From 92a5e1fdb286851d5bd0eb966b8d075be27cf5ee Mon Sep 17 00:00:00 2001 From: Sandipan Das Date: Mon, 18 Jan 2021 15:01:45 +0530 Subject: [PATCH 1/3] selftests/powerpc: Fix exit status of pkey tests Since main() does not return a value explicitly, the return values from FAIL_IF() conditions are ignored and the tests can still pass irrespective of failures. This makes sure that we always explicitly return the correct test exit status. Fixes: 1addb6444791 ("selftests/powerpc: Add test for execute-disabled pkeys") Fixes: c27f2fd1705a ("selftests/powerpc: Add test for pkey siginfo verification") Reported-by: Eirik Fuller Signed-off-by: Sandipan Das Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210118093145.10134-1-sandipan@linux.ibm.com --- tools/testing/selftests/powerpc/mm/pkey_exec_prot.c | 2 +- tools/testing/selftests/powerpc/mm/pkey_siginfo.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c index 9e5c7f3f498a7..0af4f02669a11 100644 --- a/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c +++ b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c @@ -290,5 +290,5 @@ static int test(void) int main(void) { - test_harness(test, "pkey_exec_prot"); + return test_harness(test, "pkey_exec_prot"); } diff --git a/tools/testing/selftests/powerpc/mm/pkey_siginfo.c b/tools/testing/selftests/powerpc/mm/pkey_siginfo.c index 4f815d7c12145..2db76e56d4cb9 100644 --- a/tools/testing/selftests/powerpc/mm/pkey_siginfo.c +++ b/tools/testing/selftests/powerpc/mm/pkey_siginfo.c @@ -329,5 +329,5 @@ static int test(void) int main(void) { - test_harness(test, "pkey_siginfo"); + return test_harness(test, "pkey_siginfo"); } From dd3a44c06f7b4f14e90065bf05d62c255b20005f Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 19 Jan 2021 15:18:00 +1100 Subject: [PATCH 2/3] selftests/powerpc: Only test lwm/stmw on big endian Newer binutils (>= 2.36) refuse to assemble lmw/stmw when building in little endian mode. That breaks compilation of our alignment handler test: /tmp/cco4l14N.s: Assembler messages: /tmp/cco4l14N.s:1440: Error: `lmw' invalid when little-endian /tmp/cco4l14N.s:1814: Error: `stmw' invalid when little-endian make[2]: *** [../../lib.mk:139: /output/kselftest/powerpc/alignment/alignment_handler] Error 1 These tests do pass on little endian machines, as the kernel will still emulate those instructions even when running little endian (which is arguably a kernel bug). But we don't really need to test that case, so ifdef those instructions out to get the alignment test building again. Reported-by: Libor Pechacek Signed-off-by: Michael Ellerman Tested-by: Libor Pechacek Link: https://lore.kernel.org/r/20210119041800.3093047-1-mpe@ellerman.id.au --- .../testing/selftests/powerpc/alignment/alignment_handler.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/powerpc/alignment/alignment_handler.c b/tools/testing/selftests/powerpc/alignment/alignment_handler.c index cb53a8b777e68..c25cf7cd45e9f 100644 --- a/tools/testing/selftests/powerpc/alignment/alignment_handler.c +++ b/tools/testing/selftests/powerpc/alignment/alignment_handler.c @@ -443,7 +443,6 @@ int test_alignment_handler_integer(void) LOAD_DFORM_TEST(ldu); LOAD_XFORM_TEST(ldx); LOAD_XFORM_TEST(ldux); - LOAD_DFORM_TEST(lmw); STORE_DFORM_TEST(stb); STORE_XFORM_TEST(stbx); STORE_DFORM_TEST(stbu); @@ -462,7 +461,11 @@ int