| 1 | //===-- Unittests for sigaltstack -----------------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "hdr/signal_macros.h" |
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| 10 | #include "src/__support/OSUtil/syscall.h" // For internal syscall function. |
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| 11 | #include "src/__support/libc_errno.h" |
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| 12 | #include "src/signal/linux/signal_utils.h" |
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| 13 | #include "src/signal/raise.h" |
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| 14 | #include "src/signal/sigaction.h" |
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| 15 | #include "src/signal/sigaltstack.h" |
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| 16 | #include "test/UnitTest/ErrnoSetterMatcher.h" |
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| 17 | #include "test/UnitTest/Test.h" |
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| 18 | |
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| 19 | #include <stdint.h> |
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| 20 | #include <sys/syscall.h> |
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| 21 | |
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| 22 | constexpr int LOCAL_VAR_SIZE = 512; |
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| 23 | constexpr int ALT_STACK_SIZE = SIGSTKSZ + LOCAL_VAR_SIZE * 2; |
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| 24 | static uint8_t alt_stack[ALT_STACK_SIZE]; |
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| 25 | |
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| 26 | using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails; |
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| 27 | using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds; |
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| 28 | |
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| 29 | static bool good_stack; |
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| 30 | static void handler(int) { |
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| 31 | // Allocate a large stack variable so that it does not get optimized |
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| 32 | // out or mapped to a register. |
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| 33 | uint8_t var[LOCAL_VAR_SIZE]; |
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| 34 | for (int i = 0; i < LOCAL_VAR_SIZE; ++i) |
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| 35 | var[i] = i; |
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| 36 | // Verify that array is completely on the alt_stack. |
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| 37 | for (int i = 0; i < LOCAL_VAR_SIZE; ++i) { |
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| 38 | if (!(uintptr_t(var + i) < uintptr_t(alt_stack + ALT_STACK_SIZE) && |
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| 39 | uintptr_t(alt_stack) <= uintptr_t(var + i))) { |
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| 40 | good_stack = false; |
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| 41 | return; |
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| 42 | } |
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| 43 | } |
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| 44 | good_stack = true; |
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| 45 | } |
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| 46 | |
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| 47 | TEST(LlvmLibcSignalTest, SigaltstackRunOnAltStack) { |
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| 48 | struct sigaction action; |
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| 49 | libc_errno = 0; |
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| 50 | ASSERT_THAT(LIBC_NAMESPACE::sigaction(SIGUSR1, nullptr, &action), |
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| 51 | Succeeds(0)); |
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| 52 | action.sa_handler = handler; |
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| 53 | // Indicate that the signal should be delivered on an alternate stack. |
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| 54 | action.sa_flags = SA_ONSTACK; |
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| 55 | ASSERT_THAT(LIBC_NAMESPACE::sigaction(SIGUSR1, &action, nullptr), |
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| 56 | Succeeds(0)); |
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| 57 | |
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| 58 | stack_t ss; |
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| 59 | ss.ss_sp = alt_stack; |
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| 60 | ss.ss_size = ALT_STACK_SIZE; |
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| 61 | ss.ss_flags = 0; |
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| 62 | // Setup the alternate stack. |
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| 63 | ASSERT_THAT(LIBC_NAMESPACE::sigaltstack(&ss, nullptr), Succeeds(0)); |
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| 64 | |
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| 65 | good_stack = false; |
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| 66 | LIBC_NAMESPACE::raise(SIGUSR1); |
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| 67 | EXPECT_TRUE(good_stack); |
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| 68 | } |
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| 69 | |
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| 70 | // This tests for invalid input. |
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| 71 | TEST(LlvmLibcSignalTest, SigaltstackInvalidStack) { |
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| 72 | stack_t ss; |
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| 73 | ss.ss_sp = alt_stack; |
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| 74 | ss.ss_size = 0; |
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| 75 | ss.ss_flags = SS_ONSTACK; |
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| 76 | ASSERT_THAT(LIBC_NAMESPACE::sigaltstack(&ss, nullptr), Fails(EINVAL)); |
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| 77 | |
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| 78 | ss.ss_flags = 0; |
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| 79 | ASSERT_THAT(LIBC_NAMESPACE::sigaltstack(&ss, nullptr), Fails(ENOMEM)); |
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| 80 | } |
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| 81 | |
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