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Use 0 instead of syscall_invalid in syscall jump list

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Justin C. Miller
2019-05-18 18:11:08 -07:00
parent ce035d2a43
commit a653c55941
2 changed files with 8 additions and 5 deletions
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9
src/kernel/syscall.cpp
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@@ -145,15 +145,14 @@ syscall_enable()
static constexpr unsigned num_calls = static constexpr unsigned num_calls =
static_cast<unsigned>(syscall::MAX); static_cast<unsigned>(syscall::MAX);
for (unsigned i = 0; i < num_calls; ++i) { kutil::memset(&syscall_registry, 0, sizeof(syscall_registry));
syscall_registry[i] = reinterpret_cast<uintptr_t>(syscall_invalid); kutil::memset(&syscall_names, 0, sizeof(syscall_names));
syscall_names[i] = nullptr;
}
#define SYSCALL(id, name, result, ...) \ #define SYSCALL(id, name, result, ...) \
syscall_registry[id] = reinterpret_cast<uintptr_t>(syscalls::name); \ syscall_registry[id] = reinterpret_cast<uintptr_t>(syscalls::name); \
syscall_names[id] = #name; \ syscall_names[id] = #name; \
static_assert( id <= num_calls, "Syscall " #name " has id > syscall::MAX" ); static_assert( id <= num_calls, "Syscall " #name " has id > syscall::MAX" ); \
log::debug(logs::syscall, "Enabling syscall 0x%02x as " #name , id);
#include "syscalls.inc" #include "syscalls.inc"
#undef SYSCALL #undef SYSCALL
} }

4
src/kernel/syscall.s
View File

@@ -34,12 +34,16 @@ syscall_handler_prelude:
cmp rax, MAX_SYSCALLS cmp rax, MAX_SYSCALLS
jle .ok_syscall jle .ok_syscall
.bad_syscall:
mov rdi, rax mov rdi, rax
call syscall_invalid call syscall_invalid
.ok_syscall: .ok_syscall:
lea r11, [rel syscall_registry] lea r11, [rel syscall_registry]
mov r11, [r11 + rax * 8] mov r11, [r11 + rax * 8]
cmp r11, 0
je .bad_syscall
call r11 call r11
inc qword [rel __counter_syscall_sysret] inc qword [rel __counter_syscall_sysret]