powerpc/64e: Fix early TLB miss with KUAP
With KUAP, the TLB miss handler bails out when an access to user memory is performed with a nul TID. But the normal TLB miss routine which is only used early during boot does the check regardless for all memory areas, not only user memory. By chance there is no early IO or vmalloc access, but when KASAN come we will start having early TLB misses. Fix it by creating a special branch for user accesses similar to the one in the 'bolted' TLB miss handlers. Unfortunately SPRN_MAS1 is now read too early and there are no registers available to preserve it so it will be read a second time. Fixes: 57bc9638 ("powerpc/kuap: Wire-up KUAP on book3e/64") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8d6c5859a45935d6e1a336da4dc20be421e8cea7.1656427701.git.christophe.leroy@csgroup.eu
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