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Diffstat (limited to 'sysdeps/arm/nacl/dl-trampoline.S')
| -rw-r--r-- | sysdeps/arm/nacl/dl-trampoline.S | 278 |
1 files changed, 0 insertions, 278 deletions
diff --git a/sysdeps/arm/nacl/dl-trampoline.S b/sysdeps/arm/nacl/dl-trampoline.S deleted file mode 100644 index 9486d7e..0000000 --- a/sysdeps/arm/nacl/dl-trampoline.S +++ /dev/null @@ -1,278 +0,0 @@ -/* PLT trampolines. ARM/NaCl version. - Copyright (C) 2015-2017 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, see - <http://www.gnu.org/licenses/>. */ - -#include <sysdep.h> - - .syntax unified - .text - -@ Change &GOT[n+3] into 8*n. Note relocs are 8 bytes each. -.macro compute_reloc_arg pltgot, got2 - sub r1, \pltgot, \got2 @ r1 = &GOT[n+3] - &GOT[2] = 4*(n-1) - sub r1, r1, #4 @ r1 = 4*n - add r1, r1, r1 @ r1 *= 2 = 8*n -.endm - - CFI_SECTIONS - .globl _dl_runtime_resolve - .type _dl_runtime_resolve, %function - .p2align 4 -_dl_runtime_resolve: - cfi_startproc - cfi_adjust_cfa_offset (8) - - @ We get called with: - @ lr contains the return address from this call - @ stack[1] contains &GOT[n+3] (pointer to function) - @ stack[0] points to &GOT[2] - - ldr ip, [sp] @ ip gets &GOT[2] - - @ Save the argument registers and the return address. - @ r4 doesn't need to be saved, but it makes the total - @ adjustment to sp (including the two words pushed by - @ the PLT code) an even eight words, so sp stays aligned. - push {r0-r4, lr} - cfi_adjust_cfa_offset (24) - cfi_rel_offset (r0, 0) - cfi_rel_offset (r1, 4) - cfi_rel_offset (r2, 8) - cfi_rel_offset (r3, 12) - cfi_rel_offset (r4, 16) - cfi_rel_offset (lr, 20) - - ldr r1, [sp, #28] @ r1 gets &GOT[n+3] - - @ Get the 'struct link_map *' for the first argument to _dl_fixup. - sfi_breg ip, ldr r0, [\B, #-4] - - @ Get the reloc offset for the second argument to _dl_fixup. - compute_reloc_arg r1, ip - - @ This does the real work, and returns the real call target. - sfi_bl _dl_fixup - mov ip, r0 - - @ Restore the saved registers. - pop {r0-r4, lr} - cfi_adjust_cfa_offset (-24) - cfi_restore (r0) - cfi_restore (r1) - cfi_restore (r2) - cfi_restore (r3) - cfi_restore (r4) - cfi_restore (lr) - - @ Now compensate for the two words pushed by the PLT code. - sfi_sp add sp, #8 - cfi_adjust_cfa_offset (-8) - - @ Finally, jump to the newfound call target. - sfi_bx ip - - cfi_endproc - .size _dl_runtime_resolve, .-_dl_runtime_resolve - -#ifndef PROF - .globl _dl_runtime_profile - .type _dl_runtime_profile, #function - .p2align 4 -_dl_runtime_profile: - cfi_startproc - cfi_adjust_cfa_offset (8) - - @ We get called with: - @ lr contains the return address from this call - @ stack[1] contains &GOT[n+3] (pointer to function) - @ stack[0] points to &GOT[2] - - @ Stack layout: - @ sp + 204 framesize returned from pltenter - @ sp + 12 La_arm_regs - @ sp + 4 Saved two arguments to _dl_profile_fixup - @ sp + 0 outgoing argument to _dl_profile_fixup - @ For now, we only save the general purpose registers. -# define PLTEXIT_ARGS 4 -# define LA_ARM_REGS (PLTEXIT_ARGS + 8) -# define LA_ARM_REGS_SIZE (4 * (4 + 1 + 1 + 42)) -# define PLTENTER_FRAMESIZE (LA_ARM_REGS + LA_ARM_REGS_SIZE) -# define FRAMESIZE (((PLTENTER_FRAMESIZE + 4) + 15) & -16) - - @ The NaCl ABI requires that sp be aligned to 16 bytes at call - @ sites. Assuming that was met on entry to the PLT, sp is - @ now exactly 8 bytes misaligned. - sfi_sp sub sp, #(FRAMESIZE - 8) - cfi_def_cfa_offset (FRAMESIZE) - - @ Store the argument registers in La_arm_regs. - strd r0, r1, [sp, #LA_ARM_REGS] - cfi_offset (r0, LA_ARM_REGS + 0) - cfi_offset (r1, LA_ARM_REGS + 4) - strd r2, r3, [sp, #(LA_ARM_REGS + 8)] - cfi_offset (r2, LA_ARM_REGS + 8) - cfi_offset (r3, LA_ARM_REGS + 12) - - ldr ip, [sp, #(FRAMESIZE - 8)] @ ip gets &GOT[2] - ldr r3, [sp, #(FRAMESIZE - 4)] @ r3 gets &GOT[n+3] - - @ Recover the incoming sp and lr and save those in La_arm_regs. - add r0, sp, #FRAMESIZE - mov r1, lr - strd r0, r1, [sp, #(LA_ARM_REGS + 16)] - cfi_offset (sp, LA_ARM_REGS + 16) - cfi_offset (lr, LA_ARM_REGS + 20) - - @ Get the 'struct link_map *' for the first arg to _dl_profile_fixup. - sfi_breg ip, ldr r0, [\B, #-4] - - @ Get the reloc offset for the second argument to _dl_profile_fixup. - compute_reloc_arg r3, ip - - @ The third argument is the original return address, still in lr. - mov r2, lr - - @ Compute the fourth argument, the La_arm_regs pointer. - add r3, sp, #PLTEXIT_ARGS - - @ Compute the fifth argument, the address of the 'framesize' - @ out parameter, and store it at the top of the stack. - add ip, sp, #PLTENTER_FRAMESIZE - str ip, [sp] - - @ Save away the first two arguments, which we will need - @ again for _dl_call_pltexit, below. - strd r0, r1, [sp, #PLTEXIT_ARGS] - - @ This does the real work, and returns the real call target. - sfi_bl _dl_profile_fixup - - @ The address to call is now in r0. - - @ Check whether we're wrapping this function, - @ i.e. if the framesize out parameter is >= 0. - ldr ip, [sp, #PLTENTER_FRAMESIZE] - cmp ip, #0 - bge 1f - cfi_remember_state - - @ Save _dl_profile_fixup's return value: the real call target. - mov ip, r0 - - @ Restore the registers from the La_arm_regs (perhaps as modified - @ by audit modules' pltenter functions). - add r1, sp, #LA_ARM_REGS - sfi_sp sfi_breg r1, ldmia \B, {r0-r3, sp, lr} - cfi_def_cfa_offset (0) - cfi_restore (r0) - cfi_restore (r1) - cfi_restore (r2) - cfi_restore (r3) - cfi_restore (sp) - cfi_restore (lr) - - @ Finally, jump to the newfound call target. - sfi_bx ip - -1: cfi_restore_state - @ The new frame size is in ip. - - @ Save the fp in the stack slot previously used for the fifth - @ argument to _dl_profile_fixup. - str fp, [sp] - cfi_offset (fp, 0) - - @ Save the result of _dl_profile_fixup, the real call target. - @ We'll reuse the stack slot just used for the 'framesize' - @ out parameter to _dl_profile_fixup. - str r0, [sp, #PLTENTER_FRAMESIZE] - - @ Stack layout: - @ fp + 264 call target - @ fp + 72 La_arm_regs - @ fp + 68 Saved two arguments to _dl_profile_fixup - @ fp + 64 saved fp - @ fp + 0 La_arm_retval - @ sp..fp copied incoming stack space (plus alignment) - @ For now, we only save the general purpose registers. -# define FP_LA_ARM_RETVAL 0 -# define LA_ARM_RETVAL_SIZE (4 * (4 + 12)) -# define FP_SAVED_FP LA_ARM_RETVAL_SIZE -# define FP_PLTEXIT_ARGS (FP_SAVED_FP + 4) -# define FP_LA_ARM_REGS (FP_PLTEXIT_ARGS + 8) -# define FP_CALL_TARGET (FP_LA_ARM_REGS + LA_ARM_REGS_SIZE) -# define FP_FRAMESIZE (FP_CALL_TARGET + 4) - - sub fp, sp, #(FP_FRAMESIZE - FRAMESIZE) - cfi_def_cfa (fp, FP_FRAMESIZE) - - sub r1, fp, ip - @ This doesn't need sfi_sp because we just include the - @ sandboxing mask along with the alignment mask. - bic sp, r1, #0xc000000f - - @ Copy the stack arguments. The audit modules' pltenter - @ function(s) decided how much needs to be copied. - @ Load the sp as modified by pltenter functions, rather - @ than what we think the incoming sp was (fp + FP_FRAMESIZE). - sfi_breg fp, ldr r1, [\B, #(FP_LA_ARM_REGS + 16)] - mov r0, sp - mov r2, ip - sfi_bl memcpy - - @ Load up the arguments from La_arm_regs and call the user's function. - sfi_breg fp, ldr ip, [\B, #FP_CALL_TARGET] - sfi_breg fp, ldrd r0, r1, [\B, #FP_LA_ARM_REGS] - sfi_breg fp, ldrd r2, r3, [\B, #(FP_LA_ARM_REGS + 8)] - sfi_blx ip - - @ Stash the return value registers in La_arm_retval. - sfi_breg fp, strd r0, r1, [\B, #FP_LA_ARM_RETVAL] - sfi_breg fp, strd r2, r3, [\B, #(FP_LA_ARM_RETVAL + 8)] - - @ Call pltexit. We saved the first two arguments earlier--they - @ are the same ones passed to _dl_profile_fixup. The latter two - @ arguments are La_arm_regs and La_arm_retval blocks, respectively. - sfi_breg fp, ldrd r0, r1, [\B, #FP_PLTEXIT_ARGS] - add r2, fp, #FP_LA_ARM_REGS - add r3, fp, #FP_LA_ARM_RETVAL - sfi_bl _dl_call_pltexit - - @ Reload the saved return value registers for the caller. - sfi_breg fp, ldrd r0, r1, [\B, #FP_LA_ARM_RETVAL] - sfi_breg fp, ldrd r2, r3, [\B, #(FP_LA_ARM_RETVAL + 8)] - - @ Unwind the frame. - sfi_sp mov sp, fp - cfi_def_cfa_register (sp) - ldr fp, [sp, #FP_SAVED_FP] - cfi_restore (fp) - @ Reload the lr and sp values from La_arm_regs, where they - @ might have been modified by pltenter functions, rather than - @ computing what we think the incoming value was. - ldr lr, [sp, #(FP_LA_ARM_REGS + 20)] - cfi_restore (lr) - sfi_sp ldr sp, [sp, #(FP_LA_ARM_REGS + 16)] - cfi_def_cfa_offset (0) - - @ Finally, return to the caller. - sfi_bx lr - - cfi_endproc - .size _dl_runtime_profile, .-_dl_runtime_profile -#endif - .previous |