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linux(4): Preserve fpu fxsave state across signal delivery on amd64.

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PR:			240768
Reviewed by:		kib
Differential Revision:	https://reviews.freebsd.org/D38302
MFC after:		1 week
This commit is contained in:
Dmitry Chagin 2023-02-02 20:21:37 +03:00
parent 69d94f4c76
commit a95cb95e12
2 changed files with 68 additions and 9 deletions
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70
sys/amd64/linux/linux_sysvec.c
View File

@ -319,21 +319,22 @@ int
linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
{
struct proc *p;
struct l_ucontext uc;
struct l_rt_sigframe sf;
struct l_sigcontext *context;
struct trapframe *regs;
mcontext_t mc;
unsigned long rflags;
sigset_t bmask;
int error;
int error, i;
ksiginfo_t ksi;
regs = td->td_frame;
error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc));
error = copyin((void *)regs->tf_rbx, &sf, sizeof(sf));
if (error != 0)
return (error);
p = td->td_proc;
context = &uc.uc_mcontext;
context = &sf.sf_uc.uc_mcontext;
rflags = context->sc_rflags;
/*
@ -372,7 +373,7 @@ linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
return (EINVAL);
}
linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
linux_to_bsd_sigset(&sf.sf_uc.uc_sigmask, &bmask);
kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
regs->tf_rdi = context->sc_rdi;
@ -396,6 +397,37 @@ linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
regs->tf_err = context->sc_err;
regs->tf_rflags = rflags;
if (sf.sf_uc.uc_mcontext.sc_fpstate != NULL) {
struct savefpu *svfp = (struct savefpu *)mc.mc_fpstate;
bzero(&mc, sizeof(mc));
mc.mc_ownedfp = _MC_FPOWNED_FPU;
mc.mc_fpformat = _MC_FPFMT_XMM;
svfp->sv_env.en_cw = sf.sf_fs.cwd;
svfp->sv_env.en_sw = sf.sf_fs.swd;
svfp->sv_env.en_tw = sf.sf_fs.twd;
svfp->sv_env.en_opcode = sf.sf_fs.fop;
svfp->sv_env.en_rip = sf.sf_fs.rip;
svfp->sv_env.en_rdp = sf.sf_fs.rdp;
svfp->sv_env.en_mxcsr = sf.sf_fs.mxcsr;
svfp->sv_env.en_mxcsr_mask = sf.sf_fs.mxcsr_mask;
/* FPU registers */
for (i = 0; i < nitems(svfp->sv_fp); ++i)
bcopy(&sf.sf_fs.st[i], svfp->sv_fp[i].fp_acc.fp_bytes,
sizeof(svfp->sv_fp[i].fp_acc.fp_bytes));
/* SSE registers */
for (i = 0; i < nitems(svfp->sv_xmm); ++i)
bcopy(&sf.sf_fs.xmm[i], svfp->sv_xmm[i].xmm_bytes,
sizeof(svfp->sv_xmm[i].xmm_bytes));
error = set_fpcontext(td, &mc, NULL, 0);
if (error != 0) {
uprintf("pid %d comm %s linux can't restore fpu state %d\n",
p->p_pid, p->p_comm, error);
return (error);
}
}
set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
return (EJUSTRETURN);
}
@ -414,8 +446,10 @@ linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
struct sigacts *psp;
caddr_t sp;
struct trapframe *regs;
struct savefpu *svfp;
mcontext_t mc;
int sig, code;
int oonstack, issiginfo;
int oonstack, issiginfo, i;
td = curthread;
p = td->td_proc;
@ -477,6 +511,29 @@ linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
mtx_unlock(&psp->ps_mtx);
PROC_UNLOCK(p);
get_fpcontext(td, &mc, NULL, NULL);
KASSERT(mc.mc_fpformat != _MC_FPFMT_NODEV, ("fpu not present"));
svfp = (struct savefpu *)mc.mc_fpstate;
sf.sf_fs.cwd = svfp->sv_env.en_cw;
sf.sf_fs.swd = svfp->sv_env.en_sw;
sf.sf_fs.twd = svfp->sv_env.en_tw;
sf.sf_fs.fop = svfp->sv_env.en_opcode;
sf.sf_fs.rip = svfp->sv_env.en_rip;
sf.sf_fs.rdp = svfp->sv_env.en_rdp;
sf.sf_fs.mxcsr = svfp->sv_env.en_mxcsr;
sf.sf_fs.mxcsr_mask = svfp->sv_env.en_mxcsr_mask;
/* FPU registers */
for (i = 0; i < nitems(svfp->sv_fp); ++i)
bcopy(svfp->sv_fp[i].fp_acc.fp_bytes, &sf.sf_fs.st[i],
sizeof(svfp->sv_fp[i].fp_acc.fp_bytes));
/* SSE registers */
for (i = 0; i < nitems(svfp->sv_xmm); ++i)
bcopy(svfp->sv_xmm[i].xmm_bytes, &sf.sf_fs.xmm[i],
sizeof(svfp->sv_xmm[i].xmm_bytes));
sf.sf_uc.uc_mcontext.sc_fpstate = (struct l_fpstate *)((caddr_t)sfp +
offsetof(struct l_rt_sigframe, sf_fs));
/* Translate the signal. */
sig = bsd_to_linux_signal(sig);
/* Fill in POSIX parts. */
@ -490,6 +547,7 @@ linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
sigexit(td, SIGILL);
}
fpstate_drop(td);
/* Build the argument list for the signal handler. */
regs->tf_rdi = sig; /* arg 1 in %rdi */
regs->tf_rax = 0;

7
sys/x86/linux/linux_x86_sigframe.h
View File

@ -138,10 +138,10 @@ struct l_fpstate {
u_int64_t rdp;
u_int32_t mxcsr;
u_int32_t mxcsr_mask;
u_int32_t st_space[32];
u_int32_t xmm_space[64];
u_int8_t st[8][16];
u_int8_t xmm[16][16];
u_int32_t reserved2[24];
};
} __aligned(16);
struct l_sigcontext {
l_ulong sc_r8;
@ -189,6 +189,7 @@ struct l_ucontext {
struct l_rt_sigframe {
struct l_ucontext sf_uc;
struct l_siginfo sf_si;
struct l_fpstate sf_fs;
};
#endif /* __i386__ || (__amd64__ && COMPAT_LINUX32) */