculation barriers. Co-developed-by: Piotr Krysiuk <piotras@gmail.com> Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Piotr Krysiuk <piotras@gmail.com> Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28KVM: PPC: Book3S HV Nested: Sanitise H_ENTER_NESTED TM stateNicholas Piggin1-0/+20
commit d9c57d3ed52a92536f5fa59dc5ccdd58b4875076 upstream. The H_ENTER_NESTED hypercall is handled by the L0, and it is a request by the L1 to switch the context of the vCPU over to that of its L2 guest, and return with an interrupt indication. The L1 is responsible for switching some registers to guest context, and the L0 switches others (including all the hypervisor privileged state). If the L2 MSR has TM active, then the L1 is responsible for recheckpointing the L2 TM state. Then the L1 exits to L0 via the H_ENTER_NESTED hcall, and the L0 saves the TM state as part of the exit, and then it recheckpoints the TM state as part of the nested entry and finally HRFIDs into the L2 with TM active MSR. Not efficient, but about the simplest approach for something that's horrendously complicated. Problems arise if the L1 exits to the L0 with a TM state which does not match the L2 TM state being requested. For example if the L1 is transactional but the L2 MSR is non-transactional, or vice versa. The L0's HRFID can take a TM Bad Thing interrupt and crash. Fix this by disallowing H_ENTER_NESTED in TM[T] state entirely, and then ensuring that if the L1 is suspended then the L2 must have TM active, and if the L1 is not suspended then the L2 must not have TM active. Fixes: 360cae313702 ("KVM: PPC: Book3S HV: Nested guest entry via hypercall") Cc: stable@vger.kernel.org # v4.20+ Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28KVM: PPC: Book3S: Fix H_RTAS rets buffer overflowNicholas Piggin1-3/+22
commit f62f3c20647ebd5fb6ecb8f0b477b9281c44c10a upstream. The kvmppc_rtas_hcall() sets the host rtas_args.rets pointer based on the rtas_args.nargs that was provided by the guest. That guest nargs value is not range checked, so the guest can cause the host rets pointer to be pointed outside the args array. The individual rtas function handlers check the nargs and nrets values to ensure they are correct, but if they are not, the handlers store a -3 (0xfffffffd) failure indication in rets[0] which corrupts host memory. Fix this by testing up front whether the guest supplied nargs and nret would exceed the array size, and fail the hcall directly without storing a failure indication to rets[0]. Also expand on a comment about why we kill the guest and try not to return errors directly if we have a valid rets[0] pointer. Fixes: 8e591cb72047 ("KVM: PPC: Book3S: Add infrastructure to implement kernel-side RTAS calls") Cc: stable@vger.kernel.org # v3.10+ Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28KVM: PPC: Fix kvm_arch_vcpu_ioctl vcpu_load leakNicholas Piggin1-2/+2
[ Upstream commit bc4188a2f56e821ea057aca6bf444e138d06c252 ] vcpu_put is not called if the user copy fails. This can result in preempt notifier corruption and crashes, among other issues. Fixes: b3cebfe8c1ca ("KVM: PPC: Move vcpu_load/vcpu_put down to each ioctl case in kvm_arch_vcpu_ioctl") Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210716024310.164448-2-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28KVM: PPC: Book3S: Fix CONFIG_TRANSACTIONAL_MEM=n crashNicholas Piggin1-0/+2
[ Upstream commit bd31ecf44b8e18ccb1e5f6b50f85de6922a60de3 ] When running CPU_FTR_P9_TM_HV_ASSIST, HFSCR[TM] is set for the guest even if the host has CONFIG_TRANSACTIONAL_MEM=n, which causes it to be unprepared to handle guest exits while transactional. Normal guests don't have a problem because the HTM capability will not be advertised, but a rogue or buggy one could crash the host. Fixes: 4bb3c7a0208f ("KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9") Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210716024310.164448-1-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20powerpc/bpf: Fix detecting BPF atomic instructionsNaveen N. Rao1-2/+2
[ Upstream commit 419ac821766cbdb9fd85872bb3f1a589df05c94c ] Commit 91c960b0056672 ("bpf: Rename BPF_XADD and prepare to encode other atomics in .imm") converted BPF_XADD to BPF_ATOMIC and added a way to distinguish instructions based on the immediate field. Existing JIT implementations were updated to check for the immediate field and to reject programs utilizing anything more than BPF_ADD (such as BPF_FETCH) in the immediate field. However, the check added to powerpc64 JIT did not look at the correct BPF instruction. Due to this, such programs would be accepted and incorrectly JIT'ed resulting in soft lockups, as seen with the atomic bounds test. Fix this by looking at the correct immediate value. Fixes: 91c960b0056672 ("bpf: Rename BPF_XADD and prepare to encode other atomics in .imm") Reported-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Tested-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4117b430ffaa8cd7af042496f87fd7539e4f17fd.1625145429.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20powerpc/boot: Fixup device-tree on little endianBenjamin Herrenschmidt2-27/+41
