kernel/arch/um/include/shared/registers.h, branch linux-rolling-stable

um: always use the internal copy of the FP registers

2024-10-10T10:03:55Z

When switching from userspace to the kernel, all registers including the FP registers are copied into the kernel and restored later on. As such, the true source for the FP register state is actually already in the kernel and they should never be grabbed from the userspace process. Change the various places to simply copy the data from the internal FP register storage area. Note that on i386 the format of PTRACE_GETFPREGS and PTRACE_GETFPXREGS is different enough that conversion would be needed. With this patch, -EINVAL is returned if the non-native format is requested. The upside is, that this patchset fixes setting registers via ptrace (which simply did not work before) as well as fixing setting floating point registers using the mcontext on signal return on i386. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240913133845.964292-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg

um: Remove unused register save/restore functions

2024-01-05T15:28:57Z

These functions were only used when calling PTRACE_ARCH_PRCTL, but this code has been removed. Signed-off-by: Benjamin Berg Signed-off-by: Richard Weinberger

um: stop polluting the namespace with registers.h contents

2021-12-21T20:31:35Z

Only one extern in there is needed in processor-generic.h, and it's not needed anywhere else. So move it over there and get rid of the include in processor-generic.h, adding includes of registers.h to the few files that need the declarations in it. Signed-off-by: Al Viro Signed-off-by: Richard Weinberger

um: registers: Rename function names to avoid conflicts and build problems

2021-12-21T20:22:19Z

The function names init_registers() and restore_registers() are used in several net/ethernet/ and gpu/drm/ drivers for other purposes (not calls to UML functions), so rename them. This fixes multiple build errors. Signed-off-by: Randy Dunlap Cc: Jeff Dike Cc: Richard Weinberger Cc: Anton Ivanov Cc: linux-um@lists.infradead.org Signed-off-by: Richard Weinberger

um: Add SPDX headers for files in arch/um/include

2019-09-15T19:37:17Z

Convert files to use SPDX header. All files are licensed under the GPLv2. Signed-off-by: Alex Dewar Signed-off-by: Richard Weinberger

um: add extended processor state save/restore support

2016-05-21T21:38:06Z

This patch extends save_fp_registers() and restore_fp_registers() to use PTRACE_GETREGSET and PTRACE_SETREGSET with the XSTATE note type, adding support for new processor state extensions between context switches. When the new ptrace requests are unavailable, it falls back to the old PTRACE_GETFPREGS and PTRACE_SETFPREGS methods, which have been renamed to save_i387_registers() and restore_i387_registers(). Now these functions expect *fp_regs to have the space of an _xstate struct. Thus, this also makes ptrace in UML responde to PTRACE_GETFPREGS/_SETFPREG requests with a user_i387_struct (thus independent from HOST_FP_SIZE), and by calling save_i387_registers() and restore_i387_registers() instead of the extended save_fp_registers() and restore_fp_registers() functions. Signed-off-by: Eli Cooper

um: get rid of pointless include "..." where include <...> will do

2012-10-09T20:28:45Z

Signed-off-by: Al Viro Signed-off-by: Richard Weinberger

um: Save FPU registers between task switches

2011-09-15T01:09:37Z

Some time ago Jeff prepared 42daba316557 ("uml: stop saving process FP state") for UML to stop saving the process FP state between task switches. The assumption was that since with SKAS0 every guest process runs inside a host process context the host OS will take care of keeping the proper FP state. Unfortunately this is not true for multi-threaded applications, where all guest threads share a single host process context yet all may use the FPU on their own. Although I haven't verified it I suspect things to be even worse in SKAS3 mode where all guest processes run inside a single host process. The patch reintroduces the saving and restoring of the FP context between task switches. [richard@nod.at: Ingo posted this patch in 2009, sadly it was never applied and got lost. Now in 2011 the problem was reported by Gunnar.] Signed-off-by: Ingo van Lil Signed-off-by: Richard Weinberger Reported-by: Tested-by: Cc: Stanislav Meduna Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

x86, um: take arch/um/include/* out of the way

2008-10-23T05:55:19Z

We can't just plop asm/* into it - userland helpers are built with it in search path and seeing asm/* show up there suddenly would be a bad idea. Signed-off-by: Al Viro Signed-off-by: H. Peter Anvin