diff options
| -rw-r--r-- | arch/x86/kernel/signal.c | 86 |
1 files changed, 36 insertions, 50 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 53ac66b3fd9b..83563e98f0be 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -47,24 +47,6 @@ #include <asm/sigframe.h> #include <asm/signal.h> -#define COPY(x) do { \ - get_user_ex(regs->x, &sc->x); \ -} while (0) - -#define GET_SEG(seg) ({ \ - unsigned short tmp; \ - get_user_ex(tmp, &sc->seg); \ - tmp; \ -}) - -#define COPY_SEG(seg) do { \ - regs->seg = GET_SEG(seg); \ -} while (0) - -#define COPY_SEG_CPL3(seg) do { \ - regs->seg = GET_SEG(seg) | 3; \ -} while (0) - #ifdef CONFIG_X86_64 /* * If regs->ss will cause an IRET fault, change it. Otherwise leave it @@ -92,53 +74,58 @@ static void force_valid_ss(struct pt_regs *regs) ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN)) regs->ss = __USER_DS; } +# define CONTEXT_COPY_SIZE offsetof(struct sigcontext, reserved1) +#else +# define CONTEXT_COPY_SIZE sizeof(struct sigcontext) #endif static int restore_sigcontext(struct pt_regs *regs, - struct sigcontext __user *sc, + struct sigcontext __user *usc, unsigned long uc_flags) { - unsigned long buf_val; - void __user *buf; - unsigned int tmpflags; - unsigned int err = 0; + struct sigcontext sc; /* Always make any pending restarted system calls return -EINTR */ current->restart_block.fn = do_no_restart_syscall; - get_user_try { + if (copy_from_user(&sc, usc, CONTEXT_COPY_SIZE)) + return -EFAULT; #ifdef CONFIG_X86_32 - set_user_gs(regs, GET_SEG(gs)); - COPY_SEG(fs); - COPY_SEG(es); - COPY_SEG(ds); + set_user_gs(regs, sc.gs); + regs->fs = sc.fs; + regs->es = sc.es; + regs->ds = sc.ds; #endif /* CONFIG_X86_32 */ - COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); - COPY(dx); COPY(cx); COPY(ip); COPY(ax); + regs->bx = sc.bx; + regs->cx = sc.cx; + regs->dx = sc.dx; + regs->si = sc.si; + regs->di = sc.di; + regs->bp = sc.bp; + regs->ax = sc.ax; + regs->sp = sc.sp; + regs->ip = sc.ip; #ifdef CONFIG_X86_64 - COPY(r8); - COPY(r9); - COPY(r10); - COPY(r11); - COPY(r12); - COPY(r13); - COPY(r14); - COPY(r15); + regs->r8 = sc.r8; + regs->r9 = sc.r9; + regs->r10 = sc.r10; + regs->r11 = sc.r11; + regs->r12 = sc.r12; + regs->r13 = sc.r13; + regs->r14 = sc.r14; + regs->r15 = sc.r15; #endif /* CONFIG_X86_64 */ - COPY_SEG_CPL3(cs); - COPY_SEG_CPL3(ss); - - get_user_ex(tmpflags, &sc->flags); - regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); - regs->orig_ax = -1; /* disable syscall checks */ + /* Get CS/SS and force CPL3 */ + regs->cs = sc.cs | 0x03; + regs->ss = sc.ss | 0x03; - get_user_ex(buf_val, &sc->fpstate); - buf = (void __user *)buf_val; - } get_user_catch(err); + regs->flags = (regs->flags & ~FIX_EFLAGS) | (sc.flags & FIX_EFLAGS); + /* disable syscall checks */ + regs->orig_ax = -1; #ifdef CONFIG_X86_64 /* @@ -149,9 +136,8 @@ static int restore_sigcontext(struct pt_regs *regs, force_valid_ss(regs); #endif - err |= fpu__restore_sig(buf, IS_ENABLED(CONFIG_X86_32)); - - return err; + return fpu__restore_sig((void __user *)sc.fpstate, + IS_ENABLED(CONFIG_X86_32)); } int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, |