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authorJeff Dike <jdike@addtoit.com>2007-10-16 01:27:15 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 09:43:07 -0700
commita5f6096c805e6d2fa03ee932f8c70af34cee41a0 (patch)
treec74d984c0e2fc2958425df65605dd3451adc6520 /arch
parent189872f968def833727b6bfef83ebd7440c538e6 (diff)
uml: floating point signal delivery fixes
Handle floating point state in across signals correctly. UML/i386 needs to know whether the host does PTRACE_[GS]ETFPXREGS, so an arch_init_registers hook is added, which on x86_64 does nothing. UML doesn't save and restore floating point registers on kernel entry and exit, so they need to be copied between the host process and the sigcontext. save_fpx_registers and restore_fpx_registers are added for this purpose. save_fp_registers and restore_fp_registers already exist. There was a bunch of floating point state conversion code in arch/um/sys-i386/ptrace.c which isn't needed there, but is needed in signal.c, so it is moved over. The i386 code now distinguishes between fp and fpx state and handles them correctly. The x86_64 code just needs to copy state as-is between the host process and the stack. There are also some fixes there to pass the correct address of the floating point state around. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/um/include/registers.h2
-rw-r--r--arch/um/include/sysdep-i386/ptrace.h2
-rw-r--r--arch/um/include/sysdep-x86_64/ptrace.h4
-rw-r--r--arch/um/os-Linux/registers.c2
-rw-r--r--arch/um/os-Linux/sys-i386/registers.c35
-rw-r--r--arch/um/sys-i386/ptrace.c79
-rw-r--r--arch/um/sys-i386/signal.c223
-rw-r--r--arch/um/sys-x86_64/signal.c53
8 files changed, 284 insertions, 116 deletions
diff --git a/arch/um/include/registers.h b/arch/um/include/registers.h
index 8e8ea9651189..0e27406a43a4 100644
--- a/arch/um/include/registers.h
+++ b/arch/um/include/registers.h
@@ -12,6 +12,8 @@
extern void init_thread_registers(struct uml_pt_regs *to);
extern int save_fp_registers(int pid, unsigned long *fp_regs);
extern int restore_fp_registers(int pid, unsigned long *fp_regs);
+extern int save_fpx_registers(int pid, unsigned long *fp_regs);
+extern int restore_fpx_registers(int pid, unsigned long *fp_regs);
extern void save_registers(int pid, struct uml_pt_regs *regs);
extern void restore_registers(int pid, struct uml_pt_regs *regs);
extern void init_registers(int pid);
diff --git a/arch/um/include/sysdep-i386/ptrace.h b/arch/um/include/sysdep-i386/ptrace.h
index edb9393283b5..c16d739d2089 100644
--- a/arch/um/include/sysdep-i386/ptrace.h
+++ b/arch/um/include/sysdep-i386/ptrace.h
@@ -168,4 +168,6 @@ struct syscall_args {
#define UPT_FAULTINFO(r) (&(r)->faultinfo)
+extern void arch_init_registers(int pid);
+
#endif
diff --git a/arch/um/include/sysdep-x86_64/ptrace.h b/arch/um/include/sysdep-x86_64/ptrace.h
index 2ae04480ac81..7848b7dce715 100644
--- a/arch/um/include/sysdep-x86_64/ptrace.h
+++ b/arch/um/include/sysdep-x86_64/ptrace.h
@@ -234,4 +234,8 @@ struct syscall_args {
#define UPT_FAULTINFO(r) (&(r)->faultinfo)
+static inline void arch_init_registers(int pid)
+{
+}
+
#endif
diff --git a/arch/um/os-Linux/registers.c b/arch/um/os-Linux/registers.c
index b06c780e8dba..a32ba6ab1211 100644
--- a/arch/um/os-Linux/registers.c
+++ b/arch/um/os-Linux/registers.c
@@ -47,6 +47,8 @@ void init_registers(int pid)
if (err)
panic("check_ptrace : PTRACE_GETREGS failed, errno = %d",
errno);
+
+ arch_init_registers(pid);
}
void get_safe_registers(unsigned long *regs)
diff --git a/arch/um/os-Linux/sys-i386/registers.c b/arch/um/os-Linux/sys-i386/registers.c
index f171204caa4e..8f1f0ab639b9 100644
--- a/arch/um/os-Linux/sys-i386/registers.c
