Applied, thanks! Sergey Bugaev, le sam. 29 avril 2023 23:18:18 +0300, a ecrit: > Checked on x86_64-gnu. > > Signed-off-by: Sergey Bugaev <buga...@gmail.com> > --- > I have checked that setjmp/longjmp actually works sucessfully, with both > __longjmp and ____longjmp_chk. I have not been able to check w/ sigaltstack > because we don't yet have the proc server and signals. > > Changes since v1: > - drop the separate non-PIC version, we can always use %rip-relative access > on x86_64, and that's what the compiler generates anyway even with -fno-pic; > - use "cmpb $0, __libc_tls_initialized(%rip)" over > "movb __libc_tls_initialized(%rip), %r10b; testb %r10b, %r10b" -- the former > is what the compiler generates, so better be consistent. > > sysdeps/mach/hurd/x86_64/____longjmp_chk.S | 118 +++++++++++++++++++++ > sysdeps/mach/hurd/x86_64/__longjmp.S | 96 +++++++++++++++++ > 2 files changed, 214 insertions(+) > create mode 100644 sysdeps/mach/hurd/x86_64/____longjmp_chk.S > create mode 100644 sysdeps/mach/hurd/x86_64/__longjmp.S > > diff --git a/sysdeps/mach/hurd/x86_64/____longjmp_chk.S > b/sysdeps/mach/hurd/x86_64/____longjmp_chk.S > new file mode 100644 > index 00000000..935b8575 > --- /dev/null > +++ b/sysdeps/mach/hurd/x86_64/____longjmp_chk.S > @@ -0,0 +1,118 @@ > +/* Checked longjmp support. x86_64 Hurd version. > + Copyright (C) 2001-2023 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 > + <https://www.gnu.org/licenses/>. */ > + > +#include <sysdep.h> > +#include <pointer_guard.h> > +#include <jmpbuf-offsets.h> > +#include <asm-syntax.h> > +#include <tcb-offsets.h> > +#include <jmp_buf-ssp.h> > +#include <signal-defines.h> > + > +#define SS_ONSTACK 1 > + > +/* Don't restore shadow stack register if shadow stack isn't enabled. */ > +#if !SHSTK_ENABLED > +# undef SHADOW_STACK_POINTER_OFFSET > +#endif > + > + .section .rodata.str1.1,"aMS",@progbits,1 > + .type longjmp_msg,@object > +longjmp_msg: > + .string "longjmp causes uninitialized stack frame" > + .size longjmp_msg, .-longjmp_msg > + > + > +# define CALL_FAIL sub $8, %RSP_LP; \ > + cfi_remember_state; \ > + cfi_def_cfa_offset(16); \ > + lea longjmp_msg(%rip), %RDI_LP; \ > + call HIDDEN_JUMPTARGET(__fortify_fail); \ > + nop; \ > + cfi_restore_state > + > +/* Jump to the position specified by ENV, causing the > + setjmp call there to return VAL, or 1 if VAL is 0. > + void __longjmp (__jmp_buf env, int val). */ > + .text > +ENTRY(____longjmp_chk) > + /* Restore registers. */ > + mov (JB_RSP*8)(%rdi), %R8_LP > + mov (JB_RBP*8)(%rdi),%R9_LP > + mov (JB_PC*8)(%rdi), %RDX_LP > +#ifdef PTR_DEMANGLE > + PTR_DEMANGLE (%R8_LP) > + PTR_DEMANGLE (%R9_LP) > + PTR_DEMANGLE (%RDX_LP) > +#endif > + > +#if !defined (SHARED) || IS_IN (rtld) > + cmpb $0, __libc_tls_initialized(%rip) > + jz .Lok /* TLS not initialized yet */ > +#endif > + > + movq %fs:SIGSTATE_OFFSET, %R10_LP > + testq %R10_LP, %R10_LP > + jz .Lok /* sigstate not initialized yet */ > + > + testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + > SIGALTSTACK__SS_FLAGS__OFFSET)(%R10_LP) > + jnz .Lonstack > + > + /* We were on the main stack. Jumping to a higher-address > + frame is always allowed, otherwise it's not allowed. */ > + cmp %R8_LP, %RSP_LP > + jbe .Lok > + > +.Lfail: CALL_FAIL > + > +.Lonstack: > + cmpq (HURD_SIGSTATE__SIGALTSTACK__OFFSET + > SIGALTSTACK__SS_SP__OFFSET)(%R10_LP), %R8_LP > + jb .Loks /* Jumping below the altstack, switch */ > + > + movq (HURD_SIGSTATE__SIGALTSTACK__OFFSET + > SIGALTSTACK__SS_SP__OFFSET)(%R10_LP), %R11_LP > + addq (HURD_SIGSTATE__SIGALTSTACK__OFFSET + > SIGALTSTACK__SS_SIZE__OFFSET)(%R10_LP), %R11_LP > + cmpq %R11_LP, %R8_LP > + jb .Lok /* Jumping inside the altstack, do not switch */ > + > + /* Jumping above