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path: root/Kernel/Syscalls/chdir.cpp
AgeCommit message (Collapse)Author
2021-03-01Kernel: Make all syscall functions return KResultOr<T>Andreas Kling
This makes it a lot easier to return errors since we no longer have to worry about negating EFOO errors and can just return them flat.
2021-01-16Kernel+LibC: Make sys$getcwd truncate the result silentlyBen Wiederhake
This gives us the superpower of knowing the ideal buffer length if it fails. See also https://github.com/SerenityOS/serenity/discussions/4357
2020-09-13Kernel: Make copy_to/from_user safe and remove unnecessary checksTom
Since the CPU already does almost all necessary validation steps for us, we don't really need to attempt to do this. Doing it ourselves doesn't really work very reliably, because we'd have to account for other processors modifying virtual memory, and we'd have to account for e.g. pages not being able to be allocated due to insufficient resources. So change the copy_to/from_user (and associated helper functions) to use the new safe_memcpy, which will return whether it succeeded or not. The only manual validation step needed (which the CPU can't perform for us) is making sure the pointers provided by user mode aren't pointing to kernel mappings. To make it easier to read/write from/to either kernel or user mode data add the UserOrKernelBuffer helper class, which will internally either use copy_from/to_user or directly memcpy, or pass the data through directly using a temporary buffer on the stack. Last but not least we need to keep syscall params trivial as we need to copy them from/to user mode using copy_from/to_user.
2020-07-31Kernel: Use Userspace<T> in sys$getcwd() and sys$chdir()Andreas Kling
Add more validation helper overloads as we go. :^)
2020-07-30Kernel: Move syscall implementations out of Process.cppAndreas Kling
This is something I've been meaning to do for a long time, and here we finally go. This patch moves all sys$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. :^)