hurd: fix clearing SS_ONSTACK when longjmp-ing from sighandler

* sysdeps/i386/htl/Makefile: New file.
* sysdeps/i386/htl/tcb-offsets.sym: New file.
* sysdeps/mach/hurd/i386/Makefile [setjmp] (gen-as-const-headers): Add
signal-defines.sym.
* sysdeps/mach/hurd/i386/____longjmp_chk.S: Include tcb-offsets.h.
(____longjmp_chk): Harmonize with i386's __longjmp. Clear SS_ONSTACK
when jumping off the alternate stack.
* sysdeps/mach/hurd/i386/__longjmp.S: New file.
This commit is contained in:
Samuel Thibault 2020-06-06 20:21:22 +02:00
parent 8fcc772da8
commit 02937d825a
5 changed files with 154 additions and 32 deletions

20
sysdeps/i386/htl/Makefile Normal file
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@ -0,0 +1,20 @@
# Copyright (C) 2020 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/>.
ifeq ($(subdir),csu)
gen-as-const-headers += tcb-offsets.sym
endif

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@ -0,0 +1,8 @@
#include <sysdep.h>
#include <tls.h>
#include <kernel-features.h>
MULTIPLE_THREADS_OFFSET offsetof (tcbhead_t, multiple_threads)
SYSINFO_OFFSET offsetof (tcbhead_t, sysinfo)
POINTER_GUARD offsetof (tcbhead_t, pointer_guard)
SIGSTATE_OFFSET offsetof (tcbhead_t, _hurd_sigstate)

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@ -7,6 +7,10 @@ ifeq ($(subdir),debug)
gen-as-const-headers += signal-defines.sym
endif
ifeq ($(subdir),setjmp)
gen-as-const-headers += signal-defines.sym
endif
ifeq ($(subdir),csu)
ifeq (yes,$(build-shared))
sysdep_routines += divdi3

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@ -17,6 +17,7 @@
#include <sysdep.h>
#include <jmpbuf-offsets.h>
#include <tcb-offsets.h>
#include <asm-syntax.h>
#include <signal-defines.h>
@ -47,65 +48,70 @@ longjmp_msg:
.text
ENTRY (____longjmp_chk)
movl 4(%esp), %ecx /* User's jmp_buf in %ecx. */
movl 4(%esp), %eax /* User's jmp_buf in %eax. */
/* Save the return address now. */
movl (JB_PC*4)(%ecx), %edx
movl (JB_PC*4)(%eax), %edx
/* Get the stack pointer. */
movl (JB_SP*4)(%ecx), %edi
cfi_undefined(%edi)
movl (JB_SP*4)(%eax), %ecx
cfi_undefined(%ecx)
#ifdef PTR_DEMANGLE
PTR_DEMANGLE (%edx)
PTR_DEMANGLE (%edi)
PTR_DEMANGLE (%ecx)
#endif
cmpl %edi, %esp
movl %gs:SIGSTATE_OFFSET,%edi
testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi)
jnz .Lonstack
/* We were on the main stack */
cmpl %ecx, %esp
/* Jumping to a higher-address frame is always allowed. */
jbe .Lok
/* Passing here, we're either about to do something invalid, or we're
executing on an alternative signal stack. */
/* Otherwise it's not allowed. */
CALL_FAIL
/* TODO: need locking? */
/* struct hurd_sigstate * _hurd_self_sigstate (void) */
call HIDDEN_JUMPTARGET(_hurd_self_sigstate)
/* TODO: %eax and %eax->sigaltstack are always valid? */
.Lonstack:
/* We were on the alternate stack, can't really easily check anything
since longjmp may get us out of the alternate stack. */
testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%eax)
/* Fail if SS_ONSTACK is not set. */
jz .Lfail
cmpl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ecx
jb .Loks /* We jump below the alternate stack, switch. */
movl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%eax), %ebx
addl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%eax), %ebx
subl %edi, %ebx
cmpl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%eax), %ebx
/* TODO: comment this calculation. */
jae .Lok
movl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ebx
addl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%edi), %ebx
cmpl %ebx, %ecx
jb .Lok /* We jump inside the alternate stack, do not switch. */
.Lfail: CALL_FAIL
/* We jump above the alternate stack, switch. */
.Loks: /* We jump out of the alternate stack, clear SS_ONSTACK flag. */
andl $~(SS_ONSTACK), (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi)
.Lok: /* We add unwind information for the target here. */
cfi_def_cfa(%ecx, 0)
cfi_def_cfa(%eax, 0)
cfi_register(%eip, %edx)
cfi_register(%esp, %edi)
cfi_register(%esp, %ecx)
cfi_offset(%ebx, JB_BX*4)
cfi_offset(%esi, JB_SI*4)
cfi_offset(%edi, JB_DI*4)
cfi_offset(%ebp, JB_BP*4)
movl 8(%esp), %eax /* Second argument is return value. */
movl %edi, %esp
/* Restore registers. */
movl (JB_BX*4)(%ecx), %ebx
movl (JB_SI*4)(%ecx), %esi
movl (JB_DI*4)(%ecx), %edi
movl (JB_BP*4)(%ecx), %ebp
movl (JB_BX*4)(%eax), %ebx
movl (JB_SI*4)(%eax), %esi
movl (JB_DI*4)(%eax), %edi
movl (JB_BP*4)(%eax), %ebp
cfi_restore(%ebx)
cfi_restore(%esi)
cfi_restore(%edi)
cfi_restore(%ebp)
movl 8(%esp), %eax /* Second argument is return value. */
movl %ecx, %esp
/* Jump to saved PC. */
jmp *%edx
END (____longjmp_chk)

