Linux-kselftest-mirror February 2021

linux-kselftest-mirror@lists.linaro.org

75 participants
85 discussions

[PATCH v8 00/14] prohibit pinning pages in ZONE_MOVABLE

by Pavel Tatashin

Changelog --------- v8 - Added reviewed by's from John Hubbard - Fixed subjects for selftests patches - Moved zero page check inside is_pinnable_page() as requested by Jason Gunthorpe. v7 - Added reviewed-by's - Fixed a compile bug on non-mmu builds reported by robot v6 Small update, but I wanted to send it out quicker, as it removes a controversial patch and replaces it with something sane. - Removed forcing FOLL_WRITE for longterm gup, instead added a patch to skip zero pages during migration. - Added reviewed-by's and minor log changes. v5 - Added the following patches to the beginning of series, which are fixes to the other existing problems with CMA migration code: mm/gup: check every subpage of a compound page during isolation mm/gup: return an error on migration failure mm/gup: check for isolation errors also at the beginning of series mm/gup: do not allow zero page for pinned pages - remove .gfp_mask/.reclaim_idx changes from mm/vmscan.c - update movable zone header comment in patch 8 instead of patch 3, fix the comment - Added acked, sign-offs - Updated commit logs based on feedback - Addressed issues reported by Michal and Jason. - Remove: #define PINNABLE_MIGRATE_MAX 10 #define PINNABLE_ISOLATE_MAX 100 Instead: fail on the first migration failure, and retry isolation forever as their failures are transient. - In self-set addressed some of the comments from John Hubbard, updated commit logs, and added comments. Renamed gup->flags with gup->test_flags. v4 - Address page migration comments. New patch: mm/gup: limit number of gup migration failures, honor failures Implements the limiting number of retries for migration failures, and also check for isolation failures. Added a test case into gup_test to verify that pages never long-term pinned in a movable zone, and also added tests to fault both in kernel and in userland. v3 - Merged with linux-next, which contains clean-up patch from Jason, therefore this series is reduced by two patches which did the same thing. v2 - Addressed all review comments - Added Reviewed-by's. - Renamed PF_MEMALLOC_NOMOVABLE to PF_MEMALLOC_PIN - Added is_pinnable_page() to check if page can be longterm pinned - Fixed gup fast path by checking is_in_pinnable_zone() - rename cma_page_list to movable_page_list - add a admin-guide note about handling pinned pages in ZONE_MOVABLE, updated caveat about pinned pages from linux/mmzone.h - Move current_gfp_context() to fast-path --------- When page is pinned it cannot be moved and its physical address stays the same until pages is unpinned. This is useful functionality to allows userland to implementation DMA access. For example, it is used by vfio in vfio_pin_pages(). However, this functionality breaks memory hotplug/hotremove assumptions that pages in ZONE_MOVABLE can always be migrated. This patch series fixes this issue by forcing new allocations during page pinning to omit ZONE_MOVABLE, and also to migrate any existing pages from ZONE_MOVABLE during pinning. It uses the same scheme logic that is currently used by CMA, and extends the functionality for all allocations. For more information read the discussion [1] about this problem. [1] https://lore.kernel.org/lkml/CA+CK2bBffHBxjmb9jmSKacm0fJMinyt3Nhk8Nx6iudcQS… Previous versions: v1 https://lore.kernel.org/lkml/20201202052330.474592-1-pasha.tatashin@soleen.… v2 https://lore.kernel.org/lkml/20201210004335.64634-1-pasha.tatashin@soleen.c… v3 https://lore.kernel.org/lkml/20201211202140.396852-1-pasha.tatashin@soleen.… v4 https://lore.kernel.org/lkml/20201217185243.3288048-1-pasha.tatashin@soleen… v5 https://lore.kernel.org/lkml/20210119043920.155044-1-pasha.tatashin@soleen.… v6 https://lore.kernel.org/lkml/20210120014333.222547-1-pasha.tatashin@soleen.… v7 https://lore.kernel.org/lkml/20210122033748.924330-1-pasha.tatashin@soleen.… Pavel Tatashin (14): mm/gup: don't pin migrated cma pages in movable zone mm/gup: check every subpage of a compound page during isolation mm/gup: return an error on migration failure mm/gup: check for isolation errors mm cma: rename PF_MEMALLOC_NOCMA to PF_MEMALLOC_PIN mm: apply per-task gfp constraints in fast path mm: honor PF_MEMALLOC_PIN for all movable pages mm/gup: do not migrate zero page mm/gup: migrate pinned pages out of movable zone memory-hotplug.rst: add a note about ZONE_MOVABLE and page pinning mm/gup: change index type to long as it counts pages mm/gup: longterm pin migration cleanup selftests/vm: gup_test: fix test flag selftests/vm: gup_test: test faulting in kernel, and verify pinnable pages .../admin-guide/mm/memory-hotplug.rst | 9 + include/linux/migrate.h | 1 + include/linux/mm.h | 12 ++ include/linux/mmzone.h | 13 +- include/linux/pgtable.h | 3 +- include/linux/sched.h | 2 +- include/linux/sched/mm.h | 27 +-- include/trace/events/migrate.h | 3 +- mm/gup.c | 174 ++++++++---------- mm/gup_test.c | 29 +-- mm/gup_test.h | 3 +- mm/hugetlb.c | 4 +- mm/page_alloc.c | 33 ++-- tools/testing/selftests/vm/gup_test.c | 36 +++- 14 files changed, 190 insertions(+), 159 deletions(-) -- 2.25.1