[ Upstream commit c93f80849bdd9b45d834053ae1336e28f0026c84 ] This fixes the core devtree.c functions and the ns16550 UART backend. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org> Acked-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/YMwXrPT8nc4YUdJ9@thinks.paulus.ozlabs.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20powerpc/mm/book3s64: Fix possible build errorAneesh Kumar K.V1-9/+17
[ Upstream commit 07d8ad6fd8a3d47f50595ca4826f41dbf4f3a0c6 ] Update _tlbiel_pid() such that we can avoid build errors like below when using this function in other places. arch/powerpc/mm/book3s64/radix_tlb.c: In function ‘__radix__flush_tlb_range_psize’: arch/powerpc/mm/book3s64/radix_tlb.c:114:2: warning: ‘asm’ operand 3 probably does not match constraints 114 | asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1) | ^~~ arch/powerpc/mm/book3s64/radix_tlb.c:114:2: error: impossible constraint in ‘asm’ make[4]: *** [scripts/Makefile.build:271: arch/powerpc/mm/book3s64/radix_tlb.o] Error 1 m With this fix, we can also drop the __always_inline in __radix_flush_tlb_range_psize which was added by commit e12d6d7d46a6 ("powerpc/mm/radix: mark __radix__flush_tlb_range_psize() as __always_inline") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210610083639.387365-1-aneesh.kumar@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20powerpc/inst: Fix sparse detection on get_user_instr()Christophe Leroy1-1/+6
[ Upstream commit b3a9e523237013477bea914b7fbfbe420428b988 ] get_user_instr() lacks sparse detection for the __user tag. This is because __gui_ptr is assigned with a cast. Fix that by adding a __chk_user_ptr() Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0320e5b41a794fd456ab8c5993bbfadcf9e1d8b4.1621516826.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20powerpc/ps3: Add dma_mask to ps3_dma_regionGeoff Levand2-0/+14
[ Upstream commit 9733862e50fdba55e7f1554e4286fcc5302ff28e ] Commit f959dcd6ddfd29235030e8026471ac1b022ad2b0 (dma-direct: Fix potential NULL pointer dereference) added a null check on the dma_mask pointer of the kernel's device structure. Add a dma_mask variable to the ps3_dma_region structure and set the device structure's dma_mask pointer to point to this new variable. Fixes runtime errors like these: # WARNING: Fixes tag on line 10 doesn't match correct format # WARNING: Fixes tag on line 10 doesn't match correct format ps3_system_bus_match:349: dev=8.0(sb_01), drv=8.0(ps3flash): match WARNING: CPU: 0 PID: 1 at kernel/dma/mapping.c:151 .dma_map_page_attrs+0x34/0x1e0 ps3flash sb_01: ps3stor_setup:193: map DMA region failed Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/562d0c9ea0100a30c3b186bcc7adb34b0bbd2cd7.1622746428.git.geoff@infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19powerpc/powernv/vas: Release reference to tgid during window closeHaren Myneni1-4/+5
commit 91cdbb955aa94ee0841af4685be40937345d29b8 upstream. The kernel handles the NX fault by updating CSB or sending signal to process. In multithread applications, children can open VAS windows and can exit without closing them. But the parent can continue to send NX requests with these windows. To prevent pid reuse, reference will be taken on pid and tgid when the window is opened and release them during window close. The current code is not releasing the tgid reference which can cause pid leak and this patch fixes the issue. Fixes: db1c08a740635 ("powerpc/vas: Take reference to PID and mm for user space windows") Cc: stable@vger.kernel.org # 5.8+ Reported-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6020fc4d444864fe20f7dcdc5edfe53e67480a1c.camel@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-19powerpc/barrier: Avoid collision with clang's __lwsync macroNathan Chancellor1-0/+2