+++ b/arch/um/os-Linux/sys-i386/registers.c
@@ -8,9 +8,6 @@
#include "longjmp.h"
#include "user.h"
-/* XXX These need to use [GS]ETFPXREGS and copy_sc_{to,from}_user_skas needs
- * to pass in a sufficiently large buffer
- */
int save_fp_registers(int pid, unsigned long *fp_regs)
{
if(ptrace(PTRACE_GETFPREGS, pid, 0, fp_regs) < 0)
@@ -25,6 +22,20 @@ int restore_fp_registers(int pid, unsigned long *fp_regs)
return 0;
}
+int save_fpx_registers(int pid, unsigned long *fp_regs)
+{
+ if(ptrace(PTRACE_GETFPXREGS, pid, 0, fp_regs) < 0)
+ return -errno;
+ return 0;
+}
+
+int restore_fpx_registers(int pid, unsigned long *fp_regs)
+{
+ if(ptrace(PTRACE_SETFPXREGS, pid, 0, fp_regs) < 0)
+ return -errno;
+ return 0;
+}
+
unsigned long get_thread_reg(int reg, jmp_buf *buf)
{
switch(reg){
@@ -36,3 +47,21 @@ unsigned long get_thread_reg(int reg, jmp_buf *buf)
return 0;
}
}
+
+int have_fpx_regs = 1;
+
+void arch_init_registers(int pid)
+{
+ unsigned long fpx_regs[HOST_XFP_SIZE];
+ int err;
+
+ err = ptrace(PTRACE_GETFPXREGS, pid, 0, fpx_regs);
+ if(!err)
+ return;
+
+ if(errno != EIO)
+ panic("check_ptrace : PTRACE_GETFPXREGS failed, errno = %d",
+ errno);
+
+ have_fpx_regs = 0;
+}
diff --git a/arch/um/sys-i386/ptrace.c b/arch/um/sys-i386/ptrace.c
index 178f894384f4..cb899dd1c6b5 100644
--- a/arch/um/sys-i386/ptrace.c
+++ b/arch/um/sys-i386/ptrace.c
@@ -144,85 +144,6 @@ int peek_user(struct task_struct *child, long addr, long data)
return put_user(tmp, (unsigned long __user *) data);
}
-struct i387_fxsave_struct {
- unsigned short cwd;
- unsigned short swd;
- unsigned short twd;
- unsigned short fop;
- long fip;
- long fcs;
- long foo;
- long fos;
- long mxcsr;
- long reserved;
- long st_space[32]; /* 8*16 bytes for each FP-reg = 128 bytes */
- long xmm_space[32]; /* 8*16 bytes for each XMM-reg = 128 bytes */
- long padding[56];
-};
-
-/*
- * FPU tag word conversions.
- */
-
-static inline unsigned short twd_i387_to_fxsr( unsigned short twd )
-{
- unsigned int tmp; /* to avoid 16 bit prefixes in the code */
-
- /* Transform each pair of bits into 01 (valid) or 00 (empty) */
- tmp = ~twd;
- tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
- /* and move the valid bits to the lower byte. */
- tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
- tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
- tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
- return tmp;
-}
-
-static inline unsigned long twd_fxsr_to_i387( struct i387_fxsave_struct *fxsave )
-{
- struct _fpxreg *st = NULL;
- unsigned long twd = (unsigned long) fxsave->twd;
- unsigned long tag;
- unsigned long ret = 0xffff0000;
- int i;
-
-#define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16);
-
- for ( i = 0 ; i < 8 ; i++ ) {
- if ( twd & 0x1 ) {
- st = (struct _fpxreg *) FPREG_ADDR( fxsave, i );
-
- switch ( st->exponent & 0x7fff ) {
- case 0x7fff:
- tag = 2; /* Special */
- break;
- case 0x0000:
- if ( !st->significand[0] &&
- !st->significand[1] &&
- !st->significand[2] &&
- !st->significand[3] ) {
- tag = 1; /* Zero */
- } else {
- tag = 2; /* Special */
- }
- break;
- default:
- if ( st->significand[3] & 0x8000 ) {
- tag = 0; /* Valid */
- } else {
- tag = 2; /* Special */
- }
- break;
- }
- } else {
- tag = 3; /* Empty */
- }
- ret |= (tag << (2 * i));
- twd = twd >> 1;
- }
- return ret;
-}
-
static inline int convert_fxsr_to_user(struct _fpstate __user *buf,
struct pt_regs *regs)
{
diff --git a/arch/um/sys-i386/signal.c b/arch/um/sys-i386/signal.c
index 1eb21a023e33..0147227ce18d 100644
--- a/arch/um/sys-i386/signal.c
+++ b/arch/um/sys-i386/signal.c
@@ -32,25 +32,186 @@ void copy_sc(struct uml_pt_regs *regs, void *from)
REGS_SS(regs->gp) = sc->ss;
}
+/*
+ * FPU tag word conversions.
