Cregit: Linux 6.15: mcontext.c

Contributors: 6
Author	Tokens	Token Proportion	Commits	Commit Proportion
Al Viro	264	77.19%	4	30.77%
Johannes Berg	52	15.20%	1	7.69%
Jeff Dike	14	4.09%	5	38.46%
Benjamin Berg	8	2.34%	1	7.69%
Tiwei Bie	3	0.88%	1	7.69%
Greg Kroah-Hartman	1	0.29%	1	7.69%
Total	342		13

// SPDX-License-Identifier: GPL-2.0
#include <sys/ucontext.h>
#define __FRAME_OFFSETS
#include <asm/ptrace.h>
#include <sysdep/ptrace.h>
#include <sysdep/mcontext.h>
#include <arch.h>

void get_regs_from_mc(struct uml_pt_regs *regs, mcontext_t *mc)
{
#ifdef __i386__
#define COPY2(X,Y) regs->gp[X] = mc->gregs[REG_##Y]
#define COPY(X) regs->gp[X] = mc->gregs[REG_##X]
#define COPY_SEG(X) regs->gp[X] = mc->gregs[REG_##X] & 0xffff;
#define COPY_SEG_CPL3(X) regs->gp[X] = (mc->gregs[REG_##X] & 0xffff) | 3;
	COPY_SEG(GS); COPY_SEG(FS); COPY_SEG(ES); COPY_SEG(DS);
	COPY(EDI); COPY(ESI); COPY(EBP);
	COPY2(UESP, ESP); /* sic */
	COPY(EBX); COPY(EDX); COPY(ECX); COPY(EAX);
	COPY(EIP); COPY_SEG_CPL3(CS); COPY(EFL); COPY_SEG_CPL3(SS);
#else
#define COPY2(X,Y) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##Y]
#define COPY(X) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##X]
	COPY(R8); COPY(R9); COPY(R10); COPY(R11);
	COPY(R12); COPY(R13); COPY(R14); COPY(R15);
	COPY(RDI); COPY(RSI); COPY(RBP); COPY(RBX);
	COPY(RDX); COPY(RAX); COPY(RCX); COPY(RSP);
	COPY(RIP);
	COPY2(EFLAGS, EFL);
	COPY2(CS, CSGSFS);
	regs->gp[SS / sizeof(unsigned long)] = mc->gregs[REG_CSGSFS] >> 48;
#endif
}

void mc_set_rip(void *_mc, void *target)
{
	mcontext_t *mc = _mc;

#ifdef __i386__
	mc->gregs[REG_EIP] = (unsigned long)target;
#else
	mc->gregs[REG_RIP] = (unsigned long)target;
#endif
}