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@ -0,0 +1,84 @@
/* Copyright (C) 2001-2020 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 <jmpbuf-offsets.h>
#include <tcb-offsets.h>
#include <asm-syntax.h>
#include <signal-defines.h>
/* #include <signal.h> */
#define SS_ONSTACK 1
.text
ENTRY (__longjmp)
movl 4(%esp), %eax /* User's jmp_buf in %eax. */
/* Save the return address now. */
movl (JB_PC*4)(%eax), %edx
/* Get the stack pointer. */
movl (JB_SP*4)(%eax), %ecx
cfi_undefined(%ecx)
#ifdef PTR_DEMANGLE
PTR_DEMANGLE (%edx)
PTR_DEMANGLE (%ecx)
#endif
movl %gs:SIGSTATE_OFFSET,%edi
testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi)
jz .Lok
/* We were on the alternate stack. */
cmpl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ecx
jb .Loks /* We jump below the alternate stack, switch. */
movl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ebx
addl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%edi), %ebx
cmpl %ebx, %ecx
jb .Lok /* We jump inside the alternate stack, do not switch. */
/* We jump above the alternate stack, switch. */
.Loks: /* We jump out of the alternate stack, clear SS_ONSTACK flag. */
andl $~(SS_ONSTACK), (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi)
.Lok: /* We add unwind information for the target here. */
cfi_def_cfa(%eax, 0)
cfi_register(%eip, %edx)
cfi_register(%esp, %ecx)
cfi_offset(%ebx, JB_BX*4)
cfi_offset(%esi, JB_SI*4)
cfi_offset(%edi, JB_DI*4)
cfi_offset(%ebp, JB_BP*4)
/* Restore registers. */
movl (JB_BX*4)(%eax), %ebx
movl (JB_SI*4)(%eax), %esi
movl (JB_DI*4)(%eax), %edi
movl (JB_BP*4)(%eax), %ebp
cfi_restore(%ebx)
cfi_restore(%esi)
cfi_restore(%edi)
cfi_restore(%ebp)
movl 8(%esp), %eax /* Second argument is return value. */
movl %ecx, %esp
/* Jump to saved PC. */
jmp *%edx
END (__longjmp)