commit 015d98149b326e0f1f02e44413112ca8b4330543 upstream. A change in clang 13 results in the __lwsync macro being defined as __builtin_ppc_lwsync, which emits 'lwsync' or 'msync' depending on what the target supports. This breaks the build because of -Werror in arch/powerpc, along with thousands of warnings: In file included from arch/powerpc/kernel/pmc.c:12: In file included from include/linux/bug.h:5: In file included from arch/powerpc/include/asm/bug.h:109: In file included from include/asm-generic/bug.h:20: In file included from include/linux/kernel.h:12: In file included from include/linux/bitops.h:32: In file included from arch/powerpc/include/asm/bitops.h:62: arch/powerpc/include/asm/barrier.h:49:9: error: '__lwsync' macro redefined [-Werror,-Wmacro-redefined] #define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") ^ <built-in>:308:9: note: previous definition is here #define __lwsync __builtin_ppc_lwsync ^ 1 error generated. Undefine this macro so that the runtime patching introduced by commit 2d1b2027626d ("powerpc: Fixup lwsync at runtime") continues to work properly with clang and the build no longer breaks. Cc: stable@vger.kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://github.com/ClangBuiltLinux/linux/issues/1386 Link: https://github.com/llvm/llvm-project/commit/62b5df7fe2b3fda1772befeda15598fbef96a614 Link: https://lore.kernel.org/r/20210528182752.1852002-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-19powerpc/xive: Fix error handling when allocating an IPICédric Le Goater1-4/+3
commit 3f601608b71c3ca1e199898cd16f09d707fedb56 upstream. This is a smatch warning: arch/powerpc/sysdev/xive/common.c:1161 xive_request_ipi() warn: unsigned 'xid->irq' is never less than zero. Fixes: fd6db2892eba ("powerpc/xive: Modernize XIVE-IPI domain with an 'alloc' handler") Cc: stable@vger.kernel.org # v5.13 Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210701152412.1507612-1-clg@kaod.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-19powerpc/bpf: Reject atomic ops in ppc32 JITNaveen N. Rao1-3/+11
commit 307e5042c7bdae15308ef2e9b848833b84122eb0 upstream. Commit 91c960b0056672 ("bpf: Rename BPF_XADD and prepare to encode other atomics in .imm") converted BPF_XADD to BPF_ATOMIC and updated all JIT implementations to reject JIT'ing instructions with an immediate value different from BPF_ADD. However, ppc32 BPF JIT was implemented around the same time and didn't include the same change. Update the ppc32 JIT accordingly. Fixes: 51c66ad849a7 ("powerpc/bpf: Implement extended BPF on PPC32") Cc: stable@vger.kernel.org # v5.13+ Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/426699046d89fe50f66ecf74bd31c01eda976ba5.1625145429.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-19powerpc/mm: Fix lockup on kernel exec faultChristophe Leroy1-3/+1
commit cd5d5e602f502895e47e18cd46804d6d7014e65c upstream. The powerpc kernel is not prepared to handle exec faults from kernel. Especially, the function is_exec_fault() will return 'false' when an exec fault is taken by kernel, because the check is based on reading current->thread.regs->trap which contains the trap from user. For instance, when provoking a LKDTM EXEC_USERSPACE test, current->thread.regs->trap is set to SYSCALL trap (0xc00), and the fault taken by the kernel is not seen as an exec fault by set_access_flags_filter(). Commit d7df2443cd5f ("powerpc/mm: Fix spurious segfaults on radix with autonuma") made it clear and handled it properly. But later on commit d3ca587404b3 ("powerpc/mm: Fix reporting of kernel execute faults") removed that handling, introducing test based on error_code. And here is the problem, because on the 603 all upper bits of SRR1 get cleared when the TLB instruction miss handler bails out to ISI. Until commit cbd7e6ca0210 ("powerpc/fault: Avoid heavy search_exception_tables() verification"), an exec fault from kernel at a userspace address was indirectly caught by the lack of entry for that address in the exception tables. But after that commit the kernel mainly relies on KUAP or on core mm handling to catch wrong user accesses. Here the access is not wrong, so mm handles it. It is a minor fault because PAGE_EXEC is not set, set_access_flags_filter() should set PAGE_EXEC and voila. But as is_exec_fault() returns false as explained in the beginning, set_access_flags_filter() bails out without setting PAGE_EXEC flag, which leads to a forever minor exec fault. As the kernel is not prepared to handle such exec faults, the thing to do is to fire in bad_kernel_fault() for any exec fault taken by the kernel, as it was prior to commit d3ca587404b3. Fixes: d3ca587404b3 ("powerpc/mm: Fix reporting of kernel execute faults") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/024bb05105050f704743a0083fe3548702be5706.1625138205.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-14powerpc/preempt: Don't touch the idle task's preempt_count during hotplugValentin Schneider2-6/+0
