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Commit 3eb6f26b authored by Paul Mackerras's avatar Paul Mackerras
Browse files

powerpc: correct register usage in 64-bit syscall exit path 



Since we don't restore the volatile registers in the syscall exit
path, we need to make sure we don't leak any potentially interesting
values from the kernel to userspace.  This was already the case for
all except r11.  This makes it use r11 for an MSR value, so r11 will
have an (uninteresting) MSR value in it on return to userspace.

Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 7116317d

arch/powerpc/kernel/entry_64.S

+2 −2
Original line number Diff line number Diff line
@@ -183,8 +183,8 @@ syscall_exit_trace_cont: 
	ld	r13,GPR13(r1)		/* returning to usermode */

1:	ld	r2,GPR2(r1)

	li	r12,MSR_RI

	andc	r10,r10,r12

	mtmsrd	r10,1			/* clear MSR.RI */

	andc	r11,r10,r12

	mtmsrd	r11,1			/* clear MSR.RI */

	ld	r1,GPR1(r1)

	mtlr	r4

	mtcr	r5