+ */
+
+static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
+{
+ unsigned int tmp; /* to avoid 16 bit prefixes in the code */
+
+ /* Transform each pair of bits into 01 (valid) or 00 (empty) */
+ tmp = ~twd;
+ tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
+ /* and move the valid bits to the lower byte. */
+ tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
+ tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
+ tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
+ return tmp;
+}
+
+static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
+{
+ struct _fpxreg *st = NULL;
+ unsigned long twd = (unsigned long) fxsave->twd;
+ unsigned long tag;
+ unsigned long ret = 0xffff0000;
+ int i;
+
+#define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16);
+
+ for (i = 0; i < 8; i++) {
+ if (twd & 0x1) {
+ st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);
+
+ switch (st->exponent & 0x7fff) {
+ case 0x7fff:
+ tag = 2; /* Special */
+ break;
+ case 0x0000:
+ if ( !st->significand[0] &&
+ !st->significand[1] &&
+ !st->significand[2] &&
+ !st->significand[3] ) {
+ tag = 1; /* Zero */
+ } else {
+ tag = 2; /* Special */
+ }
+ break;
+ default:
+ if (st->significand[3] & 0x8000) {
+ tag = 0; /* Valid */
+ } else {
+ tag = 2; /* Special */
+ }
+ break;
+ }
+ } else {
+ tag = 3; /* Empty */
+ }
+ ret |= (tag << (2 * i));
+ twd = twd >> 1;
+ }
+ return ret;
+}
+
+static int convert_fxsr_to_user(struct _fpstate __user *buf,
+ struct user_fxsr_struct *fxsave)
+{
+ unsigned long env[7];
+ struct _fpreg __user *to;
+ struct _fpxreg *from;
+ int i;
+
+ env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
+ env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
+ env[2] = twd_fxsr_to_i387(fxsave);
+ env[3] = fxsave->fip;
+ env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
+ env[5] = fxsave->foo;
+ env[6] = fxsave->fos;
+
+ if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
+ return 1;
+
+ to = &buf->_st[0];
+ from = (struct _fpxreg *) &fxsave->st_space[0];
+ for (i = 0; i < 8; i++, to++, from++) {
+ unsigned long __user *t = (unsigned long __user *)to;
+ unsigned long *f = (unsigned long *)from;
+
+ if (__put_user(*f, t) ||
+ __put_user(*(f + 1), t + 1) ||
+ __put_user(from->exponent, &to->exponent))
+ return 1;
+ }
+ return 0;
+}
+
+static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
+ struct _fpstate __user *buf)
+{
+ unsigned long env[7];
+ struct _fpxreg *to;
+ struct _fpreg __user *from;
+ int i;
+
+ if (copy_from_user( env, buf, 7 * sizeof(long)))
+ return 1;
+
+ fxsave->cwd = (unsigned short)(env[0] & 0xffff);
+ fxsave->swd = (unsigned short)(env[1] & 0xffff);
+ fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
+ fxsave->fip = env[3];
+ fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
+ fxsave->fcs = (env[4] & 0xffff);
+ fxsave->foo = env[5];
+ fxsave->fos = env[6];
+
+ to = (struct _fpxreg *) &fxsave->st_space[0];
+ from = &buf->_st[0];
+ for (i = 0; i < 8; i++, to++, from++) {
+ unsigned long *t = (unsigned long *)to;
+ unsigned long __user *f = (unsigned long __user *)from;
+
+ if (__get_user(*t, f) ||
+ __get_user(*(t + 1), f + 1) ||
+ __get_user(to->exponent, &from->exponent))
+ return 1;
+ }
+ return 0;
+}
+
+extern int have_fpx_regs;
+
