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Kernel: Make copy_{from,to}_user() return KResult and use TRY()

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This makes EFAULT propagation flow much more naturally. :^)
This commit is contained in:
Andreas Kling 2021-09-05 17:38:37 +02:00
parent 9903f5c6ef
commit 48a0b31c47
57 changed files with 318 additions and 551 deletions
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48
Kernel/StdLib.cpp
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@ -45,7 +45,7 @@ Kernel::KResultOr<NonnullOwnPtr<Kernel::KString>> try_copy_kstring_from_user(Use
[[nodiscard]] Optional<Time> copy_time_from_user(const timespec* ts_user)
{
timespec ts;
if (!copy_from_user(&ts, ts_user, sizeof(timespec))) {
if (copy_from_user(&ts, ts_user, sizeof(timespec)).is_error()) {
return {};
}
return Time::from_timespec(ts);
@ -53,7 +53,7 @@ Kernel::KResultOr<NonnullOwnPtr<Kernel::KString>> try_copy_kstring_from_user(Use
[[nodiscard]] Optional<Time> copy_time_from_user(const timeval* tv_user)
{
timeval tv;
if (!copy_from_user(&tv, tv_user, sizeof(timeval))) {
if (copy_from_user(&tv, tv_user, sizeof(timeval)).is_error()) {
return {};
}
return Time::from_timeval(tv);
@ -168,57 +168,55 @@ Optional<u32> user_atomic_fetch_xor_relaxed(volatile u32* var, u32 val)
return Kernel::safe_atomic_fetch_xor_relaxed(var, val);
}
extern "C" {
bool copy_to_user(void* dest_ptr, const void* src_ptr, size_t n)
KResult copy_to_user(void* dest_ptr, void const* src_ptr, size_t n)
{
bool is_user = Kernel::Memory::is_user_range(VirtualAddress(dest_ptr), n);
if (!is_user)
return false;
if (!Kernel::Memory::is_user_range(VirtualAddress(dest_ptr), n))
return EFAULT;
VERIFY(!Kernel::Memory::is_user_range(VirtualAddress(src_ptr), n));
Kernel::SmapDisabler disabler;
void* fault_at;
if (!Kernel::safe_memcpy(dest_ptr, src_ptr, n, fault_at)) {
VERIFY(VirtualAddress(fault_at) >= VirtualAddress(dest_ptr) && VirtualAddress(fault_at) <= VirtualAddress((FlatPtr)dest_ptr + n));
dbgln("copy_to_user({:p}, {:p}, {}) failed at {}", dest_ptr, src_ptr, n, VirtualAddress { fault_at });
return false;
return EFAULT;
}
return true;
return KSuccess;
}
bool copy_from_user(void* dest_ptr, const void* src_ptr, size_t n)
KResult copy_from_user(void* dest_ptr, void const* src_ptr, size_t n)
{
bool is_user = Kernel::Memory::is_user_range(VirtualAddress(src_ptr), n);
if (!is_user)
return false;
if (!Kernel::Memory::is_user_range(VirtualAddress(src_ptr), n))
return EFAULT;
VERIFY(!Kernel::Memory::is_user_range(VirtualAddress(dest_ptr), n));
Kernel::SmapDisabler disabler;
void* fault_at;
if (!Kernel::safe_memcpy(dest_ptr, src_ptr, n, fault_at)) {
VERIFY(VirtualAddress(fault_at) >= VirtualAddress(src_ptr) && VirtualAddress(fault_at) <= VirtualAddress((FlatPtr)src_ptr + n));
dbgln("copy_from_user({:p}, {:p}, {}) failed at {}", dest_ptr, src_ptr, n, VirtualAddress { fault_at });
return false;
return EFAULT;
}
return true;
return KSuccess;
}
const void* memmem(const void* haystack, size_t haystack_length, const void* needle, size_t needle_length)
{
return AK::memmem(haystack, haystack_length, needle, needle_length);
}
[[nodiscard]] bool memset_user(void* dest_ptr, int c, size_t n)
[[nodiscard]] KResult memset_user(void* dest_ptr, int c, size_t n)
{
bool is_user = Kernel::Memory::is_user_range(VirtualAddress(dest_ptr), n);
if (!is_user)
return false;
return EFAULT;
Kernel::SmapDisabler disabler;
void* fault_at;
if (!Kernel::safe_memset(dest_ptr, c, n, fault_at)) {
dbgln("memset_user({:p}, {}, {}) failed at {}", dest_ptr, c, n, VirtualAddress { fault_at });
return false;
return EFAULT;
}
return true;
return KSuccess;
}
extern "C" {
const void* memmem(const void* haystack, size_t haystack_length, const void* needle, size_t needle_length)
{
return AK::memmem(haystack, haystack_length, needle, needle_length);
}
size_t strnlen(const char* str, size_t maxlen)