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Diffstat (limited to 'test/syscalls/linux/fpsig_nested.cc')
-rw-r--r-- | test/syscalls/linux/fpsig_nested.cc | 134 |
1 files changed, 0 insertions, 134 deletions
diff --git a/test/syscalls/linux/fpsig_nested.cc b/test/syscalls/linux/fpsig_nested.cc deleted file mode 100644 index c476a8e7a..000000000 --- a/test/syscalls/linux/fpsig_nested.cc +++ /dev/null @@ -1,134 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -// This program verifies that application floating point state is restored -// correctly after a signal handler returns. It also verifies that this works -// with nested signals. -#include <sys/time.h> - -#include "gtest/gtest.h" -#include "test/util/test_util.h" -#include "test/util/thread_util.h" - -namespace gvisor { -namespace testing { - -namespace { - -#define GET_XMM(__var, __xmm) \ - asm volatile("movq %%" #__xmm ", %0" : "=r"(__var)) -#define SET_XMM(__var, __xmm) asm volatile("movq %0, %%" #__xmm : : "r"(__var)) - -int pid; -int tid; - -volatile uint64_t entryxmm[2] = {~0UL, ~0UL}; -volatile uint64_t exitxmm[2]; - -void sigusr2(int s, siginfo_t* siginfo, void* _uc) { - uint64_t val = SIGUSR2; - - // Record the value of %xmm0 on entry and then clobber it. - GET_XMM(entryxmm[1], xmm0); - SET_XMM(val, xmm0); - GET_XMM(exitxmm[1], xmm0); -} - -void sigusr1(int s, siginfo_t* siginfo, void* _uc) { - uint64_t val = SIGUSR1; - - // Record the value of %xmm0 on entry and then clobber it. - GET_XMM(entryxmm[0], xmm0); - SET_XMM(val, xmm0); - - // Send a SIGUSR2 to ourself. The signal mask is configured such that - // the SIGUSR2 handler will run before this handler returns. - asm volatile( - "movl %[killnr], %%eax;" - "movl %[pid], %%edi;" - "movl %[tid], %%esi;" - "movl %[sig], %%edx;" - "syscall;" - : - : [ killnr ] "i"(__NR_tgkill), [ pid ] "rm"(pid), [ tid ] "rm"(tid), - [ sig ] "i"(SIGUSR2) - : "rax", "rdi", "rsi", "rdx", - // Clobbered by syscall. - "rcx", "r11"); - - // Record value of %xmm0 again to verify that the nested signal handler - // does not clobber it. - GET_XMM(exitxmm[0], xmm0); -} - -TEST(FPSigTest, NestedSignals) { - pid = getpid(); - tid = gettid(); - - struct sigaction sa = {}; - sigemptyset(&sa.sa_mask); - sa.sa_flags = SA_SIGINFO; - sa.sa_sigaction = sigusr1; - ASSERT_THAT(sigaction(SIGUSR1, &sa, nullptr), SyscallSucceeds()); - - sa.sa_sigaction = sigusr2; - ASSERT_THAT(sigaction(SIGUSR2, &sa, nullptr), SyscallSucceeds()); - - // The amd64 ABI specifies that the XMM register set is caller-saved. This - // implies that if there is any function call between SET_XMM and GET_XMM the - // compiler might save/restore xmm0 implicitly. This defeats the entire - // purpose of the test which is to verify that fpstate is restored by - // sigreturn(2). - // - // This is the reason why 'tgkill(getpid(), gettid(), SIGUSR1)' is implemented - // in inline assembly below. - // - // If the OS is broken and registers are clobbered by the signal, using tgkill - // to signal the current thread ensures that this is the clobbered thread. - - uint64_t expected = 0xdeadbeeffacefeed; - SET_XMM(expected, xmm0); - - asm volatile( - "movl %[killnr], %%eax;" - "movl %[pid], %%edi;" - "movl %[tid], %%esi;" - "movl %[sig], %%edx;" - "syscall;" - : - : [ killnr ] "i"(__NR_tgkill), [ pid ] "rm"(pid), [ tid ] "rm"(tid), - [ sig ] "i"(SIGUSR1) - : "rax", "rdi", "rsi", "rdx", - // Clobbered by syscall. - "rcx", "r11"); - - uint64_t got; - GET_XMM(got, xmm0); - - // - // The checks below verifies the following: - // - signal handlers must called with a clean fpu state. - // - sigreturn(2) must restore fpstate of the interrupted context. - // - EXPECT_EQ(expected, got); - EXPECT_EQ(entryxmm[0], 0); - EXPECT_EQ(entryxmm[1], 0); - EXPECT_EQ(exitxmm[0], SIGUSR1); - EXPECT_EQ(exitxmm[1], SIGUSR2); -} - -} // namespace - -} // namespace testing -} // namespace gvisor |