3 years, 2 months

[PATCH v5 5/5] selftest/x86/signal: Include test cases for validating sigaltstack

by Chang S. Bae

The test measures the kernel's signal delivery with different (enough vs. insufficient) stack sizes. Signed-off-by: Chang S. Bae <chang.seok.bae(a)intel.com> Reviewed-by: Len Brown <len.brown(a)intel.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: x86(a)kernel.org Cc: linux-kselftest(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org --- Changes from v3: * Revised test messages again (Borislav Petkov) Changes from v2: * Revised test messages (Borislav Petkov) --- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/sigaltstack.c | 128 ++++++++++++++++++++++ 2 files changed, 129 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/sigaltstack.c diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 333980375bc7..65bba2ae86ee 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -13,7 +13,7 @@ CAN_BUILD_WITH_NOPIE := $(shell ./check_cc.sh $(CC) trivial_program.c -no-pie) TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \ check_initial_reg_state sigreturn iopl ioperm \ test_vsyscall mov_ss_trap \ - syscall_arg_fault fsgsbase_restore + syscall_arg_fault fsgsbase_restore sigaltstack TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer diff --git a/tools/testing/selftests/x86/sigaltstack.c b/tools/testing/selftests/x86/sigaltstack.c new file mode 100644 index 000000000000..f689af75e979 --- /dev/null +++ b/tools/testing/selftests/x86/sigaltstack.c @@ -0,0 +1,128 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#define _GNU_SOURCE +#include <signal.h> +#include <stdio.h> +#include <stdbool.h> +#include <string.h> +#include <err.h> +#include <errno.h> +#include <limits.h> +#include <sys/mman.h> +#include <sys/auxv.h> +#include <sys/prctl.h> +#include <sys/resource.h> +#include <setjmp.h> + +/* sigaltstack()-enforced minimum stack */ +#define ENFORCED_MINSIGSTKSZ 2048 + +#ifndef AT_MINSIGSTKSZ +# define AT_MINSIGSTKSZ 51 +#endif + +static int nerrs; + +static bool sigalrm_expected; + +static unsigned long at_minstack_size; + +static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), + int flags) +{ + struct sigaction sa; + + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO | flags; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static void clearhandler(int sig) +{ + struct sigaction sa; + + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static int setup_altstack(void *start, unsigned long size) +{ + stack_t ss; + + memset(&ss, 0, sizeof(ss)); + ss.ss_size = size; + ss.ss_sp = start; + + return sigaltstack(&ss, NULL); +} + +static jmp_buf jmpbuf; + +static void sigsegv(int sig, siginfo_t *info, void *ctx_void) +{ + if (sigalrm_expected) { + printf("[FAIL]\tWrong signal delivered: SIGSEGV (expected SIGALRM)."); + nerrs++; + } else { + printf("[OK]\tSIGSEGV signal delivered.\n"); + } + + siglongjmp(jmpbuf, 1); +} + +static void sigalrm(int sig, siginfo_t *info, void *ctx_void) +{ + if (!sigalrm_expected) { + printf("[FAIL]\tWrong signal delivered: SIGALRM (expected SIGSEGV)."); + nerrs++; + } else { + printf("[OK]\tSIGALRM signal delivered.\n"); + } +} + +static void test_sigaltstack(void *altstack, unsigned long size) +{ + if (setup_altstack(altstack, size)) + err(1, "sigaltstack()"); + + sigalrm_expected = (size > at_minstack_size) ? true : false; + + sethandler(SIGSEGV, sigsegv, 0); + sethandler(SIGALRM, sigalrm, SA_ONSTACK); + + if (!sigsetjmp(jmpbuf, 1)) { + printf("[RUN]\tTest an alternate signal stack of %ssufficient size.\n", + sigalrm_expected ? "" : "in"); + printf("\tRaise SIGALRM. %s is expected to be delivered.\n", + sigalrm_expected ? "It" : "SIGSEGV"); + raise(SIGALRM); + } + + clearhandler(SIGALRM); + clearhandler(SIGSEGV); +} + +int main(void) +{ + void *altstack; + + at_minstack_size = getauxval(AT_MINSIGSTKSZ); + + altstack = mmap(NULL, at_minstack_size + SIGSTKSZ, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); + if (altstack == MAP_FAILED) + err(1, "mmap()"); + + if ((ENFORCED_MINSIGSTKSZ + 1) < at_minstack_size) + test_sigaltstack(altstack, ENFORCED_MINSIGSTKSZ + 1); + + test_sigaltstack(altstack, at_minstack_size + SIGSTKSZ); + + return nerrs == 0 ? 0 : 1; +} -- 2.17.1