static int copy_sc_from_user(struct pt_regs *regs,
struct sigcontext __user *from)
{
- struct sigcontext sc;
- unsigned long fpregs[HOST_FP_SIZE];
+ struct sigcontext sc;
int err;
err = copy_from_user(&sc, from, sizeof(sc));
- err |= copy_from_user(fpregs, sc.fpstate, sizeof(fpregs));
if (err)
return err;
copy_sc(&regs->regs, &sc);
-
- err = restore_fp_registers(userspace_pid[0], fpregs);
- if (err < 0) {
- printk(KERN_ERR "copy_sc_from_user_skas - PTRACE_SETFPREGS "
- "failed, errno = %d\n", -err);
- return err;
+ if (have_fpx_regs) {
+ struct user_fxsr_struct fpx;
+
+ err = copy_from_user(&fpx, &sc.fpstate->_fxsr_env[0],
+ sizeof(struct user_fxsr_struct));
+ if (err)
+ return 1;
+
+ err = convert_fxsr_from_user(&fpx, sc.fpstate);
+ if (err)
+ return 1;
+
+ err = restore_fpx_registers(userspace_pid[current_thread->cpu],
+ (unsigned long *) &fpx);
+ if (err < 0) {
+ printk(KERN_ERR "copy_sc_from_user - "
+ "restore_fpx_registers failed, errno = %d\n",
+ -err);
+ return 1;
+ }
+ }
+ else {
+ struct user_i387_struct fp;
+
+ err = copy_from_user(&fp, sc.fpstate,
+ sizeof(struct user_i387_struct));
+ if (err)
+ return 1;
+
+ err = restore_fp_registers(userspace_pid[current_thread->cpu],
+ (unsigned long *) &fp);
+ if (err < 0) {
+ printk(KERN_ERR "copy_sc_from_user - "
+ "restore_fp_registers failed, errno = %d\n",
+ -err);
+ return 1;
+ }
}
return 0;
@@ -61,7 +222,6 @@ static int copy_sc_to_user(struct sigcontext __user *to,
unsigned long sp)
{
struct sigcontext sc;
- unsigned long fpregs[HOST_FP_SIZE];
struct faultinfo * fi = &current->thread.arch.faultinfo;
int err;
@@ -86,20 +246,43 @@ static int copy_sc_to_user(struct sigcontext __user *to,
sc.err = fi->error_code;
sc.trapno = fi->trap_no;
- err = save_fp_registers(userspace_pid[0], fpregs);
- if (err < 0) {
- printk(KERN_ERR "copy_sc_to_user_skas - PTRACE_GETFPREGS "
- "failed, errno = %d\n", err);
- return 1;
- }
to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
sc.fpstate = to_fp;
- if (err)
- return err;
+ if (have_fpx_regs) {
+ struct user_fxsr_struct fpx;
+
+ err = save_fpx_registers(userspace_pid[current_thread->cpu],
+ (unsigned long *) &fpx);
+ if (err < 0){
+ printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
+ "failed, errno = %d\n", err);
+ return 1;
+ }
+
+ err = convert_fxsr_to_user(to_fp, &fpx);
+ if (err)
+ return 1;
+
+ err |= __put_user(fpx.swd, &to_fp->status);
+ err |= __put_user(X86_FXSR_MAGIC, &to_fp->magic);
+ if (err)
+ return 1;
+
+ if (copy_to_user(&to_fp->_fxsr_env[0], &fpx,
+ sizeof(struct user_fxsr_struct)))
+ return 1;
+ }
+ else {
+ struct user_i387_struct fp;
+
+ err = save_fp_registers(userspace_pid[current_thread->cpu],
+ (unsigned long *) &fp);
+ if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
+ return 1;
+ }
- return copy_to_user(to, &sc, sizeof(sc)) ||
- copy_to_user(to_fp, fpregs, sizeof(fpregs));
+ return copy_to_user(to, &sc, sizeof(sc));
}
static int copy_ucontext_to_user(struct ucontext __user *uc,
diff --git a/arch/um/sys-x86_64/signal.c b/arch/um/sys-x86_64/signal.c
index c98dd7f31396..a8e5fd7b2adb 100644
--- a/arch/um/sys-x86_64/signal.c
+++ b/arch/um/sys-x86_64/signal.c
@@ -42,8 +42,10 @@ void copy_sc(struct uml_pt_regs *regs, void *from)
}
static int copy_sc_from_user(struct pt_regs *regs,
