From 52247123749cc3cbc30168b33ad8c69515c96d23 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Sun, 27 Jul 2014 07:23:41 +0400 Subject: xtensa: fix access to THREAD_RA/THREAD_SP/THREAD_DS With SMP and a lot of debug options enabled task_struct::thread gets out of reach of s32i/l32i instructions with base pointing at task_struct, breaking build with the following messages: arch/xtensa/kernel/entry.S: Assembler messages: arch/xtensa/kernel/entry.S:1002: Error: operand 3 of 'l32i.n' has invalid value '1048' arch/xtensa/kernel/entry.S:1831: Error: operand 3 of 's32i.n' has invalid value '1040' arch/xtensa/kernel/entry.S:1832: Error: operand 3 of 's32i.n' has invalid value '1044' Change base to point to task_struct::thread in such cases. Don't use a10 in _switch_to to save/restore prev pointer as a2 is not clobbered. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov --- arch/xtensa/kernel/entry.S | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'arch/xtensa/kernel/entry.S') diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index ef7f4990722b..db96acb1362b 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -1820,7 +1820,6 @@ ENTRY(_switch_to) entry a1, 16 - mov a10, a2 # preserve 'prev' (a2) mov a11, a3 # and 'next' (a3) l32i a4, a2, TASK_THREAD_INFO @@ -1828,8 +1827,14 @@ ENTRY(_switch_to) save_xtregs_user a4 a6 a8 a9 a12 a13 THREAD_XTREGS_USER - s32i a0, a10, THREAD_RA # save return address - s32i a1, a10, THREAD_SP # save stack pointer +#if THREAD_RA > 1020 || THREAD_SP > 1020 + addi a10, a2, TASK_THREAD + s32i a0, a10, THREAD_RA - TASK_THREAD # save return address + s32i a1, a10, THREAD_SP - TASK_THREAD # save stack pointer +#else + s32i a0, a2, THREAD_RA # save return address + s32i a1, a2, THREAD_SP # save stack pointer +#endif /* Disable ints while we manipulate the stack pointer. */ @@ -1870,7 +1875,6 @@ ENTRY(_switch_to) load_xtregs_user a5 a6 a8 a9 a12 a13 THREAD_XTREGS_USER wsr a14, ps - mov a2, a10 # return 'prev' rsync retw -- cgit v1.2.3 From 7128039fe2dd3d59da9e4ffa036f3aaa3ba87b9f Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Mon, 21 Jul 2014 22:01:51 +0400 Subject: xtensa: fix TLBTEMP_BASE_2 region handling in fast_second_level_miss Current definition of TLBTEMP_BASE_2 is always 32K above the TLBTEMP_BASE_1, whereas fast_second_level_miss handler for the TLBTEMP region analyzes virtual address bit (PAGE_SHIFT + DCACHE_ALIAS_ORDER) to determine TLBTEMP region where the fault happened. The size of the TLBTEMP region is also checked incorrectly: not 64K, but twice data cache way size (whicht may as well be less than the instruction cache way size). Fix TLBTEMP_BASE_2 to be TLBTEMP_BASE_1 + data cache way size. Provide TLBTEMP_SIZE that is a greater of doubled data cache way size or the instruction cache way size, and use it to determine if the second level TLB miss occured in the TLBTEMP region. Practical occurence of page faults in the TLBTEMP area is extremely rare, this code can be tested by deletion of all w[di]tlb instructions in the tlbtemp_mapping region. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov --- arch/xtensa/kernel/entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/xtensa/kernel/entry.S') diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index db96acb1362b..21917e5fd53a 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -1565,7 +1565,7 @@ ENTRY(fast_second_level_miss) rsr a0, excvaddr bltu a0, a3, 2f - addi a1, a0, -(2 << (DCACHE_ALIAS_ORDER + PAGE_SHIFT)) + addi a1, a0, -TLBTEMP_SIZE bgeu a1, a3, 2f /* Check if we have to restore an ITLB mapping. */ -- cgit v1.2.3 From d1b6ba82a50cecf94be540a3a153aa89d97511a0 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Thu, 31 Jul 2014 22:40:57 +0400 Subject: xtensa: fix a6 and a7 handling in fast_syscall_xtensa Remove restoring a6 on some return paths and instead modify and restore it in a single place, using symbolic name. Correctly restore a7 from PT_AREG7 in case of illegal a6 value. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov --- arch/xtensa/kernel/entry.S | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) (limited to 'arch/xtensa/kernel/entry.S') diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 21917e5fd53a..a06b7efaae82 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -1001,9 +1001,8 @@ ENTRY(fast_syscall_xtensa) movi a7, 4 # sizeof(unsigned int) access_ok a3, a7, a0, a2, .Leac # a0: scratch reg, a2: sp - addi a6, a6, -1 # assuming SYS_XTENSA_ATOMIC_SET = 1 - _bgeui a6, SYS_XTENSA_COUNT - 1, .Lill - _bnei a6, SYS_XTENSA_ATOMIC_CMP_SWP - 1, .Lnswp + _bgeui a6, SYS_XTENSA_COUNT, .Lill + _bnei a6, SYS_XTENSA_ATOMIC_CMP_SWP, .Lnswp /* Fall through for ATOMIC_CMP_SWP. */ @@ -1015,27 +1014,26 @@ TRY s32i a5, a3, 0 # different, modify value l32i a7, a2, PT_AREG7 # restore a7 l32i a0, a2, PT_AREG0 # restore a0 movi a2, 1 # and return 1 - addi a6, a6, 1 # restore a6 (really necessary?) rfe 1: l32i a7, a2, PT_AREG7 # restore a7 l32i a0, a2, PT_AREG0 # restore a0 movi a2, 0 # return 0 (note that we cannot set - addi a6, a6, 1 # restore a6 (really necessary?) rfe .Lnswp: /* Atomic set, add, and exg_add. */ TRY l32i a7, a3, 0 # orig + addi a6, a6, -SYS_XTENSA_ATOMIC_SET add a0, a4, a7 # + arg moveqz a0, a4, a6 # set + addi a6, a6, SYS_XTENSA_ATOMIC_SET TRY s32i a0, a3, 0 # write new value mov a0, a2 mov a2, a7 l32i a7, a0, PT_AREG7 # restore a7 l32i a0, a0, PT_AREG0 # restore a0 - addi a6, a6, 1 # restore a6 (really necessary?) rfe CATCH @@ -1044,7 +1042,7 @@ CATCH movi a2, -EFAULT rfe -.Lill: l32i a7, a2, PT_AREG0 # restore a7 +.Lill: l32i a7, a2, PT_AREG7 # restore a7 l32i a0, a2, PT_AREG0 # restore a0 movi a2, -EINVAL rfe -- cgit v1.2.3 From 9184289c979e78ce466993b53fc951633441e571 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Thu, 7 Aug 2014 03:32:30 +0400 Subject: xtensa: deprecate fast_xtensa and fast_spill_registers syscalls These syscalls are not used by userspace tools for some time now, and they have issues when called with invalid arguments. It's not worth changing signal delivery mechanism as we don't expect any new users for these syscalls. Let's keep them for backwards compatibility under #ifdef, disabled by default. Signed-off-by: Max Filippov --- arch/xtensa/kernel/entry.S | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'arch/xtensa/kernel/entry.S') diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index a06b7efaae82..82bbfa5a05b3 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -986,6 +986,8 @@ ENDPROC(fast_syscall_unrecoverable) * j done */ +#ifdef CONFIG_FAST_SYSCALL_XTENSA + #define TRY \ .section __ex_table, "a"; \ .word 66f, 67f; \ @@ -1049,6 +1051,18 @@ CATCH ENDPROC(fast_syscall_xtensa) +#else /* CONFIG_FAST_SYSCALL_XTENSA */ + +ENTRY(fast_syscall_xtensa) + + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, -ENOSYS + rfe + +ENDPROC(fast_syscall_xtensa) + +#endif /* CONFIG_FAST_SYSCALL_XTENSA */ + /* fast_syscall_spill_registers. * @@ -1064,6 +1078,8 @@ ENDPROC(fast_syscall_xtensa) * Note: We assume the stack pointer is EXC_TABLE_KSTK in the fixup handler. */ +#ifdef CONFIG_FAST_SYSCALL_SPILL_REGISTERS + ENTRY(fast_syscall_spill_registers) /* Register a FIXUP handler (pass current wb as a parameter) */ @@ -1398,6 +1414,18 @@ ENTRY(fast_syscall_spill_registers_fixup_return) ENDPROC(fast_syscall_spill_registers_fixup_return) +#else /* CONFIG_FAST_SYSCALL_SPILL_REGISTERS */ + +ENTRY(fast_syscall_spill_registers) + + l32i a0, a2, PT_AREG0 # restore a0 + movi a2, -ENOSYS + rfe + +ENDPROC(fast_syscall_spill_registers) + +#endif /* CONFIG_FAST_SYSCALL_SPILL_REGISTERS */ + #ifdef CONFIG_MMU /* * We should never get here. Bail out! -- cgit v1.2.3