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-rw-r--r--test/syscalls/linux/BUILD5
-rw-r--r--test/syscalls/linux/aio.cc155
-rw-r--r--test/syscalls/linux/mremap.cc11
-rw-r--r--test/util/memory_util.h12
4 files changed, 89 insertions, 94 deletions
diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD
index a964bef24..c67ceddb6 100644
--- a/test/syscalls/linux/BUILD
+++ b/test/syscalls/linux/BUILD
@@ -265,12 +265,15 @@ cc_binary(
],
linkstatic = 1,
deps = [
- # The heap check doesn't handle mremap properly.
+ # The heapchecker doesn't recognize that io_destroy munmaps.
"@com_google_googletest//:gtest",
"@com_google_absl//absl/strings",
"//test/util:cleanup",
"//test/util:file_descriptor",
+ "//test/util:fs_util",
+ "//test/util:memory_util",
"//test/util:posix_error",
+ "//test/util:proc_util",
"//test/util:temp_path",
"//test/util:test_main",
"//test/util:test_util",
diff --git a/test/syscalls/linux/aio.cc b/test/syscalls/linux/aio.cc
index 68dc05417..b27d4e10a 100644
--- a/test/syscalls/linux/aio.cc
+++ b/test/syscalls/linux/aio.cc
@@ -14,31 +14,57 @@
#include <fcntl.h>
#include <linux/aio_abi.h>
-#include <string.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
+#include <algorithm>
+#include <string>
+
#include "gtest/gtest.h"
#include "test/syscalls/linux/file_base.h"
#include "test/util/cleanup.h"
#include "test/util/file_descriptor.h"
+#include "test/util/fs_util.h"
+#include "test/util/memory_util.h"
+#include "test/util/posix_error.h"
+#include "test/util/proc_util.h"
#include "test/util/temp_path.h"
#include "test/util/test_util.h"
+using ::testing::_;
+
namespace gvisor {
namespace testing {
namespace {
+// Returns the size of the VMA containing the given address.
+PosixErrorOr<size_t> VmaSizeAt(uintptr_t addr) {
+ ASSIGN_OR_RETURN_ERRNO(std::string proc_self_maps,
+ GetContents("/proc/self/maps"));
+ ASSIGN_OR_RETURN_ERRNO(auto entries, ParseProcMaps(proc_self_maps));
+ // Use binary search to find the first VMA that might contain addr.
+ ProcMapsEntry target = {};
+ target.end = addr;
+ auto it =
+ std::upper_bound(entries.begin(), entries.end(), target,
+ [](const ProcMapsEntry& x, const ProcMapsEntry& y) {
+ return x.end < y.end;
+ });
+ // Check that it actually contains addr.
+ if (it == entries.end() || addr < it->start) {
+ return PosixError(ENOENT, absl::StrCat("no VMA contains address ", addr));
+ }
+ return it->end - it->start;
+}
+
constexpr char kData[] = "hello world!";
int SubmitCtx(aio_context_t ctx, long nr, struct iocb** iocbpp) {
return syscall(__NR_io_submit, ctx, nr, iocbpp);
}
-} // namespace
-
class AIOTest : public FileTest {
public:
AIOTest() : ctx_(0) {}
@@ -124,10 +150,10 @@ TEST_F(AIOTest, BasicWrite) {
EXPECT_EQ(events[0].res, strlen(kData));
// Verify that the file contains the contents.
- char verify_buf[32] = {};
- ASSERT_THAT(read(test_file_fd_.get(), &verify_buf[0], strlen(kData)),
- SyscallSucceeds());
- EXPECT_EQ(strcmp(kData, &verify_buf[0]), 0);
+ char verify_buf[sizeof(kData)] = {};
+ ASSERT_THAT(read(test_file_fd_.get(), verify_buf, sizeof(kData)),
+ SyscallSucceedsWithValue(strlen(kData)));
+ EXPECT_STREQ(verify_buf, kData);
}
TEST_F(AIOTest, BadWrite) {
@@ -220,38 +246,25 @@ TEST_F(AIOTest, CloneVm) {
TEST_F(AIOTest, Mremap) {
// Setup a context that is 128 entries deep.
ASSERT_THAT(SetupContext(128), SyscallSucceeds());
+ const size_t ctx_size =
+ ASSERT_NO_ERRNO_AND_VALUE(VmaSizeAt(reinterpret_cast<uintptr_t>(ctx_)));
struct iocb cb = CreateCallback();
struct iocb* cbs[1] = {&cb};
// Reserve address space for the mremap target so we have something safe to
// map over.
- //
- // N.B. We reserve 2 pages because we'll attempt to remap to 2 pages below.
- // That should fail with EFAULT, but will fail with EINVAL if this mmap
- // returns the page immediately below ctx_, as
- // [new_address, new_address+2*kPageSize) overlaps [ctx_, ctx_+kPageSize).
