Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Many small fixes and improvements required for user tasks support #268

Merged
merged 10 commits into from
Jul 13, 2022
Merged

Many small fixes and improvements required for user tasks support #268

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
10 commits
Select commit Hold shift + click to select a range
ded8e30
arch: cleanup 32bit and add 64bit SAVE_REGS and RESTORE_REGS macros
wipawel Jul 8, 2022
f50a28f
lib: add swapgs, syscall and sysret helper functions
wipawel Jul 8, 2022
ea1fe91
arch: dump_stack() should dump at most PAGE_SIZE of stack data
wipawel Jul 8, 2022
bfb866c
arch, x86: rename MSR_SHADOW_GS_BASE to MSR_KERNEL_GS_BASE
wipawel Jul 8, 2022
62b111f
arch, segments: Add _KERN_DS64 and _USER_DS64 segment definitions
wipawel Jul 8, 2022
56915b0
arch, percpu: make percpu segment ring0 privilege only
wipawel Jul 8, 2022
b9c54aa
arch, traps: cleanup TSS segment definition and header files
wipawel Jul 8, 2022
6dc58d5
arch: add POPF() helper macro
wipawel Jul 8, 2022
2d77428
arch: add SAVE_ALL_REGS and RESTORE_ALL_REGS for 32/64 bit C code
wipawel Jul 8, 2022
72c2e67
arch: add SAVE/RESTORE macros for clobbered registers (32/64 bits)
wipawel Jul 8, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 2 additions & 2 deletions arch/x86/boot/head.S
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -63,9 +63,9 @@ GLOBAL(_start)
mov %eax, %cr3

#if defined (KTF_UNIT_TEST)
SAVE_REGS_32
SAVE_ALL_REGS32
call prot_to_real
RESTORE_REGS_32
RESTORE_ALL_REGS32
#endif

/* Enable long mode */
Expand Down
8 changes: 4 additions & 4 deletions arch/x86/entry.S
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -43,9 +43,9 @@ END_FUNC(entry_\sym)
.macro interrupt_handler sym func
ENTRY(asm_interrupt_handler_\sym)
cld
SAVE_REGS
SAVE_ALL_REGS
call \func
RESTORE_REGS
RESTORE_ALL_REGS
IRET
END_FUNC(asm_interrupt_handler_\sym)
.endm
Expand Down Expand Up @@ -75,12 +75,12 @@ exception_handler SE X86_EX_SE 1

ENTRY(handle_exception)
cld
SAVE_REGS
SAVE_ALL_REGS

mov %_ASM_SP, %_ASM_DI
call do_exception

RESTORE_REGS
RESTORE_ALL_REGS

#if defined(__x86_64__)
add $8, %_ASM_SP
Expand Down
20 changes: 9 additions & 11 deletions arch/x86/traps.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -23,20 +23,14 @@
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <apic.h>
#include <console.h>
#include <drivers/keyboard.h>
#include <drivers/pit.h>
#include <drivers/serial.h>
#include <extables.h>
#include <ktf.h>
#include <lib.h>
#include <mm/regions.h>
#include <percpu.h>
#include <processor.h>
#include <segment.h>
#include <setup.h>
#include <string.h>
#include <symbols.h>
#include <traps.h>

Expand Down Expand Up @@ -83,8 +77,9 @@ static void init_tss(percpu_t *percpu) {
percpu->tss.iopb = sizeof(percpu->tss);

/* Assign identity mapping of the tss, because GDT has only 32-bit base. */
percpu->gdt[GDT_TSS].desc = GDT_ENTRY(
DESC_FLAGS(SZ, P, CODE, A), virt_to_paddr(&percpu->tss), sizeof(percpu->tss) - 1);
percpu->gdt[GDT_TSS].desc =
GDT_ENTRY(DESC_FLAGS(GR, SZ, P, DPL0, CODE, A), virt_to_paddr(&percpu->tss),
sizeof(percpu->tss) - 1);
#if defined(__x86_64__)
percpu->gdt[GDT_TSS + 1].desc = GDT_ENTRY(0x0, 0x0, 0x0);
#endif
Expand All @@ -99,13 +94,15 @@ static void init_gdt(percpu_t *percpu) {
percpu->gdt[GDT_KERN_CS32].desc = GDT_ENTRY(DESC_FLAGS(GR, SZ, P, DPL0, S, CODE, R, A), 0x0, 0xfffff);
percpu->gdt[GDT_KERN_DS32].desc = GDT_ENTRY(DESC_FLAGS(GR, SZ, P, DPL0, S, DATA, W, A), 0x0, 0xfffff);
percpu->gdt[GDT_KERN_CS64].desc = GDT_ENTRY(DESC_FLAGS(GR, L, P, DPL0, S, CODE, R, A), 0x0, 0x00000);
percpu->gdt[GDT_KERN_DS64].desc = GDT_ENTRY(DESC_FLAGS(GR, L, P, DPL0, S, DATA, W, A), 0x0, 0x00000);

