5.15-stable review patch. If anyone has any objections, please let me know.
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From: Al Viro viro@zeniv.linux.org.uk
commit 1f36cd05e0081f2c75769a551d584c4ffb2a5660 upstream.
Fault handler used to make non-trivial calls, so it needed to set a stack frame up. Used to be save ... - grab a stack frame, old %o... become %i... .... ret - go back to address originally in %o7, currently %i7 restore - switch to previous stack frame, in delay slot Non-trivial calls had been gone since ab5e8b331244 and that code should have become retl - go back to address in %o7 clr %o0 - have return value set to 0 What it had become instead was ret - go back to address in %i7 - return address of *caller* clr %o0 - have return value set to 0 which is not good, to put it mildly - we forcibly return 0 from csum_and_copy_{from,to}_iter() (which is what the call of that thing had been inlined into) and do that without dropping the stack frame of said csum_and_copy_..._iter(). Confuses the hell out of the caller of csum_and_copy_..._iter(), obviously...
Reviewed-by: Sam Ravnborg sam@ravnborg.org Fixes: ab5e8b331244 "sparc32: propagate the calling conventions change down to __csum_partial_copy_sparc_generic()" Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/sparc/lib/checksum_32.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/sparc/lib/checksum_32.S +++ b/arch/sparc/lib/checksum_32.S @@ -453,5 +453,5 @@ ccslow: cmp %g1, 0 * we only bother with faults on loads... */
cc_fault: - ret + retl clr %o0