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kernel: Save/restore the SSE/FPU state when executing signal handlers

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This commit is contained in:
apio 2023-07-15 11:53:50 +02:00
parent de6fe7f7c2
commit 89786d8be2
Signed by: apio
GPG Key ID: B8A7D06E42258954
2 changed files with 16 additions and 0 deletions
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10
kernel/src/arch/x86_64/CPU.h
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@ -18,6 +18,16 @@ struct FPData
void save();
void restore();
void* data()
{
return (void*)m_data;
}
usize size() const
{
return 512;
}
private:
char m_data[512] alignas(16);
bool m_already_saved;

6
kernel/src/arch/x86_64/Thread.cpp
View File

@ -111,8 +111,11 @@ bool Thread::deliver_signal(int signo, Registers* current_regs)
regs.rsp -= 128; // Skip the red zone
fp_data.save();
if (push_mem_on_stack((u8*)current_regs, sizeof(*current_regs)).has_error()) return false;
if (push_mem_on_stack((u8*)&signal_mask, sizeof(signal_mask)).has_error()) return false;
if (push_mem_on_stack((u8*)fp_data.data(), fp_data.size()).has_error()) return false;
u64 rsp = regs.rsp;
@ -150,6 +153,7 @@ void Thread::sigreturn(Registers* current_regs)
u64 rsp;
pop_mem_from_stack((u8*)&rsp, sizeof(rsp));
regs.rsp = rsp;
pop_mem_from_stack((u8*)fp_data.data(), fp_data.size());
pop_mem_from_stack((u8*)&signal_mask, sizeof(signal_mask));
pop_mem_from_stack((u8*)current_regs, sizeof(*current_regs));
memcpy(&regs, current_regs, sizeof(regs));
@ -158,6 +162,8 @@ void Thread::sigreturn(Registers* current_regs)
// FIXME: Using this, a program can craft a special RFLAGS that gives them a higher IOPL or other stuff. Find out
// exactly what bits to block from modifying.
fp_data.restore();
kinfoln("sigreturn: restored program state, sp=%p, ip=%p", (void*)regs.rsp, (void*)regs.rip);
memcpy(current_regs, &regs, sizeof(regs));