percpu->gdt[GDT_USER_CS32].desc = GDT_ENTRY(DESC_FLAGS(GR, SZ, P, DPL3, S, CODE, R, A), 0x0, 0xfffff);
percpu->gdt[GDT_USER_DS32].desc = GDT_ENTRY(DESC_FLAGS(GR, SZ, P, DPL3, S, DATA, W, A), 0x0, 0xfffff);
percpu->gdt[GDT_USER_CS64].desc = GDT_ENTRY(DESC_FLAGS(GR, L, P, DPL3, S, CODE, R, A), 0x0, 0x00000);
percpu->gdt[GDT_USER_CS64].desc = GDT_ENTRY(DESC_FLAGS(GR, L, P, DPL3, S, CODE, R, A), 0x0, 0xfffff);
percpu->gdt[GDT_USER_DS64].desc = GDT_ENTRY(DESC_FLAGS(GR, L, P, DPL3, S, DATA, W, A), 0x0, 0xfffff);

/* Assign identity mapping of the percpu, because GDT has only 32-bit base. */
percpu->gdt[GDT_PERCPU].desc = GDT_ENTRY(DESC_FLAGS(GR, L, P, DPL3, S, CODE, R, A), virt_to_paddr(percpu), PAGE_SIZE);
percpu->gdt[GDT_PERCPU].desc = GDT_ENTRY(DESC_FLAGS(GR, L, P, DPL0, S, CODE, R, A), virt_to_paddr(percpu), PAGE_SIZE);
/* clang-format on */

percpu->gdt_ptr.size = sizeof(percpu->gdt) - 1;
Expand All @@ -115,6 +112,7 @@ static void init_gdt(percpu_t *percpu) {
lgdt(&percpu->gdt_ptr);

write_gs(GDT_PERCPU << 3);
wrmsr(MSR_KERNEL_GS_BASE, 0x0);

init_tss(percpu);
}
Expand Down Expand Up @@ -220,7 +218,7 @@ static void dump_stack(const struct cpu_regs *regs, unsigned words) {
unsigned lines = DUMP_STACK_LINES;

printk("STACK[%p]:", sp);
for (unsigned i = 0; i == 0 || (_ul(&sp[i]) % PAGE_SIZE_2M); i++) {
for (unsigned i = 0; i == 0 || (_ul(&sp[i]) % PAGE_SIZE); i++) {
if ((i % words) == 0) {
if (lines-- == 0)
break;
Expand Down
150 changes: 123 additions & 27 deletions include/arch/x86/asm-macros.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -68,34 +68,28 @@
rep outsb
.endm

.macro SAVE_REGS_32
push %eax
push %ebx
push %ecx
push %edx
push %esi
push %edi
push %ebp
.endm

.macro RESTORE_REGS_32
pop %ebp
pop %edi
pop %esi
pop %edx
pop %ecx
pop %ebx
pop %eax
.endm

.macro SAVE_REGS
.macro SAVE_ALL_REGS32
push %_ASM_AX
push %_ASM_BX
push %_ASM_CX
push %_ASM_DX
push %_ASM_SI
push %_ASM_DI
push %_ASM_BP
.endm

.macro RESTORE_ALL_REGS32
pop %_ASM_BP
pop %_ASM_DI
pop %_ASM_SI
pop %_ASM_DX
pop %_ASM_CX
pop %_ASM_BX
pop %_ASM_AX
.endm

.macro SAVE_ALL_REGS
SAVE_ALL_REGS32
#if defined(__x86_64__)
push %r8
push %r9
Expand All @@ -108,7 +102,7 @@
#endif
.endm

