diff options
| author | Alexander Potapenko <glider@google.com> | 2026-02-10 18:41:02 +0100 |
|---|---|---|
| committer | Alexander Potapenko <glider@google.com> | 2026-02-11 07:33:38 +0000 |
| commit | 065bb22876f32a7784830f2493373c2148343a40 (patch) | |
| tree | 281343e331b911d727099d3127a7f289033569f3 /executor | |
| parent | eb08a15462c45530d2146e76f04a1a22c6541903 (diff) | |
executor: fix x86 L1 SYZOS GDT setup
Moving setup_pg_table() before setup_gdt_64() prevents the page table
initialization from accidentally erasing the newly created Global
Descriptor Table (GDT).
If the GDT is zeroed out, the CPU hardware cannot fetch the necessary
code segment descriptors to deliver interrupts or exceptions, leading
to unhandled #GP or #DF crashes.
Diffstat (limited to 'executor')
| -rw-r--r-- | executor/common_kvm_amd64.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/executor/common_kvm_amd64.h b/executor/common_kvm_amd64.h index 2c9c12a9d..cb9499a81 100644 --- a/executor/common_kvm_amd64.h +++ b/executor/common_kvm_amd64.h @@ -515,10 +515,9 @@ static void setup_gdt_ldt_pg(struct kvm_syz_vm* vm, int cpufd, int cpu_id) // RSP0 is at offset +4 bytes in a 64-bit TSS. *(volatile uint64*)(l1_tss + 4) = X86_SYZOS_ADDR_STACK0; + setup_pg_table(vm); setup_gdt_64(gdt); - syzos_setup_idt(vm, &sregs); - setup_pg_table(vm); sregs.cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG; sregs.cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR; |