December 2020 - Linux-kselftest-mirror

[PATCH] kunit: tool: Force the use of the 'tty' console for UML

by David Gow

kunit_tool relies on the UML console outputting printk() output to the tty in order to get results. Since the default console driver could change, pass 'console=tty' to the kernel. This is triggered by a change[1] to use ttynull as a fallback console driver which -- by chance or by design -- seems to have changed the default console output on UML, breaking kunit_tool. While this may be fixed, we should be less fragile to such changes in the default. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… Signed-off-by: David Gow <davidgow(a)google.com> Fixes: 757055ae8ded ("init/console: Use ttynull as a fallback when there is no console") --- tools/testing/kunit/kunit_kernel.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py index 57c1724b7e5d..698358c9c0d6 100644 --- a/tools/testing/kunit/kunit_kernel.py +++ b/tools/testing/kunit/kunit_kernel.py @@ -198,7 +198,7 @@ class LinuxSourceTree(object): return self.validate_config(build_dir) def run_kernel(self, args=[], build_dir='', timeout=None): - args.extend(['mem=1G']) + args.extend(['mem=1G', 'console=tty']) self._ops.linux_bin(args, timeout, build_dir) outfile = get_outfile_path(build_dir) subprocess.call(['stty', 'sane']) -- 2.29.2.729.g45daf8777d-goog

3 years, 11 months

5
10
0 0

kunit stopped working

by Andy Shevchenko

Hi! For last few weeks KUnit stopped working. Any insight? P.S. I guess no need to tell that my kernel on which I run tests has not been changed as well as command line for wrapper: tools/testing/kunit/kunit.py run --build_dir ~/$OUT_DIR -- With Best Regards, Andy Shevchenko

3 years, 11 months

6
14
0 0

[PATCH] selftests: xfrm: fix test return value override issue in xfrm_policy.sh

by Po-Hsu Lin

When running this xfrm_policy.sh test script, even with some cases marked as FAIL, the overall test result will still be PASS: $ sudo ./xfrm_policy.sh PASS: policy before exception matches FAIL: expected ping to .254 to fail (exceptions) PASS: direct policy matches (exceptions) PASS: policy matches (exceptions) FAIL: expected ping to .254 to fail (exceptions and block policies) PASS: direct policy matches (exceptions and block policies) PASS: policy matches (exceptions and block policies) FAIL: expected ping to .254 to fail (exceptions and block policies after hresh changes) PASS: direct policy matches (exceptions and block policies after hresh changes) PASS: policy matches (exceptions and block policies after hresh changes) FAIL: expected ping to .254 to fail (exceptions and block policies after hthresh change in ns3) PASS: direct policy matches (exceptions and block policies after hthresh change in ns3) PASS: policy matches (exceptions and block policies after hthresh change in ns3) FAIL: expected ping to .254 to fail (exceptions and block policies after htresh change to normal) PASS: direct policy matches (exceptions and block policies after htresh change to normal) PASS: policy matches (exceptions and block policies after htresh change to normal) PASS: policies with repeated htresh change $ echo $? 0 This is because the $lret in check_xfrm() is not a local variable. Therefore when a test failed in check_exceptions(), the non-zero $lret will later get reset to 0 when the next test calls check_xfrm(). With this fix, the final return value will be 1. Make it easier for testers to spot this failure. Fixes: 39aa6928d462d0 ("xfrm: policy: fix netlink/pf_key policy lookups") Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com> --- tools/testing/selftests/net/xfrm_policy.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/net/xfrm_policy.sh b/tools/testing/selftests/net/xfrm_policy.sh index 7a1bf94..5922941 100755 --- a/tools/testing/selftests/net/xfrm_policy.sh +++ b/tools/testing/selftests/net/xfrm_policy.sh @@ -202,7 +202,7 @@ check_xfrm() { # 1: iptables -m policy rule count != 0 rval=$1 ip=$2 - lret=0 + local lret=0 ip netns exec ns1 ping -q -c 1 10.0.2.$ip > /dev/null -- 2.7.4

3 years, 11 months

3
2
0 0

[PATCH V3 00/10] PKS: Add Protection Keys Supervisor (PKS) support V3

by ira.weiny＠intel.com

From: Ira Weiny <ira.weiny(a)intel.com> Changes from V2 [4] Rebased on tip-tree/core/entry From Thomas Gleixner Address bisectability Drop Patch: x86/entry: Move nmi entry/exit into common code From Greg KH Remove WARN_ON's From Dan Williams Add __must_check to pks_key_alloc() New patch: x86/pks: Add PKS defines and config options Split from Enable patch to build on through the series Fix compile errors Changes from V1 Rebase to TIP master; resolve conflicts and test Clean up some kernel docs updates missed in V1 Add irqentry_state_t kernel doc for PKRS field Removed redundant irq_state->pkrs This is only needed when we add the global state and somehow ended up in this patch series. That will come back when we add the global functionality in. From Thomas Gleixner Update commit messages Add kernel doc for struct irqentry_state_t From Dave Hansen add flags to pks_key_alloc() Changes from RFC V3[3] Rebase to TIP master Update test error output Standardize on 'irq_state' for state variables From Dave Hansen Update commit messages Add/clean up comments Add X86_FEATURE_PKS to disabled-features.h and remove some explicit CONFIG checks Move saved_pkrs member of thread_struct Remove superfluous preempt_disable() s/irq_save_pks/irq_save_set_pks/ Ensure PKRS is not seen in faults if not configured or not supported s/pks_mknoaccess/pks_mk_noaccess/ s/pks_mkread/pks_mk_readonly/ s/pks_mkrdwr/pks_mk_readwrite/ Change pks_key_alloc return to -EOPNOTSUPP when not supported From Peter Zijlstra Clean up Attribution Remove superfluous preempt_disable() Add union to differentiate exit_rcu/lockdep use in irqentry_state_t From Thomas Gleixner Add preliminary clean up patch and adjust series as needed Introduce a new page protection mechanism for supervisor pages, Protection Key Supervisor (PKS). 2 use cases for PKS are being developed, trusted keys and PMEM. Trusted keys is a newer use case which is still being explored. PMEM was submitted as part of the RFC (v2) series[1]. However, since then it was found that some callers of kmap() require a global implementation of PKS. Specifically some users of kmap() expect mappings to be available to all kernel threads. While global use of PKS is rare it needs to be included for correctness. Unfortunately the kmap() updates required a large patch series to make the needed changes at the various kmap() call sites so that patch set has been split out. Because the global PKS feature is only required for that use case it will be deferred to that set as well.[2] This patch set is being submitted as a precursor to both of the use cases. For an overview of the entire PKS ecosystem, a git tree including this series and 2 proposed use cases can be found here: https://lore.kernel.org/lkml/20201009195033.3208459-1-ira.weiny@intel.com/ https://lore.kernel.org/lkml/20201009201410.3209180-1-ira.weiny@intel.com/ PKS enables protections on 'domains' of supervisor pages to limit supervisor mode access to those pages beyond the normal paging protections. PKS works in a similar fashion to user space pkeys, PKU. As with PKU, supervisor pkeys are checked in addition to normal paging protections and Access or Writes can be disabled via a MSR update without TLB flushes when permissions change. Also like PKU, a page mapping is assigned to a domain by setting pkey bits in the page table entry for that mapping. Access is controlled through a PKRS register which is updated via WRMSR/RDMSR. XSAVE is not supported for the PKRS MSR. Therefore the implementation saves/restores the MSR across context switches and during exceptions. Nested exceptions are supported by each exception getting a new PKS state. For consistent behavior with current paging protections, pkey 0 is reserved and configured to allow full access via the pkey mechanism, thus preserving the default paging protections on mappings with the default pkey value of 0. Other keys, (1-15) are allocated by an allocator which prepares us for key contention from day one. Kernel users should be prepared for the allocator to fail either because of key exhaustion or due to PKS not being supported on the arch and/or CPU instance. The following are key attributes of PKS. 1) Fast switching of permissions 1a) Prevents access without page table manipulations 1b) No TLB flushes required 2) Works on a per thread basis PKS is available with 4 and 5 level paging. Like PKRU it consumes 4 bits from the PTE to store the pkey within the entry. [1] https://lore.kernel.org/lkml/20200717072056.73134-1-ira.weiny@intel.com/ [2] https://lore.kernel.org/lkml/20201009195033.3208459-2-ira.weiny@intel.com/ [3] https://lore.kernel.org/lkml/20201009194258.3207172-1-ira.weiny@intel.com/ [4] https://lore.kernel.org/lkml/20201102205320.1458656-1-ira.weiny@intel.com/ Fenghua Yu (2): x86/pks: Add PKS kernel API x86/pks: Enable Protection Keys Supervisor (PKS) Ira Weiny (8): x86/pkeys: Create pkeys_common.h x86/fpu: Refactor arch_set_user_pkey_access() for PKS support x86/pks: Add PKS defines and Kconfig options x86/pks: Preserve the PKRS MSR on context switch x86/entry: Pass irqentry_state_t by reference x86/entry: Preserve PKRS MSR across exceptions x86/fault: Report the PKRS state on fault x86/pks: Add PKS test code Documentation/core-api/protection-keys.rst | 103 ++- arch/x86/Kconfig | 1 + arch/x86/entry/common.c | 46 +- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/disabled-features.h | 8 +- arch/x86/include/asm/idtentry.h | 25 +- arch/x86/include/asm/msr-index.h | 1 + arch/x86/include/asm/pgtable.h | 13 +- arch/x86/include/asm/pgtable_types.h | 12 + arch/x86/include/asm/pkeys.h | 15 + arch/x86/include/asm/pkeys_common.h | 40 ++ arch/x86/include/asm/processor.h | 18 +- arch/x86/include/uapi/asm/processor-flags.h | 2 + arch/x86/kernel/cpu/common.c | 15 + arch/x86/kernel/cpu/mce/core.c | 4 +- arch/x86/kernel/fpu/xstate.c | 22 +- arch/x86/kernel/kvm.c | 6 +- arch/x86/kernel/nmi.c | 4 +- arch/x86/kernel/process.c | 26 + arch/x86/kernel/traps.c | 21 +- arch/x86/mm/fault.c | 87 ++- arch/x86/mm/pkeys.c | 196 +++++- include/linux/entry-common.h | 31 +- include/linux/pgtable.h | 4 + include/linux/pkeys.h | 24 + kernel/entry/common.c | 44 +- lib/Kconfig.debug | 12 + lib/Makefile | 3 + lib/pks/Makefile | 3 + lib/pks/pks_test.c | 692 ++++++++++++++++++++ mm/Kconfig | 2 + tools/testing/selftests/x86/Makefile | 3 +- tools/testing/selftests/x86/test_pks.c | 66 ++ 33 files changed, 1410 insertions(+), 140 deletions(-) create mode 100644 arch/x86/include/asm/pkeys_common.h create mode 100644 lib/pks/Makefile create mode 100644 lib/pks/pks_test.c create mode 100644 tools/testing/selftests/x86/test_pks.c -- 2.28.0.rc0.12.gb6a658bd00c9

