The commit 38fd94b0 'arm64: Work around Falkor erratum 1003' has been added to fix the hardware bug but causing a system crash. The value of the register x1 which contains 'struct mm_struct *' should be preserved inside macro pre_ttbr0_update_workaround.
Macro pre_ttbr0_update_workaround expects 2nd and 3rd arguments are temporary registers. Don't clobber register x1, Otherwise the next load operation 'mmid x1 x1' access the invalid address. [<ffff0000080989a0>] cpu_do_switch_mm+0x20/0x40 [<ffff000008b18614>] efi_virtmap_load+0x34/0x40 [<ffff000008b1812c>] virt_efi_get_next_variable+0x64/0xc8 [<ffff000008b16204>] efivar_init+0x8c/0x348 [<ffff0000092b777c>] efisubsys_init+0xd4/0x270 [<ffff000009270c74>] do_one_initcall+0x80/0x110 [<ffff000009270ea0>] kernel_init_freeable+0x19c/0x240 [<ffff000008d8cef0>] kernel_init+0x10/0x100 [<ffff000008082ec0>] ret_from_fork+0x10/0x50 Code: d5033fdf b340bc01 d5182001 d5033fdf (f9416821) ---[ end trace 15247ca922eb6bb7 ]--- note: swapper/0[1] exited with preempt_count 2 Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b SMP: stopping secondary CPUs ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Signed-off-by: Shanker Donthineni <shank...@codeaurora.org> --- arch/arm64/mm/proc.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index cd4d53d..877d42f 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -138,7 +138,7 @@ ENDPROC(cpu_do_resume) * - pgd_phys - physical address of new TTB */ ENTRY(cpu_do_switch_mm) - pre_ttbr0_update_workaround x0, x1, x2 + pre_ttbr0_update_workaround x0, x2, x3 mmid x1, x1 // get mm->context.id bfi x0, x1, #48, #16 // set the ASID msr ttbr0_el1, x0 // set TTBR0 -- Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.