Lichao Liu 2984b3f8c2 MIPS: Loongson-2EF: disable fix-loongson3-llsc in compiler ... Firstly, Loongson-2EF support ll/sc instructions, but doesn't need fix-loongson3-llsc compile option. Secondly, fix-loongson3-llsc will cause kernel startup fail at futex_init, because compiler will add 'sync' before 'll', which will affect __ex_table. futex_init will pass NULL uaddr parameter to futex_atomic_cmpxchg_inatomic. futex_atomic_cmpxchg_inatomic will access uaddr directly, which will cause page fault exception, the exception should be handled by __ex_table's nextinsn if the exception insn exsit in __ex_table. Because __ex_table is affected by compiler, the exception can not be handled, and futex_atomic_cmpxchg_inatomic will crash. Error code as below: __ex_table.insn = 1b, which is 'sync' compiled with fix-loongson3-llsc, but the actual exception instrction is ll. So, do_page_fault will not find the correct inst in __ex_table, and can not handle this exception. "1: "user_ll("%1", "%3")" \n" " bne %1, %z4, 3f \n" " .set pop \n" " move $1, %z5 \n" " .set "MIPS_ISA_ARCH_LEVEL" \n" "2: "user_sc("$1", "%2")" \n" " beqz $1, 1b \n" "3: " __SYNC_ELSE(full, loongson3_war, __WEAK_LLSC_MB) "\n" " .insn \n" " .set pop \n" " .section .fixup,\"ax\" \n" "4: li %0, %6 \n" " j 3b \n" " .previous \n" " .section __ex_table,\"a\" \n" " "__UA_ADDR "\t1b, 4b \n" " "__UA_ADDR "\t2b, 4b \n" " .previous Signed-off-by: Lichao Liu <liulichao@loongson.cn> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>		2020-06-22 17:35:31 +02:00
..
common	MIPS: Fix exception handler memcpy()	2020-05-24 09:15:54 +02:00
fuloong-2e	MIPS: Replace setup_irq() by request_irq()	2020-03-05 16:47:35 +01:00
lemote-2f	mips: loongsoon2ef: remove private clk api	2020-04-16 17:34:23 +02:00
Kconfig	mips: loongsoon2ef: remove private clk api	2020-04-16 17:34:23 +02:00
Makefile
Platform	MIPS: Loongson-2EF: disable fix-loongson3-llsc in compiler	2020-06-22 17:35:31 +02:00