3 years, 12 months

9
44
0 0

[PATCH v1 0/5] dm: dm-user: New target that proxies BIOs to userspace

by Palmer Dabbelt

This patch set contains dm-user, a device mapper target that proxies incoming BIOs to userspace via a misc device. Essentially it's FUSE, but for block devices. There's more information in the documentation patch and as a handful of commends, so I'm just going to avoid duplicating that here. I don't really think there's any fundamental functionality that dm-user enables, as one could use something along the lines of nbd/iscsi, but dm-user does result in extremely simple userspace daemons -- so simple that when I tried to write a helper userspace library for dm-user I just ended up with nothing. I talked about this a bit at Plumbers and was hoping to send patches a bit earlier on in the process, but got tied up with a few things. As a result this is actually quite far along: it's at the point where we're starting to run this on real devices as part of an updated Android OTA update flow, where we're using this to provide an Android-specific compressed backing store for dm-snap-persistent. The bulk of that project is scattered throughout the various Android trees, so there are kselftests and a (somewhat bare for now) Documentation entry with the intent of making this a self-contained contribution. There's a lot to the Android userspace daemon, but it doesn't interact with dm-user in a very complex manner. This is still in a somewhat early stage, but it's at the point where things largely function. I'm certainly not ready to commit to the user ABI implemented here and there are a bunch of FIXMEs scattered throughout the code, but I do think that it's far along enough to begin a more concrete discussion of where folks would like to go with something like this. While I'd intending on sorting that stuff out, I'd like to at least get a feel for whether this is a path worth pursuing before spending a bunch more time on it. I haven't done much in the way of performance analysis for dm-user. Earlier on I did some simple throughput tests and found that dm-user/ext4 was faster than half the speed of tmpfs, which is way out of the realm of being an issue for our use case (decompressing blocks out of a phone's storage). The design of dm-user does preclude an extremely high performance implementation, where I assume one would want an explicit ring buffer and zero copy, but I feel like users who want that degree of performance are probably better served writing a proper kernel driver. I wouldn't be opposed to pushing on performance (ideally without a major design change), but for now I feel like time is better spent fortifying the user ABI and fixing the various issues with the implementation. The patches follow as usual, but in case it's easier I've published a tree as well: git://git.kernel.org/pub/scm/linux/kernel/git/palmer/dm-user.git -b dm-user-v1

3 years, 12 months

6
18
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[PATCH v3 20/21] x86/fpu/xstate: Support dynamic user state in the signal handling path

by Chang S. Bae

Entering a signal handler, the kernel saves the XSAVE buffer. The dynamic user state is better to be saved only when used. fpu->state_mask can help to exclude unused states. Returning from a signal handler, XRSTOR re-initializes the excluded state components. Add a test case to verify in the signal handler that the signal frame excludes AMX data when the signaled thread has initialized AMX state. No functional change until the kernel supports the dynamic user states. Signed-off-by: Chang S. Bae <chang.seok.bae(a)intel.com> Reviewed-by: Len Brown <len.brown(a)intel.com> Cc: x86(a)kernel.org Cc: linux-kernel(a)vger.kernel.org Cc: linux-kselftest(a)vger.kernel.org --- Changes from v1: * Made it revertible (moved close to the end of the series). * Included the test case. --- arch/x86/include/asm/fpu/internal.h | 2 +- tools/testing/selftests/x86/amx.c | 66 +++++++++++++++++++++++++++++ 2 files changed, 67 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 5eba9a466249..202874bb79da 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -369,7 +369,7 @@ static inline void copy_kernel_to_xregs(struct xregs_state *xstate, u64 mask) */ static inline int copy_xregs_to_user(struct xregs_state __user *buf) { - u64 mask = xfeatures_mask_user(); + u64 mask = current->thread.fpu.state_mask; u32 lmask = mask; u32 hmask = mask >> 32; int err; diff --git a/tools/testing/selftests/x86/amx.c b/tools/testing/selftests/x86/amx.c index f4ecdfd27ae9..a7386b886532 100644 --- a/tools/testing/selftests/x86/amx.c +++ b/tools/testing/selftests/x86/amx.c @@ -650,6 +650,71 @@ static void test_ptrace(void) test_tile_state_write(ptracee_loads_tiles); } +/* Signal handling test */ + +static int sigtrapped; +struct tile_data sig_tiles, sighdl_tiles; + +static void handle_sigtrap(int sig, siginfo_t *info, void *ctx_void) +{ + ucontext_t *uctxt = (ucontext_t *)ctx_void; + struct xsave_data xdata; + struct tile_config cfg; + struct tile_data tiles; + u64 header; + + header = __get_xsave_xstate_bv((void *)uctxt->uc_mcontext.fpregs); + + if (header & (1 << XFEATURE_XTILE_DATA)) + printf("[FAIL]\ttile data was written in sigframe\n"); + else + printf("[OK]\ttile data was skipped in sigframe\n"); + + set_tilecfg(&cfg); + load_tilecfg(&cfg); + init_xdata(&xdata); + + make_tiles(&tiles); + copy_tiles_to_xdata(&xdata, &tiles); + restore_xdata(&xdata); + + save_xdata(&xdata); + if (compare_xdata_tiles(&xdata, &tiles)) + err(1, "tile load file"); + + printf("\tsignal handler: load tile data\n"); + + sigtrapped = sig; +} + +static void test_signal_handling(void) +{ + struct xsave_data xdata = { 0 }; + struct tile_data tiles = { 0 }; + + sethandler(SIGTRAP, handle_sigtrap, 0); + sigtrapped = 0; + + printf("[RUN]\tCheck tile state management in handling signal\n"); + + printf("\tbefore signal: initial tile data state\n"); + + raise(SIGTRAP); + + if (sigtrapped == 0) + err(1, "sigtrap"); + + save_xdata(&xdata); + if (compare_xdata_tiles(&xdata, &tiles)) { + printf("[FAIL]\ttile data was not loaded at sigreturn\n"); + nerrs++; + } else { + printf("[OK]\ttile data was re-initialized at sigreturn\n"); + } + + clearhandler(SIGTRAP); +} + int main(void) { /* Check hardware availability at first */ @@ -672,6 +737,7 @@ int main(void) test_fork(); test_context_switch(); test_ptrace(); + test_signal_handling(); return nerrs ? 1 : 0; } -- 2.17.1

