diff options
| author | Ian Moffett <ian@osmora.org> | 2025-07-17 00:24:02 -0400 |
|---|---|---|
| committer | Ian Moffett <ian@osmora.org> | 2025-07-17 00:31:19 -0400 |
| commit | 24b850e55e1dd8c36a4b2e946b941422db17abb5 (patch) | |
| tree | c3f48f84a9e8ff5b2f1fab680118ffe70dda1075 /sys/arch/amd64 | |
| parent | a802482670de836e7b255805f6d05cd908992a34 (diff) | |
kernel/amd64: Set up seperate syscall stack
It is a good idea to have a completely different stack during syscalls.
This commit implements a TSS IST entry for syscalls.
Signed-off-by: Ian Moffett <ian@osmora.org>
Diffstat (limited to 'sys/arch/amd64')
| -rw-r--r-- | sys/arch/amd64/amd64/machdep.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c index 40950f9..efd1af8 100644 --- a/sys/arch/amd64/amd64/machdep.c +++ b/sys/arch/amd64/amd64/machdep.c @@ -111,8 +111,16 @@ tlb_shootdown_isr(void *p) } static void -setup_vectors(void) +setup_vectors(struct cpu_info *ci) { + union tss_stack scstack; + + /* Try to allocate a syscall stack */ + if (tss_alloc_stack(&scstack, DEFAULT_PAGESIZE) != 0) { + panic("failed to allocate syscall stack\n"); + } + + tss_update_ist(ci, scstack, IST_SYSCALL); idt_set_desc(0x0, IDT_TRAP_GATE, ISR(arith_err), 0); idt_set_desc(0x2, IDT_TRAP_GATE, ISR(nmi), 0); idt_set_desc(0x3, IDT_TRAP_GATE, ISR(breakpoint_handler), 0); @@ -125,7 +133,7 @@ setup_vectors(void) idt_set_desc(0xC, IDT_TRAP_GATE, ISR(ss_fault), 0); idt_set_desc(0xD, IDT_TRAP_GATE, ISR(general_prot), 0); idt_set_desc(0xE, IDT_TRAP_GATE, ISR(page_fault), 0); - idt_set_desc(0x80, IDT_USER_INT_GATE, ISR(syscall_isr), 0); + idt_set_desc(0x80, IDT_USER_INT_GATE, ISR(syscall_isr), IST_SYSCALL); idt_set_desc(HALT_VECTOR, IDT_INT_GATE, ISR(cpu_halt_isr), 0); idt_set_desc(TLB_VECTOR, IDT_INT_GATE, ISR(tlb_shootdown_isr), 0); pin_isr_load(); @@ -405,10 +413,10 @@ cpu_startup(struct cpu_info *ci) gdt_load(); idt_load(); - setup_vectors(); wrmsr(IA32_GS_BASE, (uintptr_t)ci); - init_tss(ci); + setup_vectors(ci); + try_mitigate_spectre(); cpu_get_info(ci); |