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Kernel: Cleanup accessing userspace memory

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Instead of doing page validiation and loading manually we just do simple
memcpy and handle the possible page faults
This commit is contained in:
Bananymous
2026-04-02 16:36:33 +03:00
parent 9589b5984d
commit f77aa65dc5
5 changed files with 207 additions and 220 deletions
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36
kernel/kernel/IDT.cpp
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@@ -164,6 +164,33 @@ namespace Kernel
"Unkown Exception 0x1F",
};
extern "C" uint8_t safe_user_memcpy[];
extern "C" uint8_t safe_user_memcpy_end[];
extern "C" uint8_t safe_user_memcpy_fault[];
extern "C" uint8_t safe_user_strncpy[];
extern "C" uint8_t safe_user_strncpy_end[];
extern "C" uint8_t safe_user_strncpy_fault[];
struct safe_user_page_fault
{
const uint8_t* ip_start;
const uint8_t* ip_end;
const uint8_t* ip_fault;
};
static constexpr safe_user_page_fault s_safe_user_page_faults[] {
{
.ip_start = safe_user_memcpy,
.ip_end = safe_user_memcpy_end,
.ip_fault = safe_user_memcpy_fault,
},
{
.ip_start = safe_user_strncpy,
.ip_end = safe_user_strncpy_end,
.ip_fault = safe_user_strncpy_fault,
},
};
extern "C" void cpp_isr_handler(uint32_t isr, uint32_t error, InterruptStack* interrupt_stack, const Registers* regs)
{
if (g_paniced)
@@ -201,6 +228,15 @@ namespace Kernel
if (result.value())
return;
const uint8_t* ip = reinterpret_cast<const uint8_t*>(interrupt_stack->ip);
for (const auto& safe_user : s_safe_user_page_faults)
{
if (ip < safe_user.ip_start || ip >= safe_user.ip_end)
continue;
interrupt_stack->ip = reinterpret_cast<vaddr_t>(safe_user.ip_fault);
return;
}
break;
}
case ISR::DeviceNotAvailable: