From d7bd7a8ae8cdb3f1414b1e032759d9ef324eb040 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Wed, 15 Jul 2009 17:41:36 -0700 Subject: Secure AVX changes for auditing code. The original AVX patch used a function pointer to handle the difference between machines with and without AVX support. This is insecure. A well-placed memory exploit could lead to redirection of the execution. Using a variable and several tests is a bit slower but cannot be exploited in this way. --- sysdeps/x86_64/dl-trampoline.h | 291 ----------------------------------------- 1 file changed, 291 deletions(-) delete mode 100644 sysdeps/x86_64/dl-trampoline.h (limited to 'sysdeps/x86_64/dl-trampoline.h') diff --git a/sysdeps/x86_64/dl-trampoline.h b/sysdeps/x86_64/dl-trampoline.h deleted file mode 100644 index d63b7d03c4..0000000000 --- a/sysdeps/x86_64/dl-trampoline.h +++ /dev/null @@ -1,291 +0,0 @@ -/* Partial PLT profile trampoline to save and restore x86-64 vector - registers. - Copyright (C) 2009 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA - 02111-1307 USA. */ - - leaq 48(%rbx), %rax - movq %rax, LR_RSP_OFFSET(%rsp) - - /* This is to provide backward binary compatility for existing - audit modules. */ - MOVXMM %xmm0, (LR_XMM_OFFSET)(%rsp) - MOVXMM %xmm1, (LR_XMM_OFFSET + XMM_SIZE)(%rsp) - MOVXMM %xmm2, (LR_XMM_OFFSET + XMM_SIZE*2)(%rsp) - MOVXMM %xmm3, (LR_XMM_OFFSET + XMM_SIZE*3)(%rsp) - MOVXMM %xmm4, (LR_XMM_OFFSET + XMM_SIZE*4)(%rsp) - MOVXMM %xmm5, (LR_XMM_OFFSET + XMM_SIZE*5)(%rsp) - MOVXMM %xmm6, (LR_XMM_OFFSET + XMM_SIZE*6)(%rsp) - MOVXMM %xmm7, (LR_XMM_OFFSET + XMM_SIZE*7)(%rsp) - -#ifdef RESTORE_AVX - /* This is to support AVX audit modules. */ - vmovdqu %ymm0, (LR_VECTOR_OFFSET)(%rsp) - vmovdqu %ymm1, (LR_VECTOR_OFFSET + VECTOR_SIZE)(%rsp) - vmovdqu %ymm2, (LR_VECTOR_OFFSET + VECTOR_SIZE*2)(%rsp) - vmovdqu %ymm3, (LR_VECTOR_OFFSET + VECTOR_SIZE*3)(%rsp) - vmovdqu %ymm4, (LR_VECTOR_OFFSET + VECTOR_SIZE*4)(%rsp) - vmovdqu %ymm5, (LR_VECTOR_OFFSET + VECTOR_SIZE*5)(%rsp) - vmovdqu %ymm6, (LR_VECTOR_OFFSET + VECTOR_SIZE*6)(%rsp) - vmovdqu %ymm7, (LR_VECTOR_OFFSET + VECTOR_SIZE*7)(%rsp) - - /* Save xmm0-xmm7 registers to detect if any of them are - changed by audit module. */ - vmovdqa %xmm0, (LR_SIZE)(%rsp) - vmovdqa %xmm1, (LR_SIZE + XMM_SIZE)(%rsp) - vmovdqa %xmm2, (LR_SIZE + XMM_SIZE*2)(%rsp) - vmovdqa %xmm3, (LR_SIZE + XMM_SIZE*3)(%rsp) - vmovdqa %xmm4, (LR_SIZE + XMM_SIZE*4)(%rsp) - vmovdqa %xmm5, (LR_SIZE + XMM_SIZE*5)(%rsp) - vmovdqa %xmm6, (LR_SIZE + XMM_SIZE*6)(%rsp) - vmovdqa %xmm7, (LR_SIZE + XMM_SIZE*7)(%rsp) -#endif - - movq %rsp, %rcx # La_x86_64_regs pointer to %rcx. - movq 48(%rbx), %rdx # Load return address if needed. - movq 40(%rbx), %rsi # Copy args pushed by PLT in register. - movq 32(%rbx), %rdi # %rdi: link_map, %rsi: reloc_index - leaq 16(%rbx), %r8 - call _dl_profile_fixup # Call resolver. - - movq %rax, %r11 # Save return value. - - movq 8(%rbx), %rax # Get back register content. - movq LR_RDX_OFFSET(%rsp), %rdx - movq LR_R8_OFFSET(%rsp), %r8 - movq LR_R9_OFFSET(%rsp), %r9 - -#ifdef RESTORE_AVX - /* Check if any xmm0-xmm7 registers are changed by audit - module. */ - vmovdqa (LR_XMM_OFFSET)(%rsp), %xmm0 - vpcmpeqq (LR_SIZE)(%rsp), %xmm0, %xmm1 - vpmovmskb %xmm1, %esi - cmpl $0xffff, %esi - jne 1f - - vmovdqa (LR_XMM_OFFSET + XMM_SIZE)(%rsp), %xmm0 - vpcmpeqq (LR_SIZE + XMM_SIZE)(%rsp), %xmm0, %xmm1 - vpmovmskb %xmm1, %esi - cmpl $0xffff, %esi - jne 1f - - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*2)(%rsp), %xmm0 - vpcmpeqq (LR_SIZE + XMM_SIZE*2)(%rsp), %xmm0, %xmm1 - vpmovmskb %xmm1, %esi - cmpl $0xffff, %esi - jne 1f - - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*3)(%rsp), %xmm0 - vpcmpeqq (LR_SIZE + XMM_SIZE*3)(%rsp), %xmm0, %xmm1 - vpmovmskb %xmm1, %esi - cmpl $0xffff, %esi - jne 1f - - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*4)(%rsp), %xmm0 - vpcmpeqq (LR_SIZE + XMM_SIZE*4)(%rsp), %xmm0, %xmm1 - vpmovmskb %xmm1, %esi - cmpl $0xffff, %esi - jne 1f - - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*5)(%rsp), %xmm0 - vpcmpeqq (LR_SIZE + XMM_SIZE*5)(%rsp), %xmm0, %xmm1 - vpmovmskb %xmm1, %esi - cmpl $0xffff, %esi - jne 1f - - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*6)(%rsp), %xmm0 - vpcmpeqq (LR_SIZE + XMM_SIZE*6)(%rsp), %xmm0, %xmm1 - vpmovmskb %xmm1, %esi - cmpl $0xffff, %esi - jne 1f - - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*7)(%rsp), %xmm0 - vpcmpeqq (LR_SIZE + XMM_SIZE*7)(%rsp), %xmm0, %xmm1 - vpmovmskb %xmm1, %esi - cmpl $0xffff, %esi - jne 1f - - /* We restore AVX registers only if xmm0-xmm7 registers are - unchanged. */ - vmovdqu (LR_VECTOR_OFFSET)(%rsp), %ymm0 - vmovdqu (LR_VECTOR_OFFSET + VECTOR_SIZE)(%rsp), %ymm1 - vmovdqu (LR_VECTOR_OFFSET + VECTOR_SIZE*2)(%rsp), %ymm2 - vmovdqu (LR_VECTOR_OFFSET + VECTOR_SIZE*3)(%rsp), %ymm3 - vmovdqu (LR_VECTOR_OFFSET + VECTOR_SIZE*4)(%rsp), %ymm4 - vmovdqu (LR_VECTOR_OFFSET + VECTOR_SIZE*5)(%rsp), %ymm5 - vmovdqu (LR_VECTOR_OFFSET + VECTOR_SIZE*6)(%rsp), %ymm6 - vmovdqu (LR_VECTOR_OFFSET + VECTOR_SIZE*7)(%rsp), %ymm7 - jmp 2f - -1: - vmovdqa (LR_XMM_OFFSET)(%rsp), %xmm0 - vmovdqa (LR_XMM_OFFSET + XMM_SIZE)(%rsp), %xmm1 - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*2)(%rsp), %xmm2 - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*3)(%rsp), %xmm3 - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*4)(%rsp), %xmm4 - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*5)(%rsp), %xmm5 - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*6)(%rsp), %xmm6 - vmovdqa (LR_XMM_OFFSET + XMM_SIZE*7)(%rsp), %xmm7 - -2: -#else - movaps (LR_XMM_OFFSET)(%rsp), %xmm0 - movaps (LR_XMM_OFFSET + XMM_SIZE)(%rsp), %xmm1 - movaps (LR_XMM_OFFSET + XMM_SIZE*2)(%rsp), %xmm2 - movaps (LR_XMM_OFFSET + XMM_SIZE*3)(%rsp), %xmm3 - movaps (LR_XMM_OFFSET + XMM_SIZE*4)(%rsp), %xmm4 - movaps (LR_XMM_OFFSET + XMM_SIZE*5)(%rsp), %xmm5 - movaps (LR_XMM_OFFSET + XMM_SIZE*6)(%rsp), %xmm6 - movaps (LR_XMM_OFFSET + XMM_SIZE*7)(%rsp), %xmm7 -#endif - - movq 16(%rbx), %r10 # Anything in framesize? - testq %r10, %r10 - jns 3f - - /* There's nothing in the frame size, so there - will be no call to the _dl_call_pltexit. */ - - /* Get back registers content. */ - movq LR_RCX_OFFSET(%rsp), %rcx - movq LR_RSI_OFFSET(%rsp), %rsi - movq LR_RDI_OFFSET(%rsp), %rdi - - movq %rbx, %rsp - movq (%rsp), %rbx - cfi_restore(rbx) - cfi_def_cfa_register(%rsp) - - addq $48, %rsp # Adjust the stack to the return value - # (eats the reloc index