test_alignment_handler_integer(void) STORE_XFORM_TEST(stdx); STORE_DFORM_TEST(stdu); STORE_XFORM_TEST(stdux); + +#ifdef __BIG_ENDIAN__ + LOAD_DFORM_TEST(lmw); STORE_DFORM_TEST(stmw); +#endif return rc; } From 08685be7761d69914f08c3d6211c543a385a5b9c Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Mon, 11 Jan 2021 16:24:08 +1000 Subject: [PATCH 3/3] powerpc/64s: fix scv entry fallback flush vs interrupt The L1D flush fallback functions are not recoverable vs interrupts, yet the scv entry flush runs with MSR[EE]=1. This can result in a timer (soft-NMI) or MCE or SRESET interrupt hitting here and overwriting the EXRFI save area, which ends up corrupting userspace registers for scv return. Fix this by disabling RI and EE for the scv entry fallback flush. Fixes: f79643787e0a0 ("powerpc/64s: flush L1D on kernel entry") Cc: stable@vger.kernel.org # 5.9+ which also have flush L1D patch backport Reported-by: Tulio Magno Quites Machado Filho Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210111062408.287092-1-npiggin@gmail.com --- arch/powerpc/include/asm/exception-64s.h | 13 ++++++++++++ arch/powerpc/include/asm/feature-fixups.h | 10 ++++++++++ arch/powerpc/kernel/entry_64.S | 2 +- arch/powerpc/kernel/exceptions-64s.S | 19 ++++++++++++++++++ arch/powerpc/kernel/vmlinux.lds.S | 7 +++++++ arch/powerpc/lib/feature-fixups.c | 24 ++++++++++++++++++++--- 6 files changed, 71 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index 1d32b174ab6ae..c1a8aac01cf91 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -63,6 +63,12 @@ nop; \ nop; +#define SCV_ENTRY_FLUSH_SLOT \ + SCV_ENTRY_FLUSH_FIXUP_SECTION; \ + nop; \ + nop; \ + nop; + /* * r10 must be free to use, r13 must be paca */ @@ -70,6 +76,13 @@ STF_ENTRY_BARRIER_SLOT; \ ENTRY_FLUSH_SLOT +/* + * r10, ctr must be free to use, r13 must be paca + */ +#define SCV_INTERRUPT_TO_KERNEL \ + STF_ENTRY_BARRIER_SLOT; \ + SCV_ENTRY_FLUSH_SLOT + /* * Macros for annotating the expected destination of (h)rfid * diff --git a/arch/powerpc/include/asm/feature-fixups.h b/arch/powerpc/include/asm/feature-fixups.h index f6d2acb574252..ac605fc369c42 100644 --- a/arch/powerpc/include/asm/feature-fixups.h +++ b/arch/powerpc/include/asm/feature-fixups.h @@ -240,6 +240,14 @@ label##3: \ FTR_ENTRY_OFFSET 957b-958b; \ .popsection; +#define SCV_ENTRY_FLUSH_FIXUP_SECTION \ +957: \ + .pushsection __scv_entry_flush_fixup,"a"; \ + .align 2; \ +958: \ + FTR_ENTRY_OFFSET 957b-958b; \ + .popsection; + #define RFI_FLUSH_FIXUP_SECTION \ 951: \ .pushsection __rfi_flush_fixup,"a"; \ @@ -273,10 +281,12 @@ label##3: \ extern long stf_barrier_fallback; extern long entry_flush_fallback; +extern long scv_entry_flush_fallback; extern long __start___stf_entry_barrier_fixup, __stop___stf_entry_barrier_fixup; extern long __start___stf_exit_barrier_fixup, __stop___stf_exit_barrier_fixup; extern long __start___uaccess_flush_fixup, __stop___uaccess_flush_fixup; extern long __start___entry_flush_fixup, __stop___entry_flush_fixup; +extern long __start___scv_entry_flush_fixup, __stop___scv_entry_flush_fixup; extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup; extern long __start___barrier_nospec_fixup, __stop___barrier_nospec_fixup; extern long __start__btb_flush_fixup, __stop__btb_flush_fixup; diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index aa1af139d9472..33ddfeef4fe9e 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -75,7 +75,7 @@ BEGIN_FTR_SECTION bne .Ltabort_syscall END_FTR_SECTION_IFSET(CPU_FTR_TM) #endif - INTERRUPT_TO_KERNEL + SCV_INTERRUPT_TO_KERNEL mr r10,r1 ld r1,PACAKSAVE(r13) std r10,0(r1) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index e02ad6fefa46c..6e53f76387374 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -2993,6 +2993,25 @@ TRAMP_REAL_BEGIN(entry_flush_fallback) ld r11,PACA_EXRFI+EX_R11(r13) blr +/* + * The SCV entry flush happens with interrupts enabled, so it must disable + * to prevent EXRFI being clobbered by NMIs (e.g., soft_nmi_common). r10 + * (containing LR) does not need to be preserved here because scv entry + * puts 0 in the pt_regs, CTR can be clobbered for the same reason. + */ +TRAMP_REAL_BEGIN(scv_entry_flush_fallback) + li r10,0 + mtmsrd r10,1 + lbz r10,PACAIRQHAPPENED(r13) + ori r10,r10,PACA_IRQ_HARD_DIS + stb r10,PACAIRQHAPPENED(r13) + std r11,PACA_EXRFI+EX_R11(r13) + L1D_DISPLACEMENT_FLUSH + ld r11,PACA_EXRFI+EX_R11(r13) + li r10,MSR_RI + mtmsrd r10,1 + blr + TRAMP_REAL_BEGIN(rfi_flush_fallback) SET_SCRATCH0(r13); GET_PACA(r13); diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index 4ab426b8b0e02..72fa3c00229a5 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -145,6 +145,13 @@ SECTIONS __stop___entry_flush_fixup = .; } + . = ALIGN(8); + __scv_entry_flush_fixup : AT(ADDR(__scv_entry_flush_fixup) - LOAD_OFFSET) { + __start___scv_entry_flush_fixup = .; + *(__scv_entry_flush_fixup) + __stop___scv_entry_flush_fixup = .; + } + . = ALIGN(8); __stf_exit_barrier_fixup : AT(ADDR(__stf_exit_barrier_fixup) - LOAD_OFFSET) { __start___stf_exit_barrier_fixup = .; diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c index 47821055b94c9..1fd31b4b0e139 100644 --- a/arch/powerpc/lib/feature-fixups.c +++ b/arch/powerpc/lib/feature-fixups.c @@ -290,9 +290,6 @@ void do_entry_flush_fixups(enum l1d_flush_type types) long *start, *end; int i; - start = PTRRELOC(&__start___entry_flush_fixup); - end = PTRRELOC(&__stop___entry_flush_fixup); - instrs[0] = 0x60000000; /* nop */ instrs[1] = 0x60000000; /* nop */ instrs[2] = 0x60000000; /* nop */ @@ -312,6 +309,8 @@ void do_entry_flush_fixups(enum l1d_flush_type types) if (types & L1D_FLUSH_MTTRIG) instrs[i++] = 0x7c12dba6; /* mtspr TRIG2,r0 (SPR #882) */ + start = PTRRELOC(&__start___entry_flush_fixup); + end = PTRRELOC(&__stop___entry_flush_fixup); for (i = 0; start < end; start++, i++) { dest = (void *)start + *start; @@ -328,6 +327,25 @@ void do_entry_flush_fixups(enum l1d_flush_type types) patch_instruction((struct ppc_inst *)(dest + 2), ppc_inst(instrs[2])); } + start = PTRRELOC(&__start___scv_entry_flush_fixup); + end = PTRRELOC(&__stop___scv_entry_flush_fixup); + for (; start < end; start++, i++) { + dest = (void *)start + *start; + + pr_devel("patching dest %lx\n", (unsigned long)dest); + + patch_instruction((struct ppc_inst *)dest, ppc_inst(instrs[0])); + + if (types == L1D_FLUSH_FALLBACK) + patch_branch((struct ppc_inst *)(dest + 1), (unsigned long)&scv_entry_flush_fallback, + BRANCH_SET_LINK); + else + patch_instruction((struct ppc_inst *)(dest + 1), ppc_inst(instrs[1])); + + patch_instruction((struct ppc_inst *)(dest + 2), ppc_inst(instrs[2])); + } + + printk(KERN_DEBUG "entry-flush: patched %d locations (%s flush)\n", i, (types == L1D_FLUSH_NONE) ? "no" : (types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :