diff --git a/apps/hello.c b/apps/hello.c index cd338452..5775bd0b 100644 --- a/apps/hello.c +++ b/apps/hello.c @@ -1,24 +1,6 @@ #include -#include -#include -#include -#include -#include -int main() +int main(int argc, char** argv) { - printf("Hello world!\n"); - - mkdir("/dev", 0755); - if (mknod("/dev/console", 0666, makedev(1, 0)) < 0) - { - perror("mknod"); - return 1; - } - - const char* str = "Hello from /dev!"; - - FILE* f = fopen("/dev/console", "r+"); - if (f) fwrite(str, 1, strlen(str), f); - if (f) fclose(f); + printf("Hello world! argc=%d, argv[0]=%s, argv[1]=%s, argv[2]=%s\n", argc, argv[0], argv[1], argv[2]); } diff --git a/kernel/src/sys/exec.cpp b/kernel/src/sys/exec.cpp index fb339329..64fdea04 100644 --- a/kernel/src/sys/exec.cpp +++ b/kernel/src/sys/exec.cpp @@ -30,14 +30,26 @@ static Result> copy_string_vector_from_userspace(u64 add return result; } +static Result copy_string_vector_to_userspace(const Vector& vec, ThreadImage& image) +{ + Vector user_vec; + for (const auto& item : vec) + { + // Copy each individual string and retrieve a userspace pointer to said copy + u64 addr = TRY(image.push_mem_on_stack((const u8*)item.chars(), item.length() + 1)); + TRY(user_vec.try_append(addr)); + } + + TRY(user_vec.try_append((u64) nullptr)); + // Copy the actual vector of userspace pointers to the stack + return TRY(image.push_mem_on_stack((u8*)user_vec.data(), user_vec.size() * sizeof(u64))); +} + Result sys_exec(Registers* regs, SyscallArgs args) { auto path = TRY(MemoryManager::strdup_from_user(args[0])); auto argv = TRY(copy_string_vector_from_userspace(args[1])); - kdbgln("exec: printing out argv (argc = %zu)", argv.size()); - for (const auto& arg : argv) { kdbgln("* %s", arg.chars()); } - // FIXME: Make sure argv is not too big. auto inode = TRY(VFS::resolve_path(path.chars())); @@ -49,12 +61,21 @@ Result sys_exec(Registers* regs, SyscallArgs args) auto current = Scheduler::current(); + auto guard = make_scope_guard([current] { MMU::switch_page_directory(current->directory); }); + auto image = TRY(ThreadImage::try_load_from_elf(inode)); + kdbgln("exec: copying argv to image memory (argc = %zu)", argv.size()); + + u64 user_argv = TRY(copy_string_vector_to_userspace(argv, *image)); + usize user_argc = argv.size(); + // From now on, nothing should fail. kinfoln("exec: image load ok, will now replace existing process image"); + guard.deactivate(); + // FIXME: Close O_CLOEXEC file descriptors. // for (int i = 0; i < FD_MAX; i++) { current->fd_table[i] = {}; } @@ -64,6 +85,8 @@ Result sys_exec(Registers* regs, SyscallArgs args) MMU::switch_page_directory(current->directory); + current->set_arguments(user_argc, user_argv, 0, 0); + memcpy(regs, ¤t->regs, sizeof(*regs)); kinfoln("exec: done"); diff --git a/kernel/src/thread/ThreadImage.cpp b/kernel/src/thread/ThreadImage.cpp index 1037a47b..c8e45030 100644 --- a/kernel/src/thread/ThreadImage.cpp +++ b/kernel/src/thread/ThreadImage.cpp @@ -1,6 +1,7 @@ #include "thread/ThreadImage.h" #include "memory/MemoryManager.h" #include "thread/Thread.h" +#include static Result create_stacks(Stack& user_stack, Stack& kernel_stack) { @@ -50,10 +51,24 @@ Result> ThreadImage::try_load_from_elf(SharedPtrm_user_stack = user_stack; image->m_loaded_image_data = data; image->m_vm_allocator = move(vm_allocator); + image->m_sp = user_stack.top(); return image; } +Result ThreadImage::push_mem_on_stack(const u8* mem, usize size) +{ + if ((m_sp - size) < m_user_stack.bottom()) return err(E2BIG); + + if (!MemoryManager::validate_user_write((void*)(m_sp - size), size)) return err(EFAULT); + + m_sp -= size; + + memcpy((void*)m_sp, mem, size); + + return m_sp; +} + void ThreadImage::apply(Thread* thread) { thread->init_regs_user(); @@ -62,7 +77,7 @@ void ThreadImage::apply(Thread* thread) thread->kernel_stack = m_kernel_stack; thread->stack = m_user_stack; - thread->set_sp(m_user_stack.top()); + thread->set_sp(m_sp); thread->directory = m_directory; diff --git a/kernel/src/thread/ThreadImage.h b/kernel/src/thread/ThreadImage.h index ced6b989..4dd8d8ae 100644 --- a/kernel/src/thread/ThreadImage.h +++ b/kernel/src/thread/ThreadImage.h @@ -17,6 +17,8 @@ class ThreadImage public: static Result> try_load_from_elf(SharedPtr inode); + Result push_mem_on_stack(const u8* mem, usize size); + void apply(Thread* thread); private: @@ -25,4 +27,5 @@ class ThreadImage Stack m_user_stack; Stack m_kernel_stack; ELFData m_loaded_image_data; + u64 m_sp; }; diff --git a/libc/src/arch/x86_64/crt0.S b/libc/src/arch/x86_64/crt0.S index 35f012a0..b8e3ae98 100644 --- a/libc/src/arch/x86_64/crt0.S +++ b/libc/src/arch/x86_64/crt0.S @@ -10,11 +10,17 @@ _start: pushq %rbp # rbp=0 movq %rsp, %rbp + pushq %rsi + pushq %rdi + call libc_init # Run the global constructors. call _init + popq %rdi + popq %rsi + # Run main call main