and link_map) - cfi_adjust_cfa_offset(-48) - jmp *%r11 # Jump to function address. - -3: - cfi_adjust_cfa_offset(48) - cfi_rel_offset(%rbx, 0) - cfi_def_cfa_register(%rbx) - - /* At this point we need to prepare new stack for the function - which has to be called. We copy the original stack to a - temporary buffer of the size specified by the 'framesize' - returned from _dl_profile_fixup */ - - leaq LR_RSP_OFFSET(%rbx), %rsi # stack - addq $8, %r10 - andq $0xfffffffffffffff0, %r10 - movq %r10, %rcx - subq %r10, %rsp - movq %rsp, %rdi - shrq $3, %rcx - rep - movsq - - movq 24(%rdi), %rcx # Get back register content. - movq 32(%rdi), %rsi - movq 40(%rdi), %rdi - - call *%r11 - - mov 24(%rbx), %rsp # Drop the copied stack content - - /* Now we have to prepare the La_x86_64_retval structure for the - _dl_call_pltexit. The La_x86_64_regs is being pointed by rsp now, - so we just need to allocate the sizeof(La_x86_64_retval) space on - the stack, since the alignment has already been taken care of. */ -#ifdef RESTORE_AVX - /* sizeof(La_x86_64_retval). Need extra space for 2 SSE - registers to detect if xmm0/xmm1 registers are changed - by audit module. */ - subq $(LRV_SIZE + XMM_SIZE*2), %rsp -#else - subq $LRV_SIZE, %rsp # sizeof(La_x86_64_retval) -#endif - movq %rsp, %rcx # La_x86_64_retval argument to %rcx. - - /* Fill in the La_x86_64_retval structure. */ - movq %rax, LRV_RAX_OFFSET(%rcx) - movq %rdx, LRV_RDX_OFFSET(%rcx) - - MOVXMM %xmm0, LRV_XMM0_OFFSET(%rcx) - MOVXMM %xmm1, LRV_XMM1_OFFSET(%rcx) - -#ifdef RESTORE_AVX - /* This is to support AVX audit modules. */ - vmovdqu %ymm0, LRV_VECTOR0_OFFSET(%rcx) - vmovdqu %ymm1, LRV_VECTOR1_OFFSET(%rcx) - - /* Save xmm0/xmm1 registers to detect if they are changed - by audit module. */ - vmovdqa %xmm0, (LRV_SIZE)(%rcx) - vmovdqa %xmm1, (LRV_SIZE + XMM_SIZE)(%rcx) -#endif - - fstpt LRV_ST0_OFFSET(%rcx) - fstpt LRV_ST1_OFFSET(%rcx) - - movq 24(%rbx), %rdx # La_x86_64_regs argument to %rdx. - movq 40(%rbx), %rsi # Copy args pushed by PLT in register. - movq 32(%rbx), %rdi # %rdi: link_map, %rsi: reloc_index - call _dl_call_pltexit - - /* Restore return registers. */ - movq LRV_RAX_OFFSET(%rsp), %rax - movq LRV_RDX_OFFSET(%rsp), %rdx - -#ifdef RESTORE_AVX - /* Check if xmm0/xmm1 registers are changed by audit module. */ - vmovdqa LRV_XMM0_OFFSET(%rsp), %xmm0 - vpcmpeqq (LRV_SIZE)(%rsp), %xmm0, %xmm1 - vpmovmskb %xmm1, %esi - cmpl $0xffff, %esi - jne 4f - - /* We restore AVX registers only if xmm0/xmm1 registers are - unchanged. */ - vmovdqa LRV_XMM1_OFFSET(%rsp), %xmm0 - vpcmpeqq (LRV_SIZE + XMM_SIZE)(%rsp), %xmm0, %xmm1 - vpmovmskb %xmm1, %esi - cmpl $0xffff, %esi - jne 4f - - vmovdqu LRV_VECTOR0_OFFSET(%rsp), %ymm0 - vmovdqu LRV_VECTOR1_OFFSET(%rsp), %ymm1 - jmp 5f - -4: - vmovdqa LRV_XMM0_OFFSET(%rsp), %xmm0 - vmovdqa LRV_XMM1_OFFSET(%rsp), %xmm1 -5: -#else - movaps LRV_XMM0_OFFSET(%rsp), %xmm0 - movaps LRV_XMM1_OFFSET(%rsp), %xmm1 -#endif - - fldt LRV_ST0_OFFSET(%rsp) - fldt LRV_ST0_OFFSET(%rsp) - - movq %rbx, %rsp - movq (%rsp), %rbx - cfi_restore(rbx) - cfi_def_cfa_register(%rsp) - - addq $48, %rsp # Adjust the stack to the return value - # (eats the reloc index and link_map) - cfi_adjust_cfa_offset(-48) - retq -- cgit 1.4.1