3 years, 12 months

1
0
0 0

[PATCH v3 19/21] selftest/x86/amx: Include test cases for the AMX state management

by Chang S. Bae

This selftest exercises the kernel's behavior not to inherit AMX state and the ability to switch the context by verifying that they retain unique data between multiple threads. Also, ptrace() is used to insert AMX state into existing threads -- both before and after the existing thread has initialized its AMX state. Collect the test cases of validating those operations together, as they share some common setup for the AMX state. These test cases do not depend on AMX compiler support, as they employ user-space-XSAVE directly to access AMX state. Signed-off-by: Chang S. Bae <chang.seok.bae(a)intel.com> Reviewed-by: Len Brown <len.brown(a)intel.com> Cc: x86(a)kernel.org Cc: linux-kernel(a)vger.kernel.org Cc: linux-kselftest(a)vger.kernel.org --- Changes from v2: * Updated the test messages and the changelog as tile data is not inherited to a child anymore. * Removed bytecode for the instructions already supported by binutils. * Changed to check the XSAVE availability in a reliable way. Changes from v1: * Removed signal testing code --- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/amx.c | 677 +++++++++++++++++++++++++++ 2 files changed, 678 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/amx.c diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 6703c7906b71..8408bbde788f 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -17,7 +17,7 @@ TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer -TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip syscall_numbering +TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip syscall_numbering amx # Some selftests require 32bit support enabled also on 64bit systems TARGETS_C_32BIT_NEEDED := ldt_gdt ptrace_syscall diff --git a/tools/testing/selftests/x86/amx.c b/tools/testing/selftests/x86/amx.c new file mode 100644 index 000000000000..f4ecdfd27ae9 --- /dev/null +++ b/tools/testing/selftests/x86/amx.c @@ -0,0 +1,677 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include <err.h> +#include <elf.h> +#include <pthread.h> +#include <sched.h> +#include <setjmp.h> +#include <signal.h> +#include <stdio.h> +#include <string.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdlib.h> +#include <time.h> +#include <malloc.h> +#include <unistd.h> +#include <ucontext.h> + +#include <linux/futex.h> + +#include <sys/ipc.h> +#include <sys/mman.h> +#include <sys/ptrace.h> +#include <sys/shm.h> +#include <sys/signal.h> +#include <sys/syscall.h> +#include <sys/time.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <sys/uio.h> +#include <sys/ucontext.h> + +#include <x86intrin.h> + +#ifndef __x86_64__ +# error This test is 64-bit only +#endif + +typedef uint8_t u8; +typedef uint16_t u16; +typedef uint32_t u32; +typedef uint64_t u64; + +#define PAGE_SIZE (1 << 12) + +#define NUM_TILES 8 +#define TILE_SIZE 1024 +#define XSAVE_SIZE ((NUM_TILES * TILE_SIZE) + PAGE_SIZE) + +struct xsave_data { + u8 area[XSAVE_SIZE]; +} __attribute__((aligned(64))); + +/* Tile configuration associated: */ +#define MAX_TILES 16 +#define RESERVED_BYTES 14 + +struct tile_config { + u8 palette_id; + u8 start_row; + u8 reserved[RESERVED_BYTES]; + u16 colsb[MAX_TILES]; + u8 rows[MAX_TILES]; +}; + +struct tile_data { + u8 data[NUM_TILES * TILE_SIZE]; +}; + +static inline u64 __xgetbv(u32 index) +{ + u32 eax, edx; + + asm volatile("xgetbv;" + : "=a" (eax), "=d" (edx) + : "c" (index)); + return eax + ((u64)edx << 32); +} + +static inline void __cpuid(u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) +{ + asm volatile("cpuid;" + : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx) + : "0" (*eax), "2" (*ecx)); +} + +/* Load tile configuration */ +static inline void __ldtilecfg(void *cfg) +{ + asm volatile(".byte 0xc4,0xe2,0x78,0x49,0x00" + : : "a"(cfg)); +} + +/* Load tile data to %tmm0 register only */ +static inline void __tileloadd(void *tile) +{ + asm volatile(".byte 0xc4,0xe2,0x7b,0x4b,0x04,0x10" + : : "a"(tile), "d"(0)); +} + +/* Save extended states */ +static inline void __xsave(void *buffer, u32 lo, u32 hi) +{ + asm volatile("xsave (%%rdi)" + : : "D" (buffer), "a" (lo), "d" (hi) + : "memory"); +} + +/* Restore extended states */ +static inline void __xrstor(void *buffer, u32 lo, u32 hi) +{ + asm volatile("xrstor (%%rdi)" + : : "D" (buffer), "a" (lo), "d" (hi)); +} + +/* Release tile states to init values */ +static inline void __tilerelease(void) +{ + asm volatile(".byte 0xc4, 0xe2, 0x78, 0x49, 0xc0" ::); +} + +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"); +} + +/* Hardware info check: */ + +static jmp_buf jmpbuf; +static bool xsave_disabled; + +static void handle_sigill(int sig, siginfo_t *si, void *ctx_void) +{ + xsave_disabled = true; + siglongjmp(jmpbuf, 1); +} + +#define XFEATURE_XTILE_CFG 17 +#define XFEATURE_XTILE_DATA 18 +#define XFEATURE_MASK_XTILE ((1 << XFEATURE_XTILE_DATA) | \ + (1 << XFEATURE_XTILE_CFG)) + +static inline bool check_xsave_supports_xtile(void) +{ + bool supported = false; + + sethandler(SIGILL, handle_sigill, 