dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

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: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Paul Mackerras 2005-12-20 15:38:47 +11:00
parent 7116317dc9
commit 3eb6f26bcd
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/powerpc/kernel/entry_64.S
View File

@ -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