- void* new_address = mmap(nullptr, 2 * kPageSize, PROT_READ,
- MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
- ASSERT_THAT(reinterpret_cast<intptr_t>(new_address), SyscallSucceeds());
- auto mmap_cleanup = Cleanup([new_address] {
- EXPECT_THAT(munmap(new_address, 2 * kPageSize), SyscallSucceeds());
- });
-
- // Test that remapping to a larger address fails.
- void* res = mremap(reinterpret_cast<void*>(ctx_), kPageSize, 2 * kPageSize,
- MREMAP_FIXED | MREMAP_MAYMOVE, new_address);
- ASSERT_THAT(reinterpret_cast<intptr_t>(res), SyscallFailsWithErrno(EFAULT));
+ Mapping dst =
+ ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(ctx_size, PROT_READ, MAP_PRIVATE));
// Remap context 'handle' to a different address.
- res = mremap(reinterpret_cast<void*>(ctx_), kPageSize, kPageSize,
- MREMAP_FIXED | MREMAP_MAYMOVE, new_address);
- ASSERT_THAT(
- reinterpret_cast<intptr_t>(res),
- SyscallSucceedsWithValue(reinterpret_cast<intptr_t>(new_address)));
- mmap_cleanup.Release();
+ ASSERT_THAT(Mremap(reinterpret_cast<void*>(ctx_), ctx_size, dst.len(),
+ MREMAP_FIXED | MREMAP_MAYMOVE, dst.ptr()),
+ IsPosixErrorOkAndHolds(dst.ptr()));
aio_context_t old_ctx = ctx_;
- ctx_ = reinterpret_cast<aio_context_t>(new_address);
+ ctx_ = reinterpret_cast<aio_context_t>(dst.addr());
+ // io_destroy() will unmap dst now.
+ dst.release();
// Check that submitting the request with the old 'ctx_' fails.
ASSERT_THAT(SubmitCtx(old_ctx, 1, cbs), SyscallFailsWithErrno(EINVAL));
@@ -260,18 +273,12 @@ TEST_F(AIOTest, Mremap) {
ASSERT_THAT(Submit(1, cbs), SyscallSucceedsWithValue(1));
// Remap again.
- new_address =
- mmap(nullptr, kPageSize, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
- ASSERT_THAT(reinterpret_cast<int64_t>(new_address), SyscallSucceeds());
- auto mmap_cleanup2 = Cleanup([new_address] {
- EXPECT_THAT(munmap(new_address, kPageSize), SyscallSucceeds());
- });
- res = mremap(reinterpret_cast<void*>(ctx_), kPageSize, kPageSize,
- MREMAP_FIXED | MREMAP_MAYMOVE, new_address);
- ASSERT_THAT(reinterpret_cast<int64_t>(res),
- SyscallSucceedsWithValue(reinterpret_cast<int64_t>(new_address)));
- mmap_cleanup2.Release();
- ctx_ = reinterpret_cast<aio_context_t>(new_address);
+ dst = ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(ctx_size, PROT_READ, MAP_PRIVATE));
+ ASSERT_THAT(Mremap(reinterpret_cast<void*>(ctx_), ctx_size, dst.len(),
+ MREMAP_FIXED | MREMAP_MAYMOVE, dst.ptr()),
+ IsPosixErrorOkAndHolds(dst.ptr()));
+ ctx_ = reinterpret_cast<aio_context_t>(dst.addr());
+ dst.release();
// Get the reply with yet another 'ctx_' and verify it.
struct io_event events[1];
@@ -281,51 +288,33 @@ TEST_F(AIOTest, Mremap) {
EXPECT_EQ(events[0].res, strlen(kData));
// Verify that the file contains the contents.
- char verify_buf[32] = {};
- ASSERT_THAT(read(test_file_fd_.get(), &verify_buf[0], strlen(kData)),
- SyscallSucceeds());
- EXPECT_EQ(strcmp(kData, &verify_buf[0]), 0);
+ char verify_buf[sizeof(kData)] = {};
+ ASSERT_THAT(read(test_file_fd_.get(), verify_buf, sizeof(kData)),
+ SyscallSucceedsWithValue(strlen(kData)));
+ EXPECT_STREQ(verify_buf, kData);
}
-// Tests that AIO context can be replaced with a different mapping at the same
-// address and continue working. Don't ask why, but Linux allows it.
-TEST_F(AIOTest, MremapOver) {
+// Tests that AIO context cannot be expanded with mremap.
+TEST_F(AIOTest, MremapExpansion) {
// Setup a context that is 128 entries deep.
ASSERT_THAT(SetupContext(128), SyscallSucceeds());
+ const size_t ctx_size =
+ ASSERT_NO_ERRNO_AND_VALUE(VmaSizeAt(reinterpret_cast<uintptr_t>(ctx_)));
- struct iocb cb = CreateCallback();
- struct iocb* cbs[1] = {&cb};
-
- ASSERT_THAT(Submit(1, cbs), SyscallSucceedsWithValue(1));
-
- // Allocate a new VMA, copy 'ctx_' content over, and remap it on top
- // of 'ctx_'.
- void* new_address = mmap(nullptr, kPageSize, PROT_READ | PROT_WRITE,
- MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
- ASSERT_THAT(reinterpret_cast<int64_t>(new_address), SyscallSucceeds());
- auto mmap_cleanup = Cleanup([new_address] {
- EXPECT_THAT(munmap(new_address, kPageSize), SyscallSucceeds());
- });
-
- memcpy(new_address, reinterpret_cast<void*>(ctx_), kPageSize);
- void* res =
- mremap(new_address, kPageSize, kPageSize, MREMAP_FIXED | MREMAP_MAYMOVE,
- reinterpret_cast<void*>(ctx_));
- ASSERT_THAT(reinterpret_cast<int64_t>(res), SyscallSucceedsWithValue(ctx_));
- mmap_cleanup.Release();
-
- // Everything continues to work just fine.
- struct io_event events[1];
- ASSERT_THAT(GetEvents(1, 1, events, nullptr), SyscallSucceedsWithValue(1));
- EXPECT_EQ(events[0].data, 0x123);
- EXPECT_EQ(events[0].obj, reinterpret_cast<long>(&cb));
- EXPECT_EQ(events[0].res, strlen(kData));
-
- // Verify that the file contains the contents.
- char verify_buf[32] = {};
- ASSERT_THAT(read(test_file_fd_.get(), &verify_buf[0], strlen(kData)),
- SyscallSucceeds());
- EXPECT_EQ(strcmp(kData, &verify_buf[0]), 0);
+ // Reserve address space for the mremap target so we have something safe to
+ // map over.
+ Mapping dst = ASSERT_NO_ERRNO_AND_VALUE(
+ MmapAnon(ctx_size + kPageSize, PROT_NONE, MAP_PRIVATE));
+
+ // Test that remapping to a larger address range fails.
+ ASSERT_THAT(Mremap(reinterpret_cast<void*>(ctx_), ctx_size, dst.len(),
+ MREMAP_FIXED | MREMAP_MAYMOVE, dst.ptr()),
+ PosixErrorIs(EFAULT, _));
+
+ // mm/mremap.c:sys_mremap() => mremap_to() does do_munmap() of the destination
+ // before it hits the VM_DONTEXPAND check in vma_to_resize(), so we should no
+ // longer munmap it (another thread may have created a mapping there).
+ dst.release();
}
// Tests that AIO calls fail if context's address is inaccessible.
@@ -429,5 +418,7 @@ TEST_P(AIOVectorizedParamTest, BadIOVecs) {
INSTANTIATE_TEST_SUITE_P(BadIOVecs, AIOVectorizedParamTest,
::testing::Values(IOCB_CMD_PREADV, IOCB_CMD_PWRITEV));
+} // namespace
+
} // namespace testing
} // namespace gvisor
diff --git a/test/syscalls/linux/mremap.cc b/test/syscalls/linux/mremap.cc
index 64e435cb7..f0e5f7d82 100644
--- a/test/syscalls/linux/mremap.cc
+++ b/test/syscalls/linux/mremap.cc
@@ -35,17 +35,6 @@ namespace testing {
namespace {
-// Wrapper for mremap that returns a PosixErrorOr<>, since the return type of
-// void* isn't directly compatible with SyscallSucceeds.
-PosixErrorOr<void*> Mremap(void* old_address, size_t old_size, size_t new_size,
- int flags, void* new_address) {
- void* rv = mremap(old_address, old_size, new_size, flags, new_address);
- if (rv == MAP_FAILED) {
- return PosixError(errno, "mremap failed");
- }
- return rv;
-}
-
// Fixture for mremap tests parameterized by mmap flags.
using MremapParamTest = ::testing::TestWithParam<int>;
diff --git a/test/util/memory_util.h b/test/util/memory_util.h
index 190c469b5..e189b73e8 100644
--- a/test/util/memory_util.h
+++ b/test/util/memory_util.h
@@ -118,6 +118,18 @@ inline PosixErrorOr<Mapping> MmapAnon(size_t length, int prot, int flags) {
return Mmap(nullptr, length, prot, flags | MAP_ANONYMOUS, -1, 0);
}
+// Wrapper for mremap that returns a PosixErrorOr<>, since the return type of
+// void* isn't directly compatible with SyscallSucceeds.
+inline PosixErrorOr<void*> Mremap(void* old_address, size_t old_size,
+ size_t new_size, int flags,
+ void* new_address) {
+ void* rv = mremap(old_address, old_size, new_size, flags, new_address);
+ if (rv == MAP_FAILED) {
+ return PosixError(errno, "mremap failed");
+ }
+ return rv;
+}
+
// Returns true if the page containing addr is mapped.
inline bool IsMapped(uintptr_t addr) {
int const rv = msync(reinterpret_cast<void*>(addr & ~(kPageSize - 1)),
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 19:26:21 +0000