x86: get rid of put_user_try in {ia32,x32}_setup_rt_frame() (39f16c1c) · Commits · 戴 / test

arch/x86/ia32/ia32_signal.c

+26 −24

Original line number	Diff line number	Diff line
		@@ -326,35 +326,34 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,

		frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);

		if (!access_ok(frame, sizeof(*frame)))
		if (!user_access_begin(frame, sizeof(*frame)))
		return -EFAULT;

		put_user_try {
		put_user_ex(sig, &frame->sig);
		put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
		put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
		unsafe_put_user(sig, &frame->sig, Efault);
		unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault);
		unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault);

		/* Create the ucontext. */
		if (static_cpu_has(X86_FEATURE_XSAVE))
		put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
		unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
		else
		put_user_ex(0, &frame->uc.uc_flags);
		put_user_ex(0, &frame->uc.uc_link);
		compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
		unsafe_put_user(0, &frame->uc.uc_flags, Efault);
		unsafe_put_user(0, &frame->uc.uc_link, Efault);
		unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);

		if (ksig->ka.sa.sa_flags & SA_RESTORER)
		restorer = ksig->ka.sa.sa_restorer;
		else
		restorer = current->mm->context.vdso +
		vdso_image_32.sym___kernel_rt_sigreturn;
		put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
		unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);

		/*
		* Not actually used anymore, but left because some gdb
		* versions need it.
		*/
		put_user_ex(((u64 )&code), (u64 __user *)frame->retcode);
		} put_user_catch(err);
		unsafe_put_user(((u64 )&code), (u64 __user *)frame->retcode, Efault);
		user_access_end();

		err \|= __copy_siginfo_to_user32(&frame->info, &ksig->info, false);
		err \|= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
		@@ -380,4 +379,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
		regs->ss = __USER32_DS;

		return 0;
		Efault:
		user_access_end();
		return -EFAULT;
		}

arch/x86/kernel/signal.c

+18 −15

Original line number	Diff line number	Diff line
		@@ -529,6 +529,9 @@ static int x32_setup_rt_frame(struct ksignal *ksig,
		int err = 0;
		void __user *fpstate = NULL;

		if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
		return -EFAULT;

		frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);

		if (!access_ok(frame, sizeof(*frame)))
		@@ -541,22 +544,17 @@ static int x32_setup_rt_frame(struct ksignal *ksig,

		uc_flags = frame_uc_flags(regs);

		put_user_try {
		/* Create the ucontext. */
		put_user_ex(uc_flags, &frame->uc.uc_flags);
		put_user_ex(0, &frame->uc.uc_link);
		compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
		put_user_ex(0, &frame->uc.uc__pad0);
		if (!user_access_begin(frame, sizeof(*frame)))
		return -EFAULT;

		if (ksig->ka.sa.sa_flags & SA_RESTORER) {
		/* Create the ucontext. */
		unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault);
		unsafe_put_user(0, &frame->uc.uc_link, Efault);
		unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
		unsafe_put_user(0, &frame->uc.uc__pad0, Efault);
		restorer = ksig->ka.sa.sa_restorer;
		} else {
		/* could use a vstub here */
		restorer = NULL;
		err \|= -EFAULT;
		}
		put_user_ex(restorer, (unsigned long __user *)&frame->pretcode);
		} put_user_catch(err);
		unsafe_put_user(restorer, (unsigned long __user *)&frame->pretcode, Efault);
		user_access_end();

		err \|= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
		regs, set->sig[0]);
		@@ -582,6 +580,11 @@ static int x32_setup_rt_frame(struct ksignal *ksig,
		#endif /* CONFIG_X86_X32_ABI */

		return 0;
		#ifdef CONFIG_X86_X32_ABI
		Efault:
		user_access_end();
		return -EFAULT;
		#endif
		}

		/*

include/linux/compat.h

+5 −4

Original line number	Diff line number	Diff line
		@@ -483,12 +483,13 @@ extern void __user *compat_alloc_user_space(unsigned long len);

		int compat_restore_altstack(const compat_stack_t __user *uss);
		int __compat_save_altstack(compat_stack_t __user *, unsigned long);
		#define compat_save_altstack_ex(uss, sp) do { \
		#define unsafe_compat_save_altstack(uss, sp, label) do { \
		compat_stack_t __user *__uss = uss; \
		struct task_struct *t = current; \
		put_user_ex(ptr_to_compat((void __user *)t->sas_ss_sp), &__uss->ss_sp); \
		put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \
		put_user_ex(t->sas_ss_size, &__uss->ss_size); \
		unsafe_put_user(ptr_to_compat((void __user *)t->sas_ss_sp), \
		&__uss->ss_sp, label); \
		unsafe_put_user(t->sas_ss_flags, &__uss->ss_flags, label); \
		unsafe_put_user(t->sas_ss_size, &__uss->ss_size, label); \
		if (t->sas_ss_flags & SS_AUTODISARM) \
		sas_ss_reset(t); \
		} while (0);

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