From: Christophe Leroy christophe.leroy@csgroup.eu
commit 2c637d2df4ee4830e9d3eb2bd5412250522ce96e upstream.
low_sleep_handler() has an hardcoded restore of segment registers that doesn't take KUAP and KUEP into account.
Use head_32's load_segment_registers() routine instead.
Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection") Fixes: 31ed2b13c48d ("powerpc/32s: Implement Kernel Userspace Execution Prevention.") 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/21b05f7298c1b18f73e6e5b4cd5005aafa24b6da.159982010... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/kernel/head_32.S | 2 +- arch/powerpc/platforms/powermac/sleep.S | 9 +-------- 2 files changed, 2 insertions(+), 9 deletions(-)
--- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -1002,7 +1002,7 @@ BEGIN_MMU_FTR_SECTION END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS) blr
-load_segment_registers: +_GLOBAL(load_segment_registers) li r0, NUM_USER_SEGMENTS /* load up user segment register values */ mtctr r0 /* for context 0 */ li r3, 0 /* Kp = 0, Ks = 0, VSID = 0 */ --- a/arch/powerpc/platforms/powermac/sleep.S +++ b/arch/powerpc/platforms/powermac/sleep.S @@ -294,14 +294,7 @@ grackle_wake_up: * we do any r1 memory access as we are not sure they * are in a sane state above the first 256Mb region */ - li r0,16 /* load up segment register values */ - mtctr r0 /* for context 0 */ - lis r3,0x2000 /* Ku = 1, VSID = 0 */ - li r4,0 -3: mtsrin r3,r4 - addi r3,r3,0x111 /* increment VSID */ - addis r4,r4,0x1000 /* address of next segment */ - bdnz 3b + bl load_segment_registers sync isync