.macro RESTORE_REGS
.macro RESTORE_ALL_REGS
#if defined(__x86_64__)
pop %r15
pop %r14
Expand All @@ -118,14 +112,30 @@
pop %r10
pop %r9
pop %r8
#endif
RESTORE_ALL_REGS32
.endm

.macro SAVE_CALLEE_SAVED_REGS
push %_ASM_BX
push %_ASM_BP
#if defined(__x86_64__)
push %r12
push %r13
push %r14
push %r15
#endif
.endm

.macro RESTORE_CALLEE_SAVED_REGS
#if defined(__x86_64__)
pop %r15
pop %r14
pop %r13
pop %r12
#endif
pop %_ASM_BP
pop %_ASM_DI
pop %_ASM_SI
pop %_ASM_DX
pop %_ASM_CX
pop %_ASM_BX
pop %_ASM_AX
.endm

.macro PUSHF
Expand Down Expand Up @@ -194,6 +204,92 @@ name ## _end:
4:.align 4;
/* clang-format on */

#else

/* clang-format off */
#if defined(__x86_64__)
#define SAVE_ALL_REGS64() \
"push %%r8\n" \
"push %%r9\n" \
"push %%r10\n" \
"push %%r11\n" \
"push %%r12\n" \
"push %%r13\n" \
"push %%r14\n" \
"push %%r15\n"

#define RESTORE_ALL_REGS64() \
"pop %%" STR(r15) "\n" \
"pop %%" STR(r14) "\n" \
"pop %%" STR(r13) "\n" \
"pop %%" STR(r12) "\n" \
"pop %%" STR(r11) "\n" \
"pop %%" STR(r10) "\n" \
"pop %%" STR(r9) "\n" \
"pop %%" STR(r8) "\n"
#else
#define SAVE_ALL_REGS64()
#define RESTORE_ALL_REGS64()
#endif

#define SAVE_ALL_REGS() \
"push %%" STR(_ASM_AX) "\n" \
"push %%" STR(_ASM_BX) "\n" \
"push %%" STR(_ASM_CX) "\n" \
"push %%" STR(_ASM_DX) "\n" \
"push %%" STR(_ASM_SI) "\n" \
"push %%" STR(_ASM_DI) "\n" \
"push %%" STR(_ASM_BP) "\n" \
SAVE_ALL_REGS64()

#define RESTORE_ALL_REGS() \
RESTORE_ALL_REGS64() \
"pop %%" STR(_ASM_BP) "\n" \
"pop %%" STR(_ASM_DI) "\n" \
"pop %%" STR(_ASM_SI) "\n" \
"pop %%" STR(_ASM_DX) "\n" \
"pop %%" STR(_ASM_CX) "\n" \
"pop %%" STR(_ASM_BX) "\n" \
"pop %%" STR(_ASM_AX) "\n"

#if defined(__x86_64__)
#define SAVE_CLOBBERED_REGS64() \
"push %%r8\n" \
"push %%r9\n" \
"push %%r10\n" \
"push %%r11\n" \

#define RESTORE_CLOBBERED_REGS64() \
"pop %%" STR(r11) "\n" \
"pop %%" STR(r10) "\n" \
"pop %%" STR(r9) "\n" \
"pop %%" STR(r8) "\n"
#else
#define SAVE_CLOBBERED_REGS64()
#define RESTORE_CLOBBERED_REGS64()
#endif

#define SAVE_CLOBBERED_REGS() \
"push %%" STR(_ASM_CX) "\n" \
"push %%" STR(_ASM_DX) "\n" \
"push %%" STR(_ASM_SI) "\n" \
"push %%" STR(_ASM_DI) "\n" \
SAVE_CLOBBERED_REGS64()

#define RESTORE_CLOBBERED_REGS() \
RESTORE_CLOBBERED_REGS64() \
"pop %%" STR(_ASM_DI) "\n" \
"pop %%" STR(_ASM_SI) "\n" \
"pop %%" STR(_ASM_DX) "\n" \
"pop %%" STR(_ASM_CX) "\n" \
/* clang-format on */

#if defined(__x86_64__)
#define POPF() "popfq\n"
#else
#define POPF() "popf\n"
#endif

