5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jan Beulich jbeulich@suse.com
commit 5c4e79e29a9fe4ea132118ac40c2bc97cfe23077 upstream.
The interface specifies the symnum field as an input and output; the hypervisor sets it to the next sequential symbol's index. xensyms_next() incrementing the position explicitly (and xensyms_next_sym() decrementing it to "rewind") is only correct as long as the sequence of symbol indexes is non-sparse. Use the hypervisor-supplied value instead to update the position in xensyms_next(), and use the saved incoming index in xensyms_next_sym().
Cc: stable@kernel.org Fixes: a11f4f0a4e18 ("xen: xensyms support") Signed-off-by: Jan Beulich jbeulich@suse.com Reviewed-by: Juergen Gross jgross@suse.com Message-ID: 15d5e7fa-ec5d-422f-9319-d28bed916349@suse.com Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/xen/xenfs/xensyms.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/xen/xenfs/xensyms.c +++ b/drivers/xen/xenfs/xensyms.c @@ -48,7 +48,7 @@ static int xensyms_next_sym(struct xensy return -ENOMEM;
set_xen_guest_handle(symdata->name, xs->name); - symdata->symnum--; /* Rewind */ + symdata->symnum = symnum; /* Rewind */
ret = HYPERVISOR_platform_op(&xs->op); if (ret < 0) @@ -78,7 +78,7 @@ static void *xensyms_next(struct seq_fil { struct xensyms *xs = (struct xensyms *)m->private;
- xs->op.u.symdata.symnum = ++(*pos); + *pos = xs->op.u.symdata.symnum;
if (xensyms_next_sym(xs)) return NULL;