3 years, 2 months

[PATCH] selftests/powerpc: make the test check in eeh-basic.sh posix compliant

by Po-Hsu Lin

The == operand is a bash extension, thus this will fail on Ubuntu with As the /bin/sh on Ubuntu is pointed to DASH. Use -eq to fix this posix compatibility issue. Fixes: 996f9e0f93f162 ("selftests/powerpc: Fix eeh-basic.sh exit codes") Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com> --- tools/testing/selftests/powerpc/eeh/eeh-basic.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/powerpc/eeh/eeh-basic.sh b/tools/testing/selftests/powerpc/eeh/eeh-basic.sh index 0d783e1..64779f0 100755 --- a/tools/testing/selftests/powerpc/eeh/eeh-basic.sh +++ b/tools/testing/selftests/powerpc/eeh/eeh-basic.sh @@ -86,5 +86,5 @@ echo "$failed devices failed to recover ($dev_count tested)" lspci | diff -u $pre_lspci - rm -f $pre_lspci -test "$failed" == 0 +test "$failed" -eq 0 exit $? -- 2.7.4

3 years, 2 months

[PATCH v9 00/14] prohibit pinning pages in ZONE_MOVABLE

by Pavel Tatashin

Changelog --------- v9 - Renamed gpf_to_alloc_flags() to gfp_to_alloc_flags_cma(); thanks Lecopzer Chen for noticing. - Fixed warning reported scripts/checkpatch.pl: "Logical continuations should be on the previous line" v8 - Added reviewed by's from John Hubbard - Fixed subjects for selftests patches - Moved zero page check inside is_pinnable_page() as requested by Jason Gunthorpe. v7 - Added reviewed-by's - Fixed a compile bug on non-mmu builds reported by robot v6 Small update, but I wanted to send it out quicker, as it removes a controversial patch and replaces it with something sane. - Removed forcing FOLL_WRITE for longterm gup, instead added a patch to skip zero pages during migration. - Added reviewed-by's and minor log changes. v5 - Added the following patches to the beginning of series, which are fixes to the other existing problems with CMA migration code: mm/gup: check every subpage of a compound page during isolation mm/gup: return an error on migration failure mm/gup: check for isolation errors also at the beginning of series mm/gup: do not allow zero page for pinned pages - remove .gfp_mask/.reclaim_idx changes from mm/vmscan.c - update movable zone header comment in patch 8 instead of patch 3, fix the comment - Added acked, sign-offs - Updated commit logs based on feedback - Addressed issues reported by Michal and Jason. - Remove: #define PINNABLE_MIGRATE_MAX 10 #define PINNABLE_ISOLATE_MAX 100 Instead: fail on the first migration failure, and retry isolation forever as their failures are transient. - In self-set addressed some of the comments from John Hubbard, updated commit logs, and added comments. Renamed gup->flags with gup->test_flags. v4 - Address page migration comments. New patch: mm/gup: limit number of gup migration failures, honor failures Implements the limiting number of retries for migration failures, and also check for isolation failures. Added a test case into gup_test to verify that pages never long-term pinned in a movable zone, and also added tests to fault both in kernel and in userland. v3 - Merged with linux-next, which contains clean-up patch from Jason, therefore this series is reduced