commit 2c669ef6979c370f98d4b876e54f19613c81e075 upstream. Powerpc currently resets a CPU's idle task preempt_count to 0 before said task starts executing the secondary startup routine (and becomes an idle task proper). This conflicts with commit f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled"). which initializes all of the idle tasks' preempt_count to PREEMPT_DISABLED during smp_init(). Note that this was superfluous before said commit, as back then the hotplug machinery would invoke init_idle() via idle_thread_get(), which would have already reset the CPU's idle task's preempt_count to PREEMPT_ENABLED. Get rid of this preempt_count write. Fixes: f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled") Reported-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210707183831.2106509-1-valentin.schneider@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-14powerpc/64s/interrupt: preserve regs->softe for NMI interruptsNicholas Piggin1-0/+3
[ Upstream commit 1b0482229c302a3c6afd00d6b3bf0169cf279b44 ] If an NMI interrupt hits in an implicit soft-masked region, regs->softe is modified to reflect that. This may not be necessary for correctness at the moment, but it is less surprising and it's unhelpful when debugging or adding checks. Make sure this is changed back to how it was found before returning. Fixes: 4ec5feec1ad0 ("powerpc/64s: Make NMI record implicitly soft-masked code as irqs disabled") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210630074621.2109197-6-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14powerpc/64s: fix hash page fault interrupt handlerNicholas Piggin1-13/+11
[ Upstream commit 5567b1ee29b7a83e8c01d99d34b5bbd306ce0bcf ] The early bad fault or key fault test in do_hash_fault() ends up calling into ___do_page_fault without having gone through an interrupt handler wrapper (except the initial _RAW one). This can end up calling local irq functions while the interrupt has not been reconciled, which will likely cause crashes and it trips up on a later patch that adds more assertions. pkey_exec_prot from selftests causes this path to be executed. There is no real reason to run the in_nmi() test should be performed before the key fault check. In fact if a perf interrupt in the hash fault code did a stack walk that was made to take a key fault somehow then running ___do_page_fault could possibly cause another hash fault causing problems. Move the in_nmi() test first, and then do everything else inside the regular interrupt handler function. Fixes: 3a96570ffceb ("powerpc: convert interrupt handlers to use wrappers") Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210630074621.2109197-2-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14powerpc: Fix is_kvm_guest() / kvm_para_available()Michael Ellerman3-7/+11
[ Upstream commit 95839225639ba7c3d8d7231b542728dcf222bf2d ] Commit a21d1becaa3f ("powerpc: Reintroduce is_kvm_guest() as a fast-path check") added is_kvm_guest() and changed kvm_para_available() to use it. is_kvm_guest() checks a static key, kvm_guest, and that static key is set in check_kvm_guest(). The problem is check_kvm_guest() is only called on pseries, and even then only in some configurations. That means is_kvm_guest() always returns false on all non-pseries and some pseries depending on configuration. That's a bug. For PR KVM guests this is noticable because they no longer do live patching of themselves, which can be detected by the omission of a message in dmesg such as: KVM: Live patching for a fast VM worked To fix it make check_kvm_guest() an initcall, to ensure it's always called at boot. It needs to be core so that it runs before kvm_guest_init() which is postcore. To be an initcall it needs to return int, where 0 means success, so update that. We still call it manually in pSeries_smp_probe(), because that runs before init calls are run. Fixes: a21d1becaa3f ("powerpc: Reintroduce is_kvm_guest() as a fast-path check") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210623130514.2543232-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14powerpc/papr_scm: Make 'perf_stats' invisible if perf-stats unavailableVaibhav Jain1-11/+24
[ Upstream commit ed78f56e1271f108e8af61baeba383dcd77adbec ] In case performance stats for an nvdimm are not available, reading the 'perf_stats' sysfs file returns an -ENOENT error. A better approach is to make the 'perf_stats' file entirely invisible to indicate that performance stats for an nvdimm are unavailable. So this patch updates 'papr_nd_attribute_group' to add a 'is_visible' callback implemented as newly introduced 'papr_nd_attribute_visible()' that returns an appropriate mode in case performance stats aren't supported in a given nvdimm. Also the initialization of 'papr_scm_priv.stat_buffer_len' is moved from papr_scm_nvdimm_init() to papr_scm_probe() so that it value is available when 'papr_nd_attribute_visible()' is called during nvdimm initialization. Even though 'perf_stats' attribute is available since v5.9, there are no known user-space tools/scripts that are dependent on presence of its sysfs file. Hence I dont expect any user-space breakage with this patch. Fixes: 2d02bf835e57 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP") Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210513092349.285021-1-vaibhav@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14powerpc/64s: Fix copy-paste data exposure into newly created tasksNicholas Piggin1-16/+32
[ Upstream commit f35d2f249ef05b9671e7898f09ad89aa78f99122 ] copy-paste contains implicit "copy buffer" state that can contain arbitrary user data (if the user process executes a copy instruction). This could be snooped by another process if a context switch hits while the state is live. So cp_abort is executed on context switch to clear out possible sensitive data and prevent the leak. cp_abort is done after the low level _switch(), which means it is never reached by newly created tasks, so they could snoop on this buffer between their first and second context switch. Fix this by doing the cp_abort before calling _switch. Add some comments which should make the issue harder to miss. Fixes: 07d2a628bc000 ("powerpc/64s: Avoid cpabort in context switch when possible") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210622053036.474678-1-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14powerpc/papr_scm: Properly handle UUID types and APIAndy Shevchenko1-9/+18
[ Upstream commit 0e8554b5d7801b0aebc6c348a0a9f7706aa17b3b ] Parse to and export from UUID own type, before dereferencing. This also fixes wrong comment (Little Endian UUID is something else) and should eliminate the direct strict types assignments. Fixes: 43001c52b603 ("powerpc/papr_scm: Use ibm,unit-guid as the iset cookie") Fixes: 259a948c4ba1 ("powerpc/pseries/scm: Use a specific endian format for storing uuid from the device tree") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210616134303.58185-1-andriy.shevchenko@linux.intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14powerpc: Offline CPU in stop_this_cpu()Nicholas Piggin1-0/+11
[ Upstream commit bab26238bbd44d5a4687c0a64fd2c7f2755ea937 ] printk_safe_flush_on_panic() has special lock breaking code for the case where we panic()ed with the console lock held. It relies on panic IPI causing other CPUs to mark themselves offline. Do as most other architectures do. This effectively reverts commit de6e5d38417e ("powerpc: smp_send_stop do not offline stopped CPUs"), unfortunately it may result in some false positive warnings, but the alternative is more situations where we can crash without getting messages out. Fixes: de6e5d38417e ("powerpc: smp_send_stop do not offline stopped CPUs") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210623041245.865134-1-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14powerpc/powernv: Fix machine check reporting of async store errorsNicholas Piggin1-8/+40
[ Upstream commit 3729e0ec59a20825bd4c8c70996b2df63915e1dd ] POWER9 and POWER10 asynchronous machine checks due to stores have their cause reported in SRR1 but SRR1[42] is set, which in other cases indicates DSISR cause. Check for these cases and clear SRR1[42], so the cause matching uses the i-side (SRR1) table. Fixes: 7b9f71f974a1 ("powerpc/64s: POWER9 machine check handler") Fixes: 201220bb0e8c ("powerpc/powernv: Machine check handler for POWER10") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210517140355.2325406-1-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14KVM: PPC: Book3S HV: Fix TLB management on SMT8 POWER9 and POWER10 processorsSuraj Jitindar Singh4-8/+39
[ Upstream commit 77bbbc0cf84834ed130838f7ac1988567f4d0288 ] The POWER9 vCPU TLB management code assumes all threads in a core share a TLB, and that TLBIEL execued by one thread will invalidate TLBs for all threads. This is not the case for SMT8 capable POWER9 and POWER10 (big core) processors, where the TLB is split between groups of threads. This results in TLB multi-hits, random data corruption, etc. Fix this by introducing cpu_first_tlb_thread_sibling etc., to determine which siblings share TLBs, and use that in the guest TLB flushing code. [npiggin@gmail.com: add changelog and comment] Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210602040441.3984352-1-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14sched/core: Initialize the idle task with preemption disabledValentin Schneider1-1/+0
[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ] As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14powerpc/stacktrace: Fix spurious "stale" traces in raise_backtrace_ipi()Michael Ellerman1-6/+20
