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kernel: ensure we're saving/restoring all process state on signals

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This commit is contained in:
K. Lange 2022-03-04 22:04:11 +09:00
parent 6ff1bc5195
commit d932559d79
2 changed files with 36 additions and 9 deletions
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42
kernel/arch/aarch64/arch.c
View File

@ -70,18 +70,33 @@ static void _kill_it(uintptr_t addr, const char * action, const char * desc, siz
} while (0)
void arch_return_from_signal_handler(struct regs *r) {
uintptr_t elr;
uintptr_t spsr;
uintptr_t sp = r->user_sp;
/* Restore floating point */
POP(sp, uintptr_t, this_core->current_process->thread.context.saved[13]);
POP(sp, uintptr_t, this_core->current_process->thread.context.saved[12]);
for (int i = 0; i < 64; ++i) {
POP(sp, uint64_t, this_core->current_process->thread.fp_regs[63-i]);
}
arch_restore_floating((process_t*)this_core->current_process);
/* Interrupt system call status */
POP(sp, long, this_core->current_process->interrupted_system_call);
/* Process state */
POP(sp, uintptr_t, spsr);
this_core->current_process->thread.context.saved[11] = (spsr & 0xf0000000);
asm volatile ("msr SPSR_EL1, %0" :: "r"(this_core->current_process->thread.context.saved[11]));
POP(sp, uintptr_t, this_core->current_process->thread.context.saved[10]);
asm volatile ("msr ELR_EL1, %0" :: "r"(this_core->current_process->thread.context.saved[10]));
/* Interrupt context registers */
POP(sp, struct regs, *r);
POP(sp, uint64_t, elr);
asm volatile ("msr ELR_EL1, %0" : "=r"(elr));
dprintf("exit signal handler in SP=%#zx out SP=%#zx r=%#zx\n", sp, r->user_sp, (uintptr_t)r);
asm volatile ("msr SP_EL0, %0" :: "r"(r->user_sp));
}
/**
@ -99,20 +114,27 @@ void arch_return_from_signal_handler(struct regs *r) {
*/
void arch_enter_signal_handler(uintptr_t entrypoint, int signum, struct regs *r) {
uintptr_t elr;
uintptr_t sp = (r->user_sp - 128) & 0xFFFFFFFFFFFFFFF0;
asm volatile ("mrs %0, ELR_EL1" : "=r"(elr));
dprintf("enter signal handler old SP=%#zx new SP=%#zx r=%#zx\n", r->user_sp, sp, (uintptr_t)r);
PUSH(sp, uint64_t, elr);
/* Save essential registers */
PUSH(sp, struct regs, *r);
/* Save context that wasn't pushed above... */
asm volatile ("mrs %0, ELR_EL1" : "=r"(this_core->current_process->thread.context.saved[10]));
PUSH(sp, uintptr_t, this_core->current_process->thread.context.saved[10]);
asm volatile ("mrs %0, SPSR_EL1" : "=r"(this_core->current_process->thread.context.saved[11]));
PUSH(sp, uintptr_t, this_core->current_process->thread.context.saved[11]);
PUSH(sp, long, this_core->current_process->interrupted_system_call);
this_core->current_process->interrupted_system_call = 0;
/* Save floating point */
arch_save_floating((process_t*)this_core->current_process);
for (int i = 0; i < 64; ++i) {
PUSH(sp, uint64_t, this_core->current_process->thread.fp_regs[i]);
}
PUSH(sp, uintptr_t, this_core->current_process->thread.context.saved[12]);
PUSH(sp, uintptr_t, this_core->current_process->thread.context.saved[13]);
@ -123,13 +145,15 @@ void arch_enter_signal_handler(uintptr_t entrypoint, int signum, struct regs *r)
::
"r"(entrypoint),
"r"(sp),
"r"(this_core->current_process->thread.context.saved[11]));
"r"(0));
register uint64_t x0 __asm__("x0") = signum;
register uint64_t x30 __asm__("x30") = 0x8DEADBEEF;
register uint64_t x4 __asm__("x4") = (uintptr_t)this_core->sp_el1;
asm volatile(
"eret" :: "r"(x0), "r"(x30));
"mov sp, x4\n"
"eret\nnop\nnop" :: "r"(x0), "r"(x30), "r"(x4));
__builtin_unreachable();
}

3
kernel/arch/x86_64/user.c
View File

@ -74,6 +74,8 @@ void arch_return_from_signal_handler(struct regs *r) {
POP(r->rsp, uint64_t, this_core->current_process->thread.fp_regs[63-i]);
}
arch_restore_floating((process_t*)this_core->current_process);
POP(r->rsp, long, this_core->current_process->interrupted_system_call);
struct regs out;
@ -118,6 +120,7 @@ void arch_enter_signal_handler(uintptr_t entrypoint, int signum, struct regs *r)
PUSH(ret.rsp, long, this_core->current_process->interrupted_system_call);
this_core->current_process->interrupted_system_call = 0;
arch_save_floating((process_t*)this_core->current_process);
for (int i = 0; i < 64; ++i) {
PUSH(ret.rsp, uint64_t, this_core->current_process->thread.fp_regs[i]);
}