by two patches which did the same thing. v2 - Addressed all review comments - Added Reviewed-by's. - Renamed PF_MEMALLOC_NOMOVABLE to PF_MEMALLOC_PIN - Added is_pinnable_page() to check if page can be longterm pinned - Fixed gup fast path by checking is_in_pinnable_zone() - rename cma_page_list to movable_page_list - add a admin-guide note about handling pinned pages in ZONE_MOVABLE, updated caveat about pinned pages from linux/mmzone.h - Move current_gfp_context() to fast-path --------- When page is pinned it cannot be moved and its physical address stays the same until pages is unpinned. This is useful functionality to allows userland to implementation DMA access. For example, it is used by vfio in vfio_pin_pages(). However, this functionality breaks memory hotplug/hotremove assumptions that pages in ZONE_MOVABLE can always be migrated. This patch series fixes this issue by forcing new allocations during page pinning to omit ZONE_MOVABLE, and also to migrate any existing pages from ZONE_MOVABLE during pinning. It uses the same scheme logic that is currently used by CMA, and extends the functionality for all allocations. For more information read the discussion [1] about this problem. [1] https://lore.kernel.org/lkml/CA+CK2bBffHBxjmb9jmSKacm0fJMinyt3Nhk8Nx6iudcQS… Previous versions: v1 https://lore.kernel.org/lkml/20201202052330.474592-1-pasha.tatashin@soleen.… v2 https://lore.kernel.org/lkml/20201210004335.64634-1-pasha.tatashin@soleen.c… v3 https://lore.kernel.org/lkml/20201211202140.396852-1-pasha.tatashin@soleen.… v4 https://lore.kernel.org/lkml/20201217185243.3288048-1-pasha.tatashin@soleen… v5 https://lore.kernel.org/lkml/20210119043920.155044-1-pasha.tatashin@soleen.… v6 https://lore.kernel.org/lkml/20210120014333.222547-1-pasha.tatashin@soleen.… v7 https://lore.kernel.org/lkml/20210122033748.924330-1-pasha.tatashin@soleen.… v8 https://lore.kernel.org/lkml/20210125194751.1275316-1-pasha.tatashin@soleen… Pavel Tatashin (14): mm/gup: don't pin migrated cma pages in movable zone mm/gup: check every subpage of a compound page during isolation mm/gup: return an error on migration failure mm/gup: check for isolation errors mm cma: rename PF_MEMALLOC_NOCMA to PF_MEMALLOC_PIN mm: apply per-task gfp constraints in fast path mm: honor PF_MEMALLOC_PIN for all movable pages mm/gup: do not migrate zero page mm/gup: migrate pinned pages out of movable zone memory-hotplug.rst: add a note about ZONE_MOVABLE and page pinning mm/gup: change index type to long as it counts pages mm/gup: longterm pin migration cleanup selftests/vm: gup_test: fix test flag selftests/vm: gup_test: test faulting in kernel, and verify pinnable pages .../admin-guide/mm/memory-hotplug.rst | 9 + include/linux/migrate.h | 1 + include/linux/mm.h | 12 ++ include/linux/mmzone.h | 13 +- include/linux/pgtable.h | 3 +- include/linux/sched.h | 2 +- include/linux/sched/mm.h | 27 +-- include/trace/events/migrate.h | 3 +- mm/gup.c | 174 ++++++++---------- mm/gup_test.c | 29 +-- mm/gup_test.h | 3 +- mm/hugetlb.c | 4 +- mm/page_alloc.c | 33 ++-- tools/testing/selftests/vm/gup_test.c | 36 +++- 14 files changed, 190 insertions(+), 159 deletions(-) -- 2.25.1