commit 7c6986ade69e3c81bac831645bc72109cd798a80 upstream. In raise_backtrace_ipi() we iterate through the cpumask of CPUs, sending each an IPI asking them to do a backtrace, but we don't wait for the backtrace to happen. We then iterate through the CPU mask again, and if any CPU hasn't done the backtrace and cleared itself from the mask, we print a trace on its behalf, noting that the trace may be "stale". This works well enough when a CPU is not responding, because in that case it doesn't receive the IPI and the sending CPU is left to print the trace. But when all CPUs are responding we are left with a race between the sending and receiving CPUs, if the sending CPU wins the race then it will erroneously print a trace. This leads to spurious "stale" traces from the sending CPU, which can then be interleaved messily with the receiving CPU, note the CPU numbers, eg: [ 1658.929157][ C7] rcu: Stack dump where RCU GP kthread last ran: [ 1658.929223][ C7] Sending NMI from CPU 7 to CPUs 1: [ 1658.929303][ C1] NMI backtrace for cpu 1 [ 1658.929303][ C7] CPU 1 didn't respond to backtrace IPI, inspecting paca. [ 1658.929362][ C1] CPU: 1 PID: 325 Comm: kworker/1:1H Tainted: G W E 5.13.0-rc2+ #46 [ 1658.929405][ C7] irq_soft_mask: 0x01 in_mce: 0 in_nmi: 0 current: 325 (kworker/1:1H) [ 1658.929465][ C1] Workqueue: events_highpri test_work_fn [test_lockup] [ 1658.929549][ C7] Back trace of paca->saved_r1 (0xc0000000057fb400) (possibly stale): [ 1658.929592][ C1] NIP: c00000000002cf50 LR: c008000000820178 CTR: c00000000002cfa0 To fix it, change the logic so that the sending CPU waits 5s for the receiving CPU to print its trace. If the receiving CPU prints its trace successfully then the sending CPU just continues, avoiding any spurious "stale" trace. This has the added benefit of allowing all CPUs to print their traces in order and avoids any interleaving of their output. Fixes: 5cc05910f26e ("powerpc/64s: Wire up arch_trigger_cpumask_backtrace()") Cc: stable@vger.kernel.org # v4.18+ Reported-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210625140408.3351173-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-14KVM: PPC: Book3S HV: Workaround high stack usage with clangNathan Chancellor1-1/+2
commit 51696f39cbee5bb684e7959c0c98b5f54548aa34 upstream. LLVM does not emit optimal byteswap assembly, which results in high stack usage in kvmhv_enter_nested_guest() due to the inlining of byteswap_pt_regs(). With LLVM 12.0.0: arch/powerpc/kvm/book3s_hv_nested.c:289:6: error: stack frame size of 2512 bytes in function 'kvmhv_enter_nested_guest' [-Werror,-Wframe-larger-than=] long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu) ^ 1 error generated. While this gets fixed in LLVM, mark byteswap_pt_regs() as noinline_for_stack so that it does not get inlined and break the build due to -Werror by default in arch/powerpc/. Not inlining saves approximately 800 bytes with LLVM 12.0.0: arch/powerpc/kvm/book3s_hv_nested.c:290:6: warning: stack frame size of 1728 bytes in function 'kvmhv_enter_nested_guest' [-Wframe-larger-than=] long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu) ^ 1 warning generated. Cc: stable@vger.kernel.org # v4.20+ Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://github.com/ClangBuiltLinux/linux/issues/1292 Link: https://bugs.llvm.org/show_bug.cgi?id=49610 Link: https://lore.kernel.org/r/202104031853.vDT0Qjqj-lkp@intel.com/ Link: https://gist.github.com/ba710e3703bf45043a31e2806c843ffd Link: https://lore.kernel.org/r/20210621182440.990242-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-20Merge tag 'powerpc-5.13-6' of ↵Linus Torvalds4-7/+7
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Fix initrd corruption caused by our recent change to use relative jump labels. Fix a crash using perf record on systems without a hardware PMU backend. Rework our 64-bit signal handling slighty to make it more closely match the old behaviour, after the recent change to use unsafe user accessors. Thanks to Anastasia Kovaleva, Athira Rajeev, Christophe Leroy, Daniel Axtens, Greg Kurz, and Roman Bolshakov" * tag 'powerpc-5.13-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/perf: Fix crash in perf_instruction_pointer() when ppmu is not set powerpc: Fix initrd corruption with relative jump labels powerpc/signal64: Copy siginfo before changing regs->nip powerpc/mem: Add back missing header to fix 'no previous prototype' error
2021-06-18powerpc/perf: Fix crash in perf_instruction_pointer() when ppmu is not setAthira Rajeev1-1/+1
