pm24.git/arch/x86/um/shared, branch master

um: switch to regset API and depend on XSTATE

2024-10-23T10:13:16Z

The PTRACE_GETREGSET API has now existed since Linux 2.6.33. The XSAVE CPU feature should also be sufficiently common to be able to rely on it. With this, define our internal FP state to be the hosts XSAVE data. Add discovery for the hosts XSAVE size and place the FP registers at the end of task_struct so that we can adjust the size at runtime. Next we can implement the regset API on top and update the signal handling as well as ptrace APIs to use them. Also switch coredump creation to use the regset API and finally set HAVE_ARCH_TRACEHOOK. This considerably improves the signal frames. Previously they might not have contained all the registers (i386) and also did not have the sizes and magic values set to the correct values to permit userspace to decode the frame. As a side effect, this will permit UML to run on hosts with newer CPU extensions (such as AMX) that need even more register state. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20241023094120.4083426-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg

um: make stub_exe _start() pure inline asm

2024-10-23T07:04:59Z

Since __attribute__((naked)) cannot be used with functions containing C statements, just generate the few instructions it needs in assembly directly. While at it, fix the stack usage ("1 + 2*x - 1" is odd) and document what it must do, and why it must adjust the stack. Fixes: 8508a5e0e9db ("um: Fix misaligned stack in stub_exe") Link: https://lore.kernel.org/linux-um/CABVgOSntH-uoOFMP5HwMXjx_f1osMnVdhgKRKm4uz6DFm2Lb8Q@mail.gmail.com/ Reviewed-by: David Gow Signed-off-by: Johannes Berg

um: Calculate stub data address relative to stub code

2024-10-10T11:37:22Z

Instead of using the current stack pointer, we can also use the current instruction to calculate where the stub data is. With this the stub data only needs to be aligned to a full page boundary. Changing this has the advantage that we do not have a hole in the memory space above the stub data (which would need to be explicitly cleared). Another motivation to do this is that with the planned addition of a SECCOMP based userspace the stack pointer may not be fully trustworthy. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240919124511.282088-7-benjamin@sipsolutions.net Signed-off-by: Johannes Berg

um: Add generic stub_syscall1 function

2024-10-10T10:29:08Z

The 64bit version did not have a stub_syscall1 function yet. Add it as it will be useful to implement a static binary for stub loading. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240919124511.282088-2-benjamin@sipsolutions.net Signed-off-by: Johannes Berg

um: remove copy_context_skas0

2024-07-03T15:09:49Z

The kernel flushes the memory ranges anyway for CoW and does not assume that the userspace process has anything set up already. So, start with a fresh process for the new mm context. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240703134536.1161108-8-benjamin@sipsolutions.net Signed-off-by: Johannes Berg

um: Rework syscall handling

2024-07-03T15:09:49Z

Rework syscall handling to be platform independent. Also create a clean split between queueing of syscalls and flushing them out, removing the need to keep state in the code that triggers the syscalls. The code adds syscall_data_len to the global mm_id structure. This will be used later to allow surrounding code to track whether syscalls still need to run and if errors occurred. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240703134536.1161108-5-benjamin@sipsolutions.net Signed-off-by: Johannes Berg

um: Add generic stub_syscall6 function

2024-07-03T15:09:49Z

This function will be used by the new syscall handling code. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240703134536.1161108-4-benjamin@sipsolutions.net Signed-off-by: Johannes Berg

um: Remove stub-data.h include from common-offsets.h

2024-07-03T15:09:48Z

Further commits will require values from common-offsets.h inside stub-data.h. Resolve the possible circular dependency and simply use offsetof() inside stub_32.h and stub_64.h. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240703134536.1161108-2-benjamin@sipsolutions.net Signed-off-by: Johannes Berg

um: Fix the -Wmissing-prototypes warning for get_thread_reg

2024-04-30T12:15:17Z

The get_thread_reg function is defined in the user code, and is called by the kernel code. It should be declared in a shared header. Fixes: dbba7f704aa0 ("um: stop polluting the namespace with registers.h contents") Signed-off-by: Tiwei Bie Signed-off-by: Richard Weinberger

um: Fix -Wmissing-prototypes warnings for __warp_* and foo

2024-04-22T19:58:48Z

These functions are not called explicitly. Let's just workaround the -Wmissing-prototypes warnings by declaring them locally similar to what was done in arch/x86/kernel/asm-offsets_32.c. This will address below -Wmissing-prototypes warnings: ./arch/x86/um/shared/sysdep/kernel-offsets.h:9:6: warning: no previous prototype for ‘foo’ [-Wmissing-prototypes] arch/um/os-Linux/main.c:187:7: warning: no previous prototype for ‘__wrap_malloc’ [-Wmissing-prototypes] arch/um/os-Linux/main.c:208:7: warning: no previous prototype for ‘__wrap_calloc’ [-Wmissing-prototypes] arch/um/os-Linux/main.c:222:6: warning: no previous prototype for ‘__wrap_free’ [-Wmissing-prototypes] arch/x86/um/user-offsets.c:17:6: warning: no previous prototype for ‘foo’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie Signed-off-by: Richard Weinberger