hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

um: fix FPU state preservation around signal handlers 

This patch makes UML saves/restores FPU state from/to the fpstate in
pt_regs when setting up or returning from a signal stack, rather than
calling ptrace directly. This ensures that FPU state is correctly
preserved around signal handlers in a multi-threaded scenario.

Signed-off-by: Eli Cooper <elicooper@gmx.com>
This commit is contained in:
Eli Cooper 2016-03-20 00:58:39 +08:00 committed by Richard Weinberger
parent 44549e8f5e
commit 6de5a8a500
1 changed files with 3 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
arch/x86/um/signal.c
View File

@ -225,20 +225,10 @@ static int copy_sc_from_user(struct pt_regs *regs,
} else
#endif
{
struct user_i387_struct fp;
err = copy_from_user(&fp, (void *)sc.fpstate,
err = copy_from_user(regs->regs.fp, (void *)sc.fpstate,
sizeof(struct user_i387_struct));
if (err)
return 1;
err = restore_fp_registers(pid, (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;
}
@ -325,10 +315,8 @@ static int copy_sc_to_user(struct sigcontext __user *to,
} else
#endif
{
struct user_i387_struct fp;
err = save_fp_registers(pid, (unsigned long *) &fp);
if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
if (copy_to_user(to_fp, regs->regs.fp,
sizeof(struct user_i387_struct)))
return 1;
}