On systems without any specific PMU driver support registered, running perf record causes Oops. The relevant portion from call trace: BUG: Kernel NULL pointer dereference on read at 0x00000040 Faulting instruction address: 0xc0021f0c Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=4K PREEMPT CMPCPRO SAF3000 DIE NOTIFICATION CPU: 0 PID: 442 Comm: null_syscall Not tainted 5.13.0-rc6-s3k-dev-01645-g7649ee3d2957 #5164 NIP: c0021f0c LR: c00e8ad8 CTR: c00d8a5c NIP perf_instruction_pointer+0x10/0x60 LR perf_prepare_sample+0x344/0x674 Call Trace: perf_prepare_sample+0x7c/0x674 (unreliable) perf_event_output_forward+0x3c/0x94 __perf_event_overflow+0x74/0x14c perf_swevent_hrtimer+0xf8/0x170 __hrtimer_run_queues.constprop.0+0x160/0x318 hrtimer_interrupt+0x148/0x3b0 timer_interrupt+0xc4/0x22c Decrementer_virt+0xb8/0xbc During perf record session, perf_instruction_pointer() is called to capture the sample IP. This function in core-book3s accesses ppmu->flags. If a platform specific PMU driver is not registered, ppmu is set to NULL and accessing its members results in a crash. Fix this crash by checking if ppmu is set. Fixes: 2ca13a4cc56c ("powerpc/perf: Use regs->nip when SIAR is zero") Cc: stable@vger.kernel.org # v5.11+ Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1623952506-1431-1-git-send-email-atrajeev@linux.vnet.ibm.com
2021-06-15powerpc: Fix initrd corruption with relative jump labelsMichael Ellerman1-1/+1
Commit b0b3b2c78ec0 ("powerpc: Switch to relative jump labels") switched us to using relative jump labels. That involves changing the code, target and key members in struct jump_entry to be relative to the address of the jump_entry, rather than absolute addresses. We have two static inlines that create a struct jump_entry, arch_static_branch() and arch_static_branch_jump(), as well as an asm macro ARCH_STATIC_BRANCH, which is used by the pseries-only hypervisor tracing code. Unfortunately we missed updating the key to be a relative reference in ARCH_STATIC_BRANCH. That causes a pseries kernel to have a handful of jump_entry structs with bad key values. Instead of being a relative reference they instead hold the full address of the key. However the code doesn't expect that, it still adds the key value to the address of the jump_entry (see jump_entry_key()) expecting to get a pointer to a key somewhere in kernel data. The table of jump_entry structs sits in rodata, which comes after the kernel text. In a typical build this will be somewhere around 15MB. The address of the key will be somewhere in data, typically around 20MB. Adding the two values together gets us a pointer somewhere around 45MB. We then call static_key_set_entries() with that bad pointer and modify some members of the struct static_key we think we are pointing at. A pseries kernel is typically ~30MB in size, so writing to ~45MB won't corrupt the kernel itself. However if we're booting with an initrd, depending on the size and exact location of the initrd, we can corrupt the initrd. Depending on how exactly we corrupt the initrd it can either cause the system to not boot, or just corrupt one of the files in the initrd. The fix is simply to make the key value relative to the jump_entry struct in the ARCH_STATIC_BRANCH macro. Fixes: b0b3b2c78ec0 ("powerpc: Switch to relative jump labels") Reported-by: Anastasia Kovaleva <a.kovaleva@yadro.com> Reported-by: Roman Bolshakov <r.bolshakov@yadro.com> Reported-by: Greg Kurz <groug@kaod.org> Reported-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Daniel Axtens <dja@axtens.net> Tested-by: Greg Kurz <groug@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210614131440.312360-1-mpe@ellerman.id.au
2021-06-14powerpc/signal64: Copy siginfo before changing regs->nipMichael Ellerman1-5/+4
In commit 96d7a4e06fab ("powerpc/signal64: Rewrite handle_rt_signal64() to minimise uaccess switches") the 64-bit signal code was rearranged to use user_write_access_begin/end(). As part of that change the call to copy_siginfo_to_user() was moved later in the function, so that it could be done after the user_write_access_end(). In particular it was moved after we modify regs->nip to point to the signal trampoline. That means if copy_siginfo_to_user() fails we exit handle_rt_signal64() with an error but with regs->nip modified, whereas previously we would not modify regs->nip until the copy succeeded. Returning an error from signal delivery but with regs->nip updated leaves the process in a sort of half-delivered state. We do immediately force a SEGV in signal_setup_done(), called from do_signal(), so the process should never run in the half-delivered state. However that SEGV is not delivered until we've gone around to do_notify_resume() again, so it's possible some tracing could observe the half-delivered state. There are other cases where we fail signal delivery with regs partly updated, eg. the write to newsp and