0); + + if (!sigsetjmp(jmpbuf, 1)) + supported = __xgetbv(0) & XFEATURE_MASK_XTILE; + + clearhandler(SIGILL); + return supported; +} + +struct xtile_hwinfo { + struct { + u16 bytes_per_tile; + u16 bytes_per_row; + u16 max_names; + u16 max_rows; + } spec; + + struct { + u32 offset; + u32 size; + } xsave; +}; + +static struct xtile_hwinfo xtile; + +static bool __enum_xtile_config(void) +{ + u32 eax, ebx, ecx, edx; + u16 bytes_per_tile; + bool valid = false; + +#define TILE_CPUID 0x1d +#define TILE_PALETTE_CPUID_SUBLEAVE 0x1 + + eax = TILE_CPUID; + ecx = TILE_PALETTE_CPUID_SUBLEAVE; + + __cpuid(&eax, &ebx, &ecx, &edx); + if (!eax || !ebx || !ecx) + return valid; + + xtile.spec.max_names = ebx >> 16; + if (xtile.spec.max_names < NUM_TILES) + return valid; + + bytes_per_tile = eax >> 16; + if (bytes_per_tile < TILE_SIZE) + return valid; + + xtile.spec.bytes_per_row = ebx; + xtile.spec.max_rows = ecx; + valid = true; + + return valid; +} + +static bool __enum_xsave_tile(void) +{ + u32 eax, ebx, ecx, edx; + bool valid = false; + +#define XSTATE_CPUID 0xd +#define XSTATE_USER_STATE_SUBLEAVE 0x0 + + eax = XSTATE_CPUID; + ecx = XFEATURE_XTILE_DATA; + + __cpuid(&eax, &ebx, &ecx, &edx); + if (!eax || !ebx) + return valid; + + xtile.xsave.offset = ebx; + xtile.xsave.size = eax; + valid = true; + + return valid; +} + +static bool __check_xsave_size(void) +{ + u32 eax, ebx, ecx, edx; + bool valid = false; + + eax = XSTATE_CPUID; + ecx = XSTATE_USER_STATE_SUBLEAVE; + + __cpuid(&eax, &ebx, &ecx, &edx); + if (ebx && ebx <= XSAVE_SIZE) + valid = true; + + return valid; +} + +/* + * Check the hardware-provided tile state info and cross-check it with the + * hard-coded values: XSAVE_SIZE, NUM_TILES, and TILE_SIZE. + */ +static int check_xtile_hwinfo(void) +{ + bool success = false; + + if (!__check_xsave_size()) + return success; + + if (!__enum_xsave_tile()) + return success; + + if (!__enum_xtile_config()) + return success; + + if (sizeof(struct tile_data) >= xtile.xsave.size) + success = true; + + return success; +} + +/* The helpers for managing XSAVE buffer and tile states: */ + +/* Use the uncompacted format without 'init optimization' */ +static void save_xdata(void *data) +{ + __xsave(data, -1, -1); +} + +static void restore_xdata(void *data) +{ + __xrstor(data, -1, -1); +} + +static inline u64 __get_xsave_xstate_bv(void *data) +{ +#define XSAVE_HDR_OFFSET 512 + return *(u64 *)(data + XSAVE_HDR_OFFSET); +} + +static void set_tilecfg(struct tile_config *cfg) +{ + int i; + + memset(cfg, 0, sizeof(*cfg)); + /* The first implementation has one significant palette with id 1 */ + cfg->palette_id = 1; + for (i = 0; i < xtile.spec.max_names; i++) { + cfg->colsb[i] = xtile.spec.bytes_per_row; + cfg->rows[i] = xtile.spec.max_rows; + } +} + +static void load_tilecfg(struct tile_config *cfg) +{ + __ldtilecfg(cfg); +} + +static void make_tiles(void *tiles) +{ + u32 iterations = xtile.xsave.size / sizeof(u32); + static u32 value = 1; + u32 *ptr = tiles; + int i; + + for (i = 0, ptr = tiles; i < iterations; i++, ptr++) + *ptr = value; + value++; +} + +/* + * Initialize the XSAVE buffer: + * + * Make sure tile configuration loaded already. Load limited tile data (%tmm0 only) + * and save all the states. XSAVE buffer is ready to complete tile data. + */ +static void init_xdata(void *data) +{ + struct tile_data tiles; + + make_tiles(&tiles); + __tileloadd(&tiles); + __xsave(data, -1, -1); +} + +static inline void *__get_xsave_tile_data_addr(void *data) +{ + return data + xtile.xsave.offset; +} + +static void copy_tiles_to_xdata(void *xdata, void *tiles) +{ + void *dst = __get_xsave_tile_data_addr(xdata); + + memcpy(dst, tiles, xtile.xsave.size); +} + +static int compare_xdata_tiles(void *xdata, void *tiles) +{ + void *tile_data = __get_xsave_tile_data_addr(xdata); + + if (memcmp(tile_data, tiles, xtile.xsave.size)) + return 1; + + return 0; +} + +static int nerrs, errs; + +/* Testing tile data inheritance */ + +static void test_tile_data_inheritance(void) +{ + struct xsave_data xdata; + struct tile_data tiles; + struct tile_config cfg; + pid_t child; + int status; + + set_tilecfg(&cfg); + load_tilecfg(&cfg); + init_xdata(&xdata); + + make_tiles(&tiles); + copy_tiles_to_xdata(&xdata, &tiles); + restore_xdata(&xdata); + + errs = 0; + + child = fork(); + if (child < 0) + err(1, "fork"); + + if (child == 0) { + memset(&xdata, 0, sizeof(xdata)); + save_xdata(&xdata); + if (compare_xdata_tiles(&xdata, &tiles)) { + printf("[OK]\tchild didn't inherit tile data at fork()\n"); + } else { + printf("[FAIL]\tchild inherited tile data at fork()\n"); + nerrs++; + } + _exit(0); + } + wait(&status); +} + +static void test_fork(void) +{ + pid_t child; + int status; + + child = fork(); + if (child < 0) + err(1, "fork"); + + if (child == 0) { + test_tile_data_inheritance(); + _exit(0); + } + + wait(&status); +} + +/* Context switching test */ + +#define ITERATIONS 10 +#define NUM_THREADS 5 + +struct futex_info { + int current; + int next; + int *futex; +}; + +static inline void command_wait(struct futex_info *info, int value) +{ + do { + sched_yield(); + } while (syscall(SYS_futex, info->futex, FUTEX_WAIT, value, 0, 0, 0)); +} + +static inline void command_wake(struct futex_info *info, int value) +{ + do { + *info->futex = value; + while (!syscall(SYS_futex, info->futex, FUTEX_WAKE, 1, 0, 0, 0)) + sched_yield(); + } while (0); +} + +static inline int get_iterative_value(int id) +{ + return ((id << 1) & ~0x1); +} + +static inline int get_endpoint_value(int id) +{ + return ((id << 1) | 0x1); +} + +static void *check_tiles(void *info) +{ + struct futex_info *finfo = (struct futex_info *)info; + struct xsave_data xdata; + struct tile_data tiles; + struct tile_config cfg; + int i; + + set_tilecfg(&cfg); + load_tilecfg(&cfg); + init_xdata(&xdata); + + make_tiles(&tiles); + copy_tiles_to_xdata(&xdata, &tiles); + restore_xdata(&xdata); + + for (i = 0; i < ITERATIONS; i++) { + command_wait(finfo, get_iterative_value(finfo->current)); + + memset(&xdata, 0, sizeof(xdata)); + save_xdata(&xdata); + errs += compare_xdata_tiles(&xdata, &tiles); + + make_tiles(&tiles); + copy_tiles_to_xdata(&xdata, &tiles); + restore_xdata(&xdata); + + command_wake(finfo, get_iterative_value(finfo->next)); + } + + command_wait(finfo, get_endpoint_value(finfo->current)); + __tilerelease(); + return NULL; +} + +static int create_children(int num, struct futex_info *finfo) +{ + const int shm_id = shmget(IPC_PRIVATE, sizeof(int), IPC_CREAT | 0666); + int *futex = shmat(shm_id, NULL, 0); + pthread_t thread; + int i; + + for (i = 0; i < num; i++) { + finfo[i].futex = futex; + finfo[i].current = i + 1; + finfo[i].next = (i + 2) % (num + 1); + + if (pthread_create(&thread, NULL, check_tiles, &finfo[i])) { + err(1, "pthread_create"); + return 1; + } + } + return 0; +} + +static void test_context_switch(void) +{ + struct futex_info *finfo; + cpu_set_t cpuset; + int i; + + printf("[RUN]\t%u context switches of tile states in %d threads\n", + ITERATIONS * NUM_THREADS, NUM_THREADS); + + errs = 0; + + CPU_ZERO(&cpuset); + CPU_SET(0, &cpuset); + if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) + err(1, "sched_setaffinity to CPU 0"); + + finfo = malloc(sizeof(*finfo) * NUM_THREADS); + + if (create_children(NUM_THREADS, finfo)) + return; + + for (i = 0; i < ITERATIONS; i++) { + command_wake(finfo, get_iterative_value(1)); + command_wait(finfo, get_iterative_value(0)); + } + + for (i = 1; i <= NUM_THREADS; i++) + command_wake(finfo, get_endpoint_value(i)); + + if (errs) { + printf("[FAIL]\t%u incorrect tile states\n", errs); + nerrs += errs; + return; + } + + printf("[OK]\tall tile states are correct\n"); +} + +/* Ptrace test */ + +static inline long get_tile_state(pid_t child, struct iovec *iov) +{ + return ptrace(PTRACE_GETREGSET, child, (u32)NT_X86_XSTATE, iov); +} + +static inline long set_tile_state(pid_t child, struct iovec *iov) +{ + return ptrace(PTRACE_SETREGSET, child, (u32)NT_X86_XSTATE, iov); +} + +static int write_tile_state(bool load_tile, pid_t child) +{ + struct xsave_data xdata; + struct tile_data tiles; + struct iovec iov; + + iov.iov_base = &xdata; + iov.iov_len = sizeof(xdata); + + if (get_tile_state(child, &iov)) + err(1, "PTRACE_GETREGSET"); + + make_tiles(&tiles); + copy_tiles_to_xdata(&xdata, &tiles); + if (set_tile_state(child, &iov)) + err(1, "PTRACE_SETREGSET"); + + memset(&xdata, 0, sizeof(xdata)); + if (get_tile_state(child, &iov)) + err(1, "PTRACE_GETREGSET"); + + if (!load_tile) + memset(&tiles, 0, sizeof(tiles)); + + return compare_xdata_tiles(&xdata, &tiles); +} + +static void test_tile_state_write(bool load_tile) +{ + pid_t child; + int status; + + child = fork(); + if (child < 0) + err(1, "fork"); + + if (child == 0) { + printf("[RUN]\tPtrace-induced tile state write, "); + printf("%s tile data loaded\n", load_tile ? "with" : "without"); + + if (ptrace(PTRACE_TRACEME, 0, NULL, NULL)) + err(1, "PTRACE_TRACEME"); + + if (load_tile) { + struct tile_config cfg; + struct tile_data tiles; + + set_tilecfg(&cfg); + load_tilecfg(&cfg); + make_tiles(&tiles); + /* Load only %tmm0 but inducing the #NM */ + __tileloadd(&tiles); + } + + raise(SIGTRAP); + _exit(0); + } + + do { + wait(&status); + } while (WSTOPSIG(status) != SIGTRAP); + + errs = write_tile_state(load_tile, child); + if (errs) { + nerrs++; + printf("[FAIL]\t%s write\n", load_tile ? "incorrect" : "unexpected"); + } else { + printf("[OK]\t%s write\n", load_tile ? "correct" : "no"); + } + + ptrace(PTRACE_DETACH, child, NULL, NULL); + wait(&status); +} + +static void test_ptrace(void) +{ + bool ptracee_loads_tiles; + + ptracee_loads_tiles = true; + test_tile_state_write(ptracee_loads_tiles); + + ptracee_loads_tiles = false; + test_tile_state_write(ptracee_loads_tiles); +} + +int main(void) +{ + /* Check hardware availability at first */ + + if (!check_xsave_supports_xtile()) { + if (xsave_disabled) + printf("XSAVE disabled.\n"); + else + printf("Tile data not available.\n"); + return 0; + } + + if (!check_xtile_hwinfo()) { + printf("Available tile state size is insufficient to test.\n"); + return 0; + } + + nerrs = 0; + + test_fork(); + test_context_switch(); + test_ptrace(); + + return nerrs ? 1 : 0; +} -- 2.17.1

