new file mode 100644
@@ -0,0 +1,5 @@
+#include <sysdep.h>
+#include <tls.h>
+#include <kernel-features.h>
+
+SIGSTATE_OFFSET offsetof (tcbprehead_t, _hurd_sigstate) - sizeof (tcbprehead_t)
new file mode 100644
@@ -0,0 +1,24 @@
+# Copyright (C) 2020-2024 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 ($(subdir),debug)
+gen-as-const-headers += signal-defines.sym
+endif
+
+ifeq ($(subdir),setjmp)
+gen-as-const-headers += signal-defines.sym
+endif
new file mode 100644
@@ -0,0 +1,173 @@
+/* Copyright (C) 1997-2024 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 <asm-syntax.h>
+#include <jmpbuf-offsets.h>
+#include <pointer_guard.h>
+#include <tcb-offsets.h>
+#include <signal-defines.h>
+#include <stap-probe.h>
+#include <sysdep.h>
+
+#define SS_ONSTACK 1
+#define SS_ONSTACK_BIT 0
+
+ .section .rodata.str1.1,"aMS",%progbits,1
+ .type longjmp_msg,%object
+longjmp_msg:
+ .string "longjmp causes uninitialized stack frame"
+ .size longjmp_msg, .-longjmp_msg
+ .text
+
+# define CALL_FAIL \
+ adrp x0, longjmp_msg; \
+ add x0, x0, :lo12:longjmp_msg; \
+ b HIDDEN_JUMPTARGET(__fortify_fail) \
+
+/* 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)
+ cfi_def_cfa(x0, 0)
+ cfi_offset(x19, JB_X19<<3)
+ cfi_offset(x20, JB_X20<<3)
+ cfi_offset(x21, JB_X21<<3)
+ cfi_offset(x22, JB_X22<<3)
+ cfi_offset(x23, JB_X23<<3)
+ cfi_offset(x24, JB_X24<<3)
+ cfi_offset(x25, JB_X25<<3)
+ cfi_offset(x26, JB_X26<<3)
+ cfi_offset(x27, JB_X27<<3)
+ cfi_offset(x28, JB_X28<<3)
+ cfi_offset(x29, JB_X29<<3)
+ cfi_offset(x30, JB_LR<<3)
+
+ cfi_offset( d8, JB_D8<<3)
+ cfi_offset( d9, JB_D9<<3)
+ cfi_offset(d10, JB_D10<<3)
+ cfi_offset(d11, JB_D11<<3)
+ cfi_offset(d12, JB_D12<<3)
+ cfi_offset(d13, JB_D13<<3)
+ cfi_offset(d14, JB_D14<<3)
+ cfi_offset(d15, JB_D15<<3)
+
+ PTR_ARG (0)
+
+ ldp x19, x20, [x0, #JB_X19<<3]
+ ldp x21, x22, [x0, #JB_X21<<3]
+ ldp x23, x24, [x0, #JB_X23<<3]
+ ldp x25, x26, [x0, #JB_X25<<3]
+ ldp x27, x28, [x0, #JB_X27<<3]
+#ifdef PTR_DEMANGLE
+ ldp x29, x4, [x0, #JB_X29<<3]
+ PTR_DEMANGLE (30, 4, 3, 2)
+#else
+ ldp x29, x30, [x0, #JB_X29<<3]
+#endif
+ /* longjmp probe takes 3 arguments, address of jump buffer as
+ first argument (8@x0), return value as second argument (-4@x1),
+ and target address (8@x30), respectively. */
+ LIBC_PROBE (longjmp, 3, 8@x0, -4@x1, 8@x30)
+ ldp d8, d9, [x0, #JB_D8<<3]
+ ldp d10, d11, [x0, #JB_D10<<3]
+ ldp d12, d13, [x0, #JB_D12<<3]
+ ldp d14, d15, [x0, #JB_D14<<3]
+
+ /* Originally this was implemented with a series of
+ .cfi_restore() directives.
+
+ The theory was that cfi_restore should revert to previous
+ frame value is the same as the current value. In practice
+ this doesn't work, even after cfi_restore() gdb continues
+ to try to recover a previous frame value offset from x0,
+ which gets stuffed after a few more instructions. The
+ cfi_same_value() mechanism appears to work fine. */
+
+ cfi_same_value(x19)
+ cfi_same_value(x20)
+ cfi_same_value(x21)
+ cfi_same_value(x22)
+ cfi_same_value(x23)
+ cfi_same_value(x24)
+ cfi_same_value(x25)
+ cfi_same_value(x26)
+ cfi_same_value(x27)
+ cfi_same_value(x28)
+ cfi_same_value(x29)
+ cfi_same_value(x30)
+ cfi_same_value(d8)
+ cfi_same_value(d9)
+ cfi_same_value(d10)
+ cfi_same_value(d11)
+ cfi_same_value(d12)
+ cfi_same_value(d13)
+ cfi_same_value(d14)
+ cfi_same_value(d15)
+#ifdef PTR_DEMANGLE
+ ldr x4, [x0, #JB_SP<<3]
+ PTR_DEMANGLE (5, 4, 3, 2)
+#else
+ ldr x5, [x0, #JB_SP<<3]
+#endif
+
+ mrs x3, tpidr_el0
+#if !defined (SHARED) || IS_IN (rtld)
+ cbz x3, L(ok) /* TLS not initialized yet */
+#endif
+ ldr x3, [x3, #SIGSTATE_OFFSET]
+ cbz x3, L(ok) /* sigstate not initialized yet */
+
+ ldrb w4, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)]
+ tbnz w4, #SS_ONSTACK_BIT, L(onstack)
+ /* We haven't been using an altstack. Jumping to a higher-address
+ frame is always allowed, otherwise it's not allowed. */
+ mov x6, sp
+ cmp x5, x6
+ b.lt L(ok)
+
+L(fail):
+ CALL_FAIL
+
+L(onstack):
+ /* We have been using an altstack. Was it above or below ours? */
+ ldr x2