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Utilities+Tests: Convert test_efault to be LibTest based

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This test exposed a kernel panic in is_user_range calculations, so let's
convert it to be a LibTest test so we can prevent regressions in mmap,
the page allocator, and the memory manager.
This commit is contained in:
Andrew Kaster 2021-07-06 20:21:14 -06:00 • committed by Andreas Kling
parent 578d45b480
commit 4cc75501d7
1 changed files with 23 additions and 9 deletions
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32
Userland/Utilities/test_efault.cpp → Tests/Kernel/TestEFault.cpp
View file

@ -1,5 +1,6 @@
/* /*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org> * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021, Andrew Kaster <akaster@serenityos.org>
* *
* SPDX-License-Identifier: BSD-2-Clause * SPDX-License-Identifier: BSD-2-Clause
*/ */
@ -7,6 +8,7 @@
#include <AK/Assertions.h> #include <AK/Assertions.h>
#include <AK/Format.h> #include <AK/Format.h>
#include <AK/Types.h> #include <AK/Types.h>
#include <LibTest/TestCase.h>
#include <errno.h> #include <errno.h>
#include <fcntl.h> #include <fcntl.h>
#include <stdio.h> #include <stdio.h>
@ -16,6 +18,7 @@
#define EXPECT_OK(syscall, address, size) \ #define EXPECT_OK(syscall, address, size) \
do { \ do { \
rc = syscall(fd, (void*)(address), (size_t)(size)); \ rc = syscall(fd, (void*)(address), (size_t)(size)); \
EXPECT(rc >= 0); \
if (rc < 0) { \ if (rc < 0) { \
warnln("Expected success: " #syscall "({:p}, {}), got rc={}, errno={}", (void*)(address), (size_t)(size), rc, errno); \ warnln("Expected success: " #syscall "({:p}, {}), got rc={}, errno={}", (void*)(address), (size_t)(size), rc, errno); \
} \ } \
@ -24,6 +27,8 @@
#define EXPECT_EFAULT(syscall, address, size) \ #define EXPECT_EFAULT(syscall, address, size) \
do { \ do { \
rc = syscall(fd, (void*)(address), (size_t)(size)); \ rc = syscall(fd, (void*)(address), (size_t)(size)); \
EXPECT(rc < 0); \
EXPECT_EQ(errno, EFAULT); \
if (rc >= 0 || errno != EFAULT) { \ if (rc >= 0 || errno != EFAULT) { \
warnln("Expected EFAULT: " #syscall "({:p}, {}), got rc={}, errno={}", (void*)(address), (size_t)(size), rc, errno); \ warnln("Expected EFAULT: " #syscall "({:p}, {}), got rc={}, errno={}", (void*)(address), (size_t)(size), rc, errno); \
} \ } \
@ -32,15 +37,17 @@
#define EXPECT_EFAULT_NO_FD(syscall, address, size) \ #define EXPECT_EFAULT_NO_FD(syscall, address, size) \
do { \ do { \
rc = syscall((address), (size_t)(size)); \ rc = syscall((address), (size_t)(size)); \
EXPECT(rc < 0); \
EXPECT_EQ(errno, EFAULT); \
if (rc >= 0 || errno != EFAULT) { \ if (rc >= 0 || errno != EFAULT) { \
warnln("Expected EFAULT: " #syscall "({:p}, {}), got rc={}, errno={}", (void*)(address), (size_t)(size), rc, errno); \ warnln("Expected EFAULT: " #syscall "({:p}, {}), got rc={}, errno={}", (void*)(address), (size_t)(size), rc, errno); \
} \ } \
} while (0) } while (0)
int main(int, char**) TEST_CASE(test_efault)
{ {
int fd = open("/dev/zero", O_RDONLY); int fd = open("/dev/zero", O_RDONLY);
int rc; int rc = -1;
// Test a one-page mapping (4KB) // Test a one-page mapping (4KB)
u8* one_page = (u8*)mmap(nullptr, 4096, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); u8* one_page = (u8*)mmap(nullptr, 4096, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
@ -66,19 +73,26 @@ int main(int, char**)
EXPECT_EFAULT(read, one_page, (u32)distance + 1024); EXPECT_EFAULT(read, one_page, (u32)distance + 1024);
// Test every kernel page just because. // Test every kernel page just because.
for (u64 kernel_address = 0xc0000000; kernel_address <= 0xffffffff; kernel_address += PAGE_SIZE) { constexpr auto user_range_ceiling = 0xbe000000u;
EXPECT_EFAULT(read, (void*)kernel_address, 1); u8* jerk_page = nullptr;
for (u64 kernel_address = user_range_ceiling; kernel_address <= 0xffffffff; kernel_address += PAGE_SIZE) {
jerk_page = (u8*)mmap((void*)kernel_address, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, 0, 0);
EXPECT_EQ(jerk_page, MAP_FAILED);
EXPECT_EQ(errno, EFAULT);
} }
// Test the page just below where the kernel VM begins. // Test the page just below where the user VM ends.
u8* jerk_page = (u8*)mmap((void*)(0xc0000000 - PAGE_SIZE), PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, 0, 0); jerk_page = (u8*)mmap((void*)(user_range_ceiling - PAGE_SIZE), PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, 0, 0);
VERIFY(jerk_page == (void*)(0xc0000000 - PAGE_SIZE)); EXPECT_EQ(jerk_page, MAP_FAILED);
EXPECT_EQ(errno, EFAULT);
// Test the page just before that
jerk_page = (u8*)mmap((void*)(user_range_ceiling - (2 * PAGE_SIZE)), PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
EXPECT_EQ(jerk_page, (u8*)(user_range_ceiling - (2 * PAGE_SIZE)));
EXPECT_OK(read, jerk_page, 4096); EXPECT_OK(read, jerk_page, 4096);
EXPECT_EFAULT(read, jerk_page, 4097); EXPECT_EFAULT(read, jerk_page, 4097);
// Test something that would wrap around the 2^32 mark. // Test something that would wrap around the 2^32 mark.
EXPECT_EFAULT(read, jerk_page, 0x50000000); EXPECT_EFAULT(read, jerk_page, 0x50000000);
return 0;
} }