- struct sigcontext __user *from)
+ struct sigcontext __user *from,
+ struct _fpstate __user *fpp)
{
+ struct user_i387_struct fp;
int err = 0;
#define GETREG(regs, regno, sc, regname) \
@@ -69,10 +71,25 @@ static int copy_sc_from_user(struct pt_regs *regs,
err |= GETREG(regs, RIP, from, rip);
err |= GETREG(regs, EFLAGS, from, eflags);
err |= GETREG(regs, CS, from, cs);
+ if (err)
+ return 1;
#undef GETREG
- return err;
+ err = copy_from_user(&fp, fpp, sizeof(struct user_i387_struct));
+ if (err)
+ return 1;
+
+ err = restore_fp_registers(userspace_pid[current_thread->cpu],
+ (unsigned long *) &fp);
+ if (err < 0) {
+ printk(KERN_ERR "copy_sc_from_user - "
+ "restore_fp_registers failed, errno = %d\n",
+ -err);
+ return 1;
+ }
+
+ return 0;
}
static int copy_sc_to_user(struct sigcontext __user *to,
@@ -80,6 +97,7 @@ static int copy_sc_to_user(struct sigcontext __user *to,
unsigned long mask, unsigned long sp)
{
struct faultinfo * fi = &current->thread.arch.faultinfo;
+ struct user_i387_struct fp;
int err = 0;
err |= __put_user(0, &to->gs);
@@ -120,6 +138,19 @@ static int copy_sc_to_user(struct sigcontext __user *to,
#undef PUTREG
err |= __put_user(mask, &to->oldmask);
+ if (err)
+ return 1;
+
+ err = save_fp_registers(userspace_pid[current_thread->cpu],
+ (unsigned long *) &fp);
+ if (err < 0) {
+ printk(KERN_ERR "copy_sc_from_user - restore_fp_registers "
+ "failed, errno = %d\n", -err);
+ return 1;
+ }
+
+ if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
+ return 1;
return(err);
}
@@ -129,6 +160,7 @@ struct rt_sigframe
char __user *pretcode;
struct ucontext uc;
struct siginfo info;
+ struct _fpstate fpstate;
};
#define round_down(m, n) (((m) / (n)) * (n))
@@ -138,7 +170,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
siginfo_t *info, sigset_t *set)
{
struct rt_sigframe __user *frame;
- struct _fpstate __user *fp = NULL;
unsigned long save_sp = PT_REGS_RSP(regs);
int err = 0;
struct task_struct *me = current;
@@ -148,13 +179,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
/* Subtract 128 for a red zone and 8 for proper alignment */
frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
- if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
- goto out;
-
-#if 0 /* XXX */
- if (save_i387(fp) < 0)
- err |= -1;
-#endif
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto out;
@@ -181,9 +205,9 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
err |= __put_user(sas_ss_flags(save_sp),
&frame->uc.uc_stack.ss_flags);
err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
- err |= copy_sc_to_user(&frame->uc.uc_mcontext, fp, regs, set->sig[0],
- save_sp);
- err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
+ err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
+ set->sig[0], save_sp);
+ err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);
if (sizeof(*set) == 16) {
__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
@@ -246,7 +270,8 @@ long sys_rt_sigreturn(struct pt_regs *regs)
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
- if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
+ if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext,
+ &frame->fpstate))
goto segfault;
/* Avoid ERESTART handling */

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