x86/uaccess, xen: Suppress SMAP warnings (4fc0f0e9) · Commits · 戴 / test

drivers/xen/privcmd.o: warning: objtool: privcmd_ioctl()+0x1414: call to hypercall_page() with UACCESS enabled Some Xen hypercalls allow parameter buffers in user land, so they need to set AC=1. Avoid the warning for those cases. Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by:

Juergen Gross <jgross@suse.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: andrew.cooper3@citrix.com Signed-off-by:

Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/xen/hypercall.h

+20 −4

Original line number	Diff line number	Diff line
		@@ -214,6 +214,22 @@ xen_single_call(unsigned int call,
		return (long)__res;
		}

		static __always_inline void __xen_stac(void)
		{
		/*
		* Suppress objtool seeing the STAC/CLAC and getting confused about it
		* calling random code with AC=1.
		*/
		asm volatile(ANNOTATE_IGNORE_ALTERNATIVE
		ASM_STAC ::: "memory", "flags");
		}

		static __always_inline void __xen_clac(void)
		{
		asm volatile(ANNOTATE_IGNORE_ALTERNATIVE
		ASM_CLAC ::: "memory", "flags");
		}

		static inline long
		privcmd_call(unsigned int call,
		unsigned long a1, unsigned long a2,
		@@ -222,9 +238,9 @@ privcmd_call(unsigned int call,
		{
		long res;

		stac();
		__xen_stac();
		res = xen_single_call(call, a1, a2, a3, a4, a5);
		clac();
		__xen_clac();

		return res;
		}
		@@ -421,9 +437,9 @@ HYPERVISOR_dm_op(
		domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
		{
		int ret;
		stac();
		__xen_stac();
		ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs);
		clac();
		__xen_clac();
		return ret;
		}

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