3 years, 12 months

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[PATCH AUTOSEL 4.9 29/48] selftests/x86/fsgsbase: Fix GS == 1, 2, and 3 tests

by Sasha Levin

From: Andy Lutomirski <luto(a)kernel.org> [ Upstream commit 716572b0003ef67a4889bd7d85baf5099c5a0248 ] Setting GS to 1, 2, or 3 causes a nonsensical part of the IRET microcode to change GS back to zero on a return from kernel mode to user mode. The result is that these tests fail randomly depending on when interrupts happen. Detect when this happens and let the test pass. Signed-off-by: Andy Lutomirski <luto(a)kernel.org> Signed-off-by: Borislav Petkov <bp(a)suse.de> Link: https://lkml.kernel.org/r/7567fd44a1d60a9424f25b19a998f12149993b0d.16043465… Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/testing/selftests/x86/fsgsbase.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/x86/fsgsbase.c b/tools/testing/selftests/x86/fsgsbase.c index f249e042b3b51..026cd644360f6 100644 --- a/tools/testing/selftests/x86/fsgsbase.c +++ b/tools/testing/selftests/x86/fsgsbase.c @@ -318,8 +318,8 @@ static void set_gs_and_switch_to(unsigned long local, local = read_base(GS); /* - * Signal delivery seems to mess up weird selectors. Put it - * back. + * Signal delivery is quite likely to change a selector + * of 1, 2, or 3 back to 0 due to IRET being defective. */ asm volatile ("mov %0, %%gs" : : "rm" (force_sel)); } else { @@ -337,6 +337,14 @@ static void set_gs_and_switch_to(unsigned long local, if (base == local && sel_pre_sched == sel_post_sched) { printf("[OK]\tGS/BASE remained 0x%hx/0x%lx\n", sel_pre_sched, local); + } else if (base == local && sel_pre_sched >= 1 && sel_pre_sched <= 3 && + sel_post_sched == 0) { + /* + * IRET is misdesigned and will squash selectors 1, 2, or 3 + * to zero. Don't fail the test just because this happened. + */ + printf("[OK]\tGS/BASE changed from 0x%hx/0x%lx to 0x%hx/0x%lx because IRET is defective\n", + sel_pre_sched, local, sel_post_sched, base); } else { nerrs++; printf("[FAIL]\tGS/BASE changed from 0x%hx/0x%lx to 0x%hx/0x%lx\n", -- 2.27.0

