On 2/20/21 11:08 AM, kernel test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > master > head: f40ddce88593482919761f74910f42f4b84c004b > commit: 5a735583b764750726621b0396d03e4782911b77 arm/ftrace: Use > __patch_text() > date: 1 year, 3 months ago > config: arm-randconfig-r014-20210220 (attached as .config) > compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 > reproduce (this is a W=1 build): > wget > https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O > ~/bin/make.cross > chmod +x ~/bin/make.cross > # > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5a735583b764750726621b0396d03e4782911b77 > git remote add linus > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > git fetch --no-tags linus master > git checkout 5a735583b764750726621b0396d03e4782911b77 > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross > ARCH=arm > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <l...@intel.com> > > All errors (new ones prefixed by >>): > > arch/arm/kernel/patch.c: In function '__patch_text_real': >>> arch/arm/kernel/patch.c:94:11: error: implicit declaration of function >>> '__opcode_to_mem_thumb32' [-Werror=implicit-function-declaration] > 94 | insn = __opcode_to_mem_thumb32(insn); > | ^~~~~~~~~~~~~~~~~~~~~~~ > cc1: some warnings being treated as errors > > > vim +/__opcode_to_mem_thumb32 +94 arch/arm/kernel/patch.c > > ab0615e2d6fb07 Rabin Vincent 2014-04-24 55 > ab0615e2d6fb07 Rabin Vincent 2014-04-24 56 void __kprobes > __patch_text_real(void *addr, unsigned int insn, bool remap) > b21d55e98ac2bb Rabin Vincent 2012-02-18 57 { > b21d55e98ac2bb Rabin Vincent 2012-02-18 58 bool thumb2 = > IS_ENABLED(CONFIG_THUMB2_KERNEL); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 59 unsigned int uintaddr = > (uintptr_t) addr; > ab0615e2d6fb07 Rabin Vincent 2014-04-24 60 bool twopage = false; > ab0615e2d6fb07 Rabin Vincent 2014-04-24 61 unsigned long flags; > ab0615e2d6fb07 Rabin Vincent 2014-04-24 62 void *waddr = addr; > b21d55e98ac2bb Rabin Vincent 2012-02-18 63 int size; > b21d55e98ac2bb Rabin Vincent 2012-02-18 64 > ab0615e2d6fb07 Rabin Vincent 2014-04-24 65 if (remap) > ab0615e2d6fb07 Rabin Vincent 2014-04-24 66 waddr = > patch_map(addr, FIX_TEXT_POKE0, &flags); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 67 else > ab0615e2d6fb07 Rabin Vincent 2014-04-24 68 > __acquire(&patch_lock); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 69 > b21d55e98ac2bb Rabin Vincent 2012-02-18 70 if (thumb2 && > __opcode_is_thumb16(insn)) { > ab0615e2d6fb07 Rabin Vincent 2014-04-24 71 *(u16 *)waddr = > __opcode_to_mem_thumb16(insn); > b21d55e98ac2bb Rabin Vincent 2012-02-18 72 size = > sizeof(u16); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 73 } else if (thumb2 && > (uintaddr & 2)) { > b21d55e98ac2bb Rabin Vincent 2012-02-18 74 u16 first = > __opcode_thumb32_first(insn); > b21d55e98ac2bb Rabin Vincent 2012-02-18 75 u16 second = > __opcode_thumb32_second(insn); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 76 u16 *addrh0 = > waddr; > ab0615e2d6fb07 Rabin Vincent 2014-04-24 77 u16 *addrh1 = > waddr + 2; > ab0615e2d6fb07 Rabin Vincent 2014-04-24 78 > ab0615e2d6fb07 Rabin Vincent 2014-04-24 79 twopage = > (uintaddr & ~PAGE_MASK) == PAGE_SIZE - 2; > ab0615e2d6fb07 Rabin Vincent 2014-04-24 80 if (twopage && > remap) > ab0615e2d6fb07 Rabin Vincent 2014-04-24 81 addrh1 > = patch_map(addr + 2, FIX_TEXT_POKE1, NULL); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 82 > ab0615e2d6fb07 Rabin Vincent 2014-04-24 83 *addrh0 = > __opcode_to_mem_thumb16(first); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 84 *addrh1 = > __opcode_to_mem_thumb16(second); > b21d55e98ac2bb Rabin Vincent 2012-02-18 85 > ab0615e2d6fb07 Rabin Vincent 2014-04-24 86 if (twopage && > addrh1 != addr + 2) { > ab0615e2d6fb07 Rabin Vincent 2014-04-24 87 > flush_kernel_vmap_range(addrh1, 2); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 88 > patch_unmap(FIX_TEXT_POKE1, NULL); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 89 } > b21d55e98ac2bb Rabin Vincent 2012-02-18 90 > b21d55e98ac2bb Rabin Vincent 2012-02-18 91 size = > sizeof(u32); > b21d55e98ac2bb Rabin Vincent 2012-02-18 92 } else { > b21d55e98ac2bb Rabin Vincent 2012-02-18 93 if (thumb2) > b21d55e98ac2bb Rabin Vincent 2012-02-18 @94 insn = > __opcode_to_mem_thumb32(insn); > b21d55e98ac2bb Rabin Vincent 2012-02-18 95 else > b21d55e98ac2bb Rabin Vincent 2012-02-18 96 insn = > __opcode_to_mem_arm(insn); > b21d55e98ac2bb Rabin Vincent 2012-02-18 97 > ab0615e2d6fb07 Rabin Vincent 2014-04-24 98 *(u32 *)waddr = > insn; > b21d55e98ac2bb Rabin Vincent 2012-02-18 99 size = > sizeof(u32); > b21d55e98ac2bb Rabin Vincent 2012-02-18 100 } > b21d55e98ac2bb Rabin Vincent 2012-02-18 101 > ab0615e2d6fb07 Rabin Vincent 2014-04-24 102 if (waddr != addr) { > ab0615e2d6fb07 Rabin Vincent 2014-04-24 103 > flush_kernel_vmap_range(waddr, twopage ? size / 2 : size); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 104 > patch_unmap(FIX_TEXT_POKE0, &flags); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 105 } else > ab0615e2d6fb07 Rabin Vincent 2014-04-24 106 > __release(&patch_lock); > ab0615e2d6fb07 Rabin Vincent 2014-04-24 107 > b21d55e98ac2bb Rabin Vincent 2012-02-18 108 > flush_icache_range((uintptr_t)(addr), > b21d55e98ac2bb Rabin Vincent 2012-02-18 109 > (uintptr_t)(addr) + size); > b21d55e98ac2bb Rabin Vincent 2012-02-18 110 } > b21d55e98ac2bb Rabin Vincent 2012-02-18 111 > > :::::: The code at line 94 was first introduced by commit > :::::: b21d55e98ac2bbcbbeec9a8cb091f717fd95b072 ARM: 7332/1: extract out code > patch function from kprobes > > :::::: TO: Rabin Vincent <ra...@rab.in> > :::::: CC: Russell King <rmk+ker...@arm.linux.org.uk>
This comes down to: CONFIG_ARM_THUMB=y CONFIG_CPU_BIG_ENDIAN=y CONFIG_CPU_ENDIAN_BE32=y and <asm/opcodes.h>, where arch/arm/asm/opcodes.h says: /* * On BE32 systems, using 32-bit accesses to store Thumb instructions will not * work in all cases, due to alignment constraints. For now, a correct * version is not provided for BE32. */ Should we try to find a way to prevent this combination from happening? -- ~Randy