3 years, 2 months

Re: [PATCH v3 1/5] selftests/x86: Simplify the code to get vdso base address in sgx

by Jarkko Sakkinen

What the short summary is saying now, is that this commit would make the existing code to use vDSO base address. It's already doing that. You could instead just "Use getauxval() to simplify the code". Also, I'd prefer to properly use upper and lower case letter, e.g. vDSO instead of vdso. Reply-To: In-Reply-To: <20210124062907.88229-2-tianjia.zhang(a)linux.alibaba.com> On Sun, Jan 24, 2021 at 02:29:03PM +0800, Tianjia Zhang wrote: > This patch uses the library function `getauxval(AT_SYSINFO_EHDR)` > instead of the custom function `vdso_get_base_addr` to obtain the Use either double or single quotation mark instead of hyphen. > base address of vDSO, which will simplify the code implementation. > > Signed-off-by: Tianjia Zhang <tianjia.zhang(a)linux.alibaba.com> This needs to be imperative form, e.g. "Simplify the code implemntation by using getauxval() instead of a custom function." > --- > tools/testing/selftests/sgx/main.c | 24 ++++-------------------- > 1 file changed, 4 insertions(+), 20 deletions(-) > > diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c > index 724cec700926..365d01dea67b 100644 > --- a/tools/testing/selftests/sgx/main.c > +++ b/tools/testing/selftests/sgx/main.c > @@ -15,6 +15,7 @@ > #include <sys/stat.h> > #include <sys/time.h> > #include <sys/types.h> > +#include <sys/auxv.h> > #include "defines.h" > #include "main.h" > #include "../kselftest.h" > @@ -28,24 +29,6 @@ struct vdso_symtab { > Elf64_Word *elf_hashtab; > }; > > -static void *vdso_get_base_addr(char *envp[]) > -{ > - Elf64_auxv_t *auxv; > - int i; > - > - for (i = 0; envp[i]; i++) > - ; > - > - auxv = (Elf64_auxv_t *)&envp[i + 1]; > - > - for (i = 0; auxv[i].a_type != AT_NULL; i++) { > - if (auxv[i].a_type == AT_SYSINFO_EHDR) > - return (void *)auxv[i].a_un.a_val; > - } > - > - return NULL; > -} > - > static Elf64_Dyn *vdso_get_dyntab(void *addr) > { > Elf64_Ehdr *ehdr = addr; > @@ -162,7 +145,7 @@ static int user_handler(long rdi, long rsi, long rdx, long ursp, long r8, long r > return 0; > } > > -int main(int argc, char *argv[], char *envp[]) > +int main(int argc, char *argv[]) > { > struct sgx_enclave_run run; > struct vdso_symtab symtab; > @@ -203,7 +186,8 @@ int main(int argc, char *argv[], char *envp[]) > memset(&run, 0, sizeof(run)); > run.tcs = encl.encl_base; > > - addr = vdso_get_base_addr(envp); > + /* Get vDSO base address */ > + addr = (void *)(uintptr_t)getauxval(AT_SYSINFO_EHDR); You could just case the result the result directly to void *. > if (!addr) > goto err; > > -- > 2.19.1.3.ge56e4f7 > > /Jarkko

3 years, 2 months

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Linux-kselftest-mirror February 2021