#endif

#endif /* KTF_ASM_MACROS_H */
3 changes: 2 additions & 1 deletion include/arch/x86/processor.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,7 @@
#ifndef KTF_PROCESSOR_H
#define KTF_PROCESSOR_H

#include <asm-macros.h>
#include <compiler.h>

/*
Expand Down Expand Up @@ -130,7 +131,7 @@

#define MSR_FS_BASE 0xc0000100
#define MSR_GS_BASE 0xc0000101
#define MSR_SHADOW_GS_BASE 0xc0000102
#define MSR_KERNEL_GS_BASE 0xc0000102

#define MSR_TSC_AUX 0xc0000103

Expand Down
37 changes: 20 additions & 17 deletions include/arch/x86/segment.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,40 +33,43 @@
#define GDT_KERN_CS32 0x1
#define GDT_KERN_DS32 0x2
#define GDT_KERN_CS64 0x3
#define GDT_KERN_DS64 0x4

#define GDT_RMODE_CS16 0x4
#define GDT_RMODE_DS16 0x5
#define GDT_RMODE_CS16 0x5
#define GDT_RMODE_DS16 0x6

#define GDT_BOOT_TSS 0x4
#define GDT_BOOT_TSS_DF 0x5
#define GDT_BOOT_TSS 0x5
#define GDT_BOOT_TSS_DF 0x6

#define GDT_USER_CS32 0x4
#define GDT_USER_DS32 0x5
#define GDT_USER_CS64 0x6
#define GDT_USER_CS32 0x5
#define GDT_USER_DS32 0x6
#define GDT_USER_CS64 0x7
#define GDT_USER_DS64 0x8

#define GDT_TSS 0x7
#define GDT_TSS_DF 0x8
#define GDT_TSS 0x9
#define GDT_TSS_DF 0xa

#define GDT_RMODE_TSS 0x6
#define GDT_RMODE_TSS_DF 0x7
#define GDT_RMODE_TSS 0x7
#define GDT_RMODE_TSS_DF 0x8

#define GDT_PERCPU 0x9
#define GDT_PERCPU 0xb

#define NR_BOOT_GDT_ENTRIES 6
#define NR_RMODE_GDT_ENTRIES 8
#define NR_GDT_ENTRIES 10
#define NR_BOOT_GDT_ENTRIES 7
#define NR_RMODE_GDT_ENTRIES 9
#define NR_GDT_ENTRIES 12

#define __KERN_CS32 (GDT_KERN_CS32 << 3)
#define __KERN_DS32 (GDT_KERN_DS32 << 3)
#define __KERN_CS64 (GDT_KERN_CS64 << 3)
#define __KERN_DS64 (GDT_KERN_DS64 << 3)

#define __KERN_CS16 (GDT_RMODE_CS16 << 3)
#define __KERN_DS16 (GDT_RMODE_DS16 << 3)

#define __USER_CS32 ((GDT_USER_CS32 << 3) | 3)
#define __USER_DS32 ((GDT_USER_DS32 << 3) | 3)
#define __USER_CS64 ((GDT_USER_CS64 << 3) | 3)
#define __USER_DS64 ((GDT_USER_DS32 << 3) | 3)
#define __USER_DS64 ((GDT_USER_DS64 << 3) | 3)

#if defined(__i386__)
#define __KERN_CS __KERN_CS32
Expand All @@ -76,7 +79,7 @@
#define __USER_DS __USER_DS32
#else
#define __KERN_CS __KERN_CS64
#define __KERN_DS (0)
#define __KERN_DS __KERN_DS64

#define __USER_CS __USER_CS64
#define __USER_DS __USER_DS64
Expand Down
12 changes: 12 additions & 0 deletions include/lib.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -308,6 +308,18 @@ static inline void flush_tlb(void) { write_cr3(read_cr3()); }

static inline void ud2(void) { asm volatile("ud2"); }

static inline void swapgs(void) { asm volatile("swapgs"); }

static inline void syscall(void) { asm volatile("syscall"); }

static inline void sysret(void) {
#if defined(__i386__)
asm volatile("sysret");
#else
asm volatile("sysretq");
#endif
}

#define BUG() \
do { \
panic("BUG in %s() at line %u\n", __func__, __LINE__); \
Expand Down