serenity/Kernel/Syscalls/umask.cpp

/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <Kernel/Process.h>

namespace Kernel {

ErrorOr<FlatPtr> Process::sys$umask(mode_t mask)
{
    VERIFY_NO_PROCESS_BIG_LOCK(this);
    TRY(require_promise(Pledge::stdio));
    return with_mutable_protected_data([&](auto& protected_data) -> ErrorOr<FlatPtr> {
        auto old_mask = protected_data.umask;
        protected_data.umask = mask & 0777;
        return old_mask;
    });
}

}
Kernel: Move syscall implementations out of Process.cpp This is something I've been meaning to do for a long time, and here we finally go. This patch moves all sys$foo functions out of Process.cpp and into files in Kernel/Syscalls/. It's not exactly one syscall per file (although it could be, but I got a bit tired of the repetitive work here..) This makes hacking on individual syscalls a lot less painful since you don't have to rebuild nearly as much code every time. I'm also hopeful that this makes it easier to understand individual syscalls. :^) 2020-07-30 23:38:15 +02:00			`/*`
			`* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>`
			`*`
Everything: Move to SPDX license identifiers in all files. SPDX License Identifiers are a more compact / standardized way of representing file license information. See: https://spdx.dev/resources/use/#identifiers This was done with the `ambr` search and replace tool. ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt * 2021-04-22 01:24:48 -07:00			`* SPDX-License-Identifier: BSD-2-Clause`
Kernel: Move syscall implementations out of Process.cpp This is something I've been meaning to do for a long time, and here we finally go. This patch moves all sys$foo functions out of Process.cpp and into files in Kernel/Syscalls/. It's not exactly one syscall per file (although it could be, but I got a bit tired of the repetitive work here..) This makes hacking on individual syscalls a lot less painful since you don't have to rebuild nearly as much code every time. I'm also hopeful that this makes it easier to understand individual syscalls. :^) 2020-07-30 23:38:15 +02:00			`*/`

			`#include <Kernel/Process.h>`

			`namespace Kernel {`

Kernel: Replace KResult and KResultOr<T> with Error and ErrorOr<T> We now use AK::Error and AK::ErrorOr<T> in both kernel and userspace! This was a slightly tedious refactoring that took a long time, so it's not unlikely that some bugs crept in. Nevertheless, it does pass basic functionality testing, and it's just real nice to finally see the same pattern in all contexts. :^) 2021-11-08 00:51:39 +01:00			`ErrorOr<FlatPtr> Process::sys$umask(mode_t mask)`
Kernel: Move syscall implementations out of Process.cpp This is something I've been meaning to do for a long time, and here we finally go. This patch moves all sys$foo functions out of Process.cpp and into files in Kernel/Syscalls/. It's not exactly one syscall per file (although it could be, but I got a bit tired of the repetitive work here..) This makes hacking on individual syscalls a lot less painful since you don't have to rebuild nearly as much code every time. I'm also hopeful that this makes it easier to understand individual syscalls. :^) 2020-07-30 23:38:15 +02:00			`{`
Kernel: Mark sys$umask as not needing the big lock The body of this syscall is already serialized by calling with_mutable_protected_data(). 2023-04-03 16:37:34 +02:00			`VERIFY_NO_PROCESS_BIG_LOCK(this);`
Kernel: Handle promise violations in the syscall handler Previously we would crash the process immediately when a promise violation was found during a syscall. This is error prone, as we don't unwind the stack. This means that in certain cases we can leak resources, like an OwnPtr / RefPtr tracked on the stack. Or even leak a lock acquired in a ScopeLockLocker. To remedy this situation we move the promise violation handling to the syscall handler, right before we return to user space. This allows the code to follow the normal unwind path, and grantees there is no longer any cleanup that needs to occur. The Process::require_promise() and Process::require_no_promises() functions were modified to return ErrorOr<void> so we enforce that the errors are always propagated by the caller. 2021-12-29 01:11:45 -08:00			`TRY(require_promise(Pledge::stdio));`
Kernel: Guard Process "protected data" with a spinlock This ensures that both mutable and immutable access to the protected data of a process is serialized. Note that there may still be multiple TOCTOU issues around this, as we have a bunch of convenience accessors that make it easy to introduce them. We'll need to audit those as well. 2022-08-21 12:18:26 +02:00			`return with_mutable_protected_data([&](auto& protected_data) -> ErrorOr<FlatPtr> {`
			`auto old_mask = protected_data.umask;`
			`protected_data.umask = mask & 0777;`
			`return old_mask;`
			`});`
Kernel: Move syscall implementations out of Process.cpp This is something I've been meaning to do for a long time, and here we finally go. This patch moves all sys$foo functions out of Process.cpp and into files in Kernel/Syscalls/. It's not exactly one syscall per file (although it could be, but I got a bit tired of the repetitive work here..) This makes hacking on individual syscalls a lot less painful since you don't have to rebuild nearly as much code every time. I'm also hopeful that this makes it easier to understand individual syscalls. :^) 2020-07-30 23:38:15 +02:00			`}`

			`}`