3 years, 12 months

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[PATCH AUTOSEL 4.14 38/66] selftests/x86/fsgsbase: Fix GS == 1, 2, and 3 tests

by Sasha Levin

From: Andy Lutomirski <luto(a)kernel.org> [ Upstream commit 716572b0003ef67a4889bd7d85baf5099c5a0248 ] Setting GS to 1, 2, or 3 causes a nonsensical part of the IRET microcode to change GS back to zero on a return from kernel mode to user mode. The result is that these tests fail randomly depending on when interrupts happen. Detect when this happens and let the test pass. Signed-off-by: Andy Lutomirski <luto(a)kernel.org> Signed-off-by: Borislav Petkov <bp(a)suse.de> Link: https://lkml.kernel.org/r/7567fd44a1d60a9424f25b19a998f12149993b0d.16043465… Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/testing/selftests/x86/fsgsbase.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/x86/fsgsbase.c b/tools/testing/selftests/x86/fsgsbase.c index f249e042b3b51..026cd644360f6 100644 --- a/tools/testing/selftests/x86/fsgsbase.c +++ b/tools/testing/selftests/x86/fsgsbase.c @@ -318,8 +318,8 @@ static void set_gs_and_switch_to(unsigned long local, local = read_base(GS); /* - * Signal delivery seems to mess up weird selectors. Put it - * back. + * Signal delivery is quite likely to change a selector + * of 1, 2, or 3 back to 0 due to IRET being defective. */ asm volatile ("mov %0, %%gs" : : "rm" (force_sel)); } else { @@ -337,6 +337,14 @@ static void set_gs_and_switch_to(unsigned long local, if (base == local && sel_pre_sched == sel_post_sched) { printf("[OK]\tGS/BASE remained 0x%hx/0x%lx\n", sel_pre_sched, local); + } else if (base == local && sel_pre_sched >= 1 && sel_pre_sched <= 3 && + sel_post_sched == 0) { + /* + * IRET is misdesigned and will squash selectors 1, 2, or 3 + * to zero. Don't fail the test just because this happened. + */ + printf("[OK]\tGS/BASE changed from 0x%hx/0x%lx to 0x%hx/0x%lx because IRET is defective\n", + sel_pre_sched, local, sel_post_sched, base); } else { nerrs++; printf("[FAIL]\tGS/BASE changed from 0x%hx/0x%lx to 0x%hx/0x%lx\n", -- 2.27.0

3 years, 12 months

1
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[PATCH AUTOSEL 4.19 45/87] selftests/x86/fsgsbase: Fix GS == 1, 2, and 3 tests

by Sasha Levin

From: Andy Lutomirski <luto(a)kernel.org> [ Upstream commit 716572b0003ef67a4889bd7d85baf5099c5a0248 ] Setting GS to 1, 2, or 3 causes a nonsensical part of the IRET microcode to change GS back to zero on a return from kernel mode to user mode. The result is that these tests fail randomly depending on when interrupts happen. Detect when this happens and let the test pass. Signed-off-by: Andy Lutomirski <luto(a)kernel.org> Signed-off-by: Borislav Petkov <bp(a)suse.de> Link: https://lkml.kernel.org/r/7567fd44a1d60a9424f25b19a998f12149993b0d.16043465… Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/testing/selftests/x86/fsgsbase.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/x86/fsgsbase.c b/tools/testing/selftests/x86/fsgsbase.c index f249e042b3b51..026cd644360f6 100644 --- a/tools/testing/selftests/x86/fsgsbase.c +++ b/tools/testing/selftests/x86/fsgsbase.c @@ -318,8 +318,8 @@ static void set_gs_and_switch_to(unsigned long local, local = read_base(GS); /* - * Signal delivery seems to mess up weird selectors. Put it - * back. + * Signal delivery is quite likely to change a selector + * of 1, 2, or 3 back to 0 due to IRET being defective. */ asm volatile ("mov %0, %%gs" : : "rm" (force_sel)); } else { @@ -337,6 +337,14 @@ static void set_gs_and_switch_to(unsigned long local, if (base == local && sel_pre_sched == sel_post_sched) { printf("[OK]\tGS/BASE remained 0x%hx/0x%lx\n", sel_pre_sched, local); + } else if (base == local && sel_pre_sched >= 1 && sel_pre_sched <= 3 && + sel_post_sched == 0) { + /* + * IRET is misdesigned and will squash selectors 1, 2, or 3 + * to zero. Don't fail the test just because this happened. + */ + printf("[OK]\tGS/BASE changed from 0x%hx/0x%lx to 0x%hx/0x%lx because IRET is defective\n", + sel_pre_sched, local, sel_post_sched, base); } else { nerrs++; printf("[FAIL]\tGS/BASE changed from 0x%hx/0x%lx to 0x%hx/0x%lx\n", -- 2.27.0

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Linux-kselftest-mirror December 2020