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Kernel: Move all CPU feature initialization into cpu_setup()

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..and do it very very early in boot.
This commit is contained in:
Andreas Kling 2020-01-18 10:11:29 +01:00
parent 210adaeca6
commit 6fea316611
4 changed files with 61 additions and 90 deletions
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109
Kernel/Arch/i386/CPU.cpp
View file

@ -578,7 +578,7 @@ bool g_cpu_supports_sse;
bool g_cpu_supports_tsc;
bool g_cpu_supports_umip;
void detect_cpu_features()
void cpu_detect()
{
CPUID processor_info(0x1);
g_cpu_supports_pae = (processor_info.edx() & (1 << 6));
@ -612,17 +612,22 @@ void clac()
: "cc");
}
void x86_enable_pae()
void cpu_setup()
{
// Turn on CR4.PAE
asm volatile(
"mov %cr4, %eax\n"
"orl $0x20, %eax\n"
"mov %eax, %cr4\n");
}
cpu_detect();
if (g_cpu_supports_sse) {
sse_init();
kprintf("x86: SSE support enabled\n");
}
asm volatile(
"movl %%cr0, %%eax\n"
"orl $0x00010000, %%eax\n"
"movl %%eax, %%cr0\n" ::
: "%eax", "memory");
kprintf("x86: WP support enabled\n");
void x86_enable_pge()
{
if (g_cpu_supports_pge) {
// Turn on CR4.PGE so the CPU will respect the G bit in page tables.
asm volatile(
@ -633,39 +638,7 @@ void x86_enable_pge()
} else {
kprintf("x86: PGE support not detected\n");
}
}
void x86_enable_smep()
{
if (g_cpu_supports_smep) {
// Turn on CR4.SMEP
asm volatile(
"mov %cr4, %eax\n"
"orl $0x100000, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: SMEP support enabled\n");
} else {
kprintf("x86: SMEP support not detected\n");
}
}
void x86_enable_smap()
{
if (g_cpu_supports_smap) {
// Turn on CR4.SMAP
kprintf("x86: Enabling SMAP\n");
asm volatile(
"mov %cr4, %eax\n"
"orl $0x200000, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: SMAP support enabled\n");
} else {
kprintf("x86: SMAP support not detected\n");
}
}
void x86_enable_nx()
{
if (g_cpu_supports_nx) {
// Turn on IA32_EFER.NXE
asm volatile(
@ -677,13 +650,49 @@ void x86_enable_nx()
} else {
kprintf("x86: NX support not detected\n");
}
}
void x86_enable_wp()
{
asm volatile(
"movl %%cr0, %%eax\n"
"orl $0x00010000, %%eax\n"
"movl %%eax, %%cr0\n" ::
: "%eax", "memory");
if (g_cpu_supports_smep) {
// Turn on CR4.SMEP
asm volatile(
"mov %cr4, %eax\n"
"orl $0x100000, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: SMEP support enabled\n");
} else {
kprintf("x86: SMEP support not detected\n");
}
if (g_cpu_supports_smap) {
// Turn on CR4.SMAP
kprintf("x86: Enabling SMAP\n");
asm volatile(
"mov %cr4, %eax\n"
"orl $0x200000, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: SMAP support enabled\n");
} else {
kprintf("x86: SMAP support not detected\n");
}
if (g_cpu_supports_umip) {
asm volatile(
"mov %cr4, %eax\n"
"orl $0x800, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: UMIP support enabled\n");
}
if (g_cpu_supports_tsc) {
asm volatile(
"mov %cr4, %eax\n"
"orl $0x4, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: RDTSC support restricted\n");
}
if (g_cpu_supports_rdrand) {
kprintf("x86: Using RDRAND for good randomness\n");
} else {
kprintf("x86: No RDRAND support detected. Randomness will be shitty\n");
}
}

8
Kernel/Arch/i386/CPU.h
View file

@ -553,7 +553,7 @@ public:
}
};
void detect_cpu_features();
void cpu_setup();
extern bool g_cpu_supports_nx;
extern bool g_cpu_supports_pae;
extern bool g_cpu_supports_pge;
@ -566,12 +566,6 @@ extern bool g_cpu_supports_umip;
void stac();
void clac();
void x86_enable_pae();
void x86_enable_pge();
void x86_enable_smep();
void x86_enable_smap();
void x86_enable_nx();
void x86_enable_wp();
class SmapDisabler {
public:

7
Kernel/VM/MemoryManager.cpp
View file

@ -53,13 +53,6 @@ MemoryManager::MemoryManager()
parse_memory_map();
x86_enable_pae();
x86_enable_pge();
x86_enable_smep();
x86_enable_smap();
x86_enable_nx();
x86_enable_wp();
asm volatile("movl %%eax, %%cr3" ::"a"(kernel_page_directory().cr3()));
setup_low_1mb();

27
Kernel/init.cpp
View file

@ -277,7 +277,7 @@ extern "C" [[noreturn]] void init()
if (cmdline && bad_prefix_check(reinterpret_cast<const char*>(cmdline), "serial_debug"))
set_serial_debug(true);
detect_cpu_features();
cpu_setup();
kmalloc_init();
slab_alloc_init();
@ -309,32 +309,7 @@ extern "C" [[noreturn]] void init()
kprintf("Starting SerenityOS...\n");
if (g_cpu_supports_sse) {
sse_init();
kprintf("x86: SSE support enabled\n");
}
if (g_cpu_supports_umip) {
asm volatile(
"mov %cr4, %eax\n"
"orl $0x800, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: UMIP support enabled\n");
}
if (g_cpu_supports_tsc) {
asm volatile(
"mov %cr4, %eax\n"
"orl $0x4, %eax\n"
"mov %eax, %cr4\n");
kprintf("x86: RDTSC support restricted\n");
}
if (g_cpu_supports_rdrand) {
kprintf("x86: Using RDRAND for good randomness\n");
} else {
kprintf("x86: No RDRAND support detected. Randomness will be shitty\n");
}
__stack_chk_guard = get_good_random<u32>();