the altstack, switch */ > + > +.Loks: > + andl $~(SS_ONSTACK), (HURD_SIGSTATE__SIGALTSTACK__OFFSET + > SIGALTSTACK__SS_FLAGS__OFFSET)(%R10_LP) > + > +.Lok: > + /* We add unwind information for the target here. */ > + cfi_def_cfa(%rdi, 0) > + cfi_register(%rsp,%r8) > + cfi_register(%rbp,%r9) > + cfi_register(%rip,%rdx) > + cfi_offset(%rbx,JB_RBX*8) > + cfi_offset(%r12,JB_R12*8) > + cfi_offset(%r13,JB_R13*8) > + cfi_offset(%r14,JB_R14*8) > + cfi_offset(%r15,JB_R15*8) > + movq (JB_RBX*8)(%rdi), %rbx > + movq (JB_R12*8)(%rdi), %r12 > + movq (JB_R13*8)(%rdi), %r13 > + movq (JB_R14*8)(%rdi), %r14 > + movq (JB_R15*8)(%rdi), %r15 > + /* Set return value for setjmp. */ > + movl %esi, %eax > + mov %R8_LP, %RSP_LP > + movq %r9,%rbp > + jmpq *%rdx > +END (____longjmp_chk) > diff --git a/sysdeps/mach/hurd/x86_64/__longjmp.S > b/sysdeps/mach/hurd/x86_64/__longjmp.S > new file mode 100644 > index 00000000..389c1d16 > --- /dev/null > +++ b/sysdeps/mach/hurd/x86_64/__longjmp.S > @@ -0,0 +1,96 @@ > +/* longjmp support. x86_64/Hurd version. > + Copyright (C) 2001-2023 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 > + <https://www.gnu.org/licenses/>. */ > + > +#include <sysdep.h> > +#include <pointer_guard.h> > +#include <jmpbuf-offsets.h> > +#include <asm-syntax.h> > +#include <tcb-offsets.h> > +#include <jmp_buf-ssp.h> > +#include <signal-defines.h> > + > +#define SS_ONSTACK 1 > + > +/* Don't restore shadow stack register if shadow stack isn't enabled. */ > +#if !SHSTK_ENABLED > +# undef SHADOW_STACK_POINTER_OFFSET > +#endif > + > +/* Jump to the position specified by ENV, causing the > + setjmp call there to return VAL, or 1 if VAL is 0. > + void __longjmp (__jmp_buf env, int val). */ > + .text > +ENTRY(__longjmp) > + /* Restore registers. */ > + mov (JB_RSP*8)(%rdi), %R8_LP > + mov (JB_RBP*8)(%rdi),%R9_LP > + mov (JB_PC*8)(%rdi), %RDX_LP > +#ifdef PTR_DEMANGLE > + PTR_DEMANGLE (%R8_LP) > + PTR_DEMANGLE (%R9_LP) > + PTR_DEMANGLE (%RDX_LP) > +#endif > + > +#if !defined (SHARED) || IS_IN (rtld) > + cmpb $0, __libc_tls_initialized(%rip) > + jz .Lok /* TLS not initialized yet */ > +#endif > + > + movq %fs:SIGSTATE_OFFSET, %R10_LP > + testq %R10_LP, %R10_LP > + jz .Lok /* sigstate not initialized yet */ > + > + testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + > SIGALTSTACK__SS_FLAGS__OFFSET)(%R10_LP) > + jz .Lok > + > +.Lonstack: > + cmpq (HURD_SIGSTATE__SIGALTSTACK__OFFSET + > SIGALTSTACK__SS_SP__OFFSET)(%R10_LP), %R8_LP > + jb .Loks /* Jumping below the altstack, switch */ > + > + movq (HURD_SIGSTATE__SIGALTSTACK__OFFSET + > SIGALTSTACK__SS_SP__OFFSET)(%R10_LP), %R11_LP > + addq (HURD_SIGSTATE__SIGALTSTACK__OFFSET + > SIGALTSTACK__SS_SIZE__OFFSET)(%R10_LP), %R11_LP > + cmpq %R11_LP, %R8_LP > + jb .Lok /* Jumping inside the altstack, do not switch */ > + > + /* Jumping above the altstack, switch */ > + > +.Loks: > + andl $~(SS_ONSTACK), (HURD_SIGSTATE__SIGALTSTACK__OFFSET + > SIGALTSTACK__SS_FLAGS__OFFSET)(%R10_LP) > + > +.Lok: > + /* We add unwind information for the target here. */ > + cfi_def_cfa(%rdi, 0) > + cfi_register(%rsp,%r8) > + cfi_register(%rbp,%r9) > + cfi_register(%rip,%rdx) > + cfi_offset(%rbx,JB_RBX*8) > + cfi_offset(%r12,JB_R12*8) > + cfi_offset(%r13,JB_R13*8) > + cfi_offset(%r14,JB_R14*8) > + cfi_offset(%r15,JB_R15*8) > + movq (JB_RBX*8)(%rdi), %rbx > + movq (JB_R12*8)(%rdi), %r12 > + movq (JB_R13*8)(%rdi), %r13 > + movq (JB_R14*8)(%rdi), %r14 > + movq (JB_R15*8)(%rdi), %r15 > + /* Set return value for setjmp. */ > + movl %esi, %eax > + mov %R8_LP, %RSP_LP > + movq %r9,%rbp > + jmpq *%rdx > +END (__longjmp) > -- > 2.40.1 >
-- Samuel --- Pour une évaluation indépendante, transparente et rigoureuse ! Je soutiens la Commission d'Évaluation de l'Inria.