SA_SIGINFO, but the latter at least is very unlikely to fail as it reads back from the frame we just wrote to. Looking at other arches they seem to be more careful about leaving regs unchanged until the copy operations have succeeded, and in general that seems like good hygenie. So although the current behaviour is not cleary buggy, it's also not clearly correct. So move the call to copy_siginfo_to_user() up prior to the modification of regs->nip, which is closer to the old behaviour, and easier to reason about. Fixes: 96d7a4e06fab ("powerpc/signal64: Rewrite handle_rt_signal64() to minimise uaccess switches") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210608134605.2783677-1-mpe@ellerman.id.au
2021-06-06Merge tag 'powerpc-5.13-5' of ↵Linus Torvalds8-57/+49
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Fix our KVM reverse map real-mode handling since we enabled huge vmalloc (in some configurations). Revert a recent change to our IOMMU code which broke some devices. Fix KVM handling of FSCR on P7/P8, which could have possibly let a guest crash it's Qemu. Fix kprobes validation of prefixed instructions across page boundary. Thanks to Alexey Kardashevskiy, Christophe Leroy, Fabiano Rosas, Frederic Barrat, Naveen N. Rao, and Nicholas Piggin" * tag 'powerpc-5.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: Revert "powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs" KVM: PPC: Book3S HV: Save host FSCR in the P7/8 path powerpc: Fix reverse map real-mode address lookup with huge vmalloc powerpc/kprobes: Fix validation of prefixed instructions across page boundary
2021-06-06powerpc/mem: Add back missing header to fix 'no previous prototype' errorChristophe Leroy1-0/+1
Commit b26e8f27253a ("powerpc/mem: Move cache flushing functions into mm/cacheflush.c") removed asm/sparsemem.h which is required when CONFIG_MEMORY_HOTPLUG is selected to get the declaration of create_section_mapping(). Add it back. Fixes: b26e8f27253a ("powerpc/mem: Move cache flushing functions into mm/cacheflush.c") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3e5b63bb3daab54a1eb9c20221c2e9528c4db9b3.1622883330.git.christophe.leroy@csgroup.eu
2021-06-01Revert "powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs"Frederic Barrat1-6/+5
This reverts commit 3c0468d4451eb6b4f6604370639f163f9637a479. That commit was breaking alignment guarantees for the DMA address when allocating coherent mappings, as described in Documentation/core-api/dma-api-howto.rst It was also noticed by Mellanox' driver: [ 1515.763621] mlx5_core c002:01:00.0: mlx5_frag_buf_alloc_node:146:(pid 13402): unexpected map alignment: 0x0800000000c61000, page_shift=16 [ 1515.763635] mlx5_core c002:01:00.0: mlx5_cqwq_create:181:(pid 13402): mlx5_frag_buf_alloc_node() failed, -12 Fixes: 3c0468d4451e ("powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs") Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210526144540.117795-1-fbarrat@linux.ibm.com
2021-05-30Merge branch 'i2c/for-current' of ↵Linus Torvalds2-0/+24
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c fixes from Wolfram Sang: "This is a bit larger than usual at rc4 time. The reason is due to Lee's work of fixing newly reported build warnings. The rest is fixes as usual" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (22 commits) MAINTAINERS: adjust to removing i2c designware platform data i2c: s3c2410: fix possible NULL pointer deref on read message after write i2c: mediatek: Disable i2c start_en and clear intr_stat brfore reset i2c: i801: Don't generate an interrupt on bus reset i2c: mpc: implement erratum A-004447 workaround powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P1010 i2c controllers powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P2041 i2c controllers dt-bindings: i2c: mpc: Add fsl,i2c-erratum-a004447 flag i2c: busses: i2c-stm32f4: Remove incorrectly placed ' ' from function name i2c: busses: i2c-st: Fix copy/paste function misnaming issues i2c: busses: i2c-pnx: Provide descriptions for 'alg_data' data structure i2c: busses: i2c-ocores: Place the expected function names into the documentation headers i2c: busses: i2c-eg20t: Fix 'bad line' issue and provide description for 'msgs' param i2c: busses: i2c-designware-master: Fix misnaming of 'i2c_dw_init_master()' i2c: busses: i2c-cadence: Fix incorrectly documented 'enum cdns_i2c_slave_mode' i2c: busses: i2c-ali1563: File headers are not good candidates for kernel-doc i2c: muxes: i2c-arb-gpio-challenge: Demote non-conformant kernel-doc headers i2c: busses: i2c-nomadik: Fix formatting issue pertaining to 'timeout' i2c: sh_mobile: Use new clock calculation formulas for RZ/G2E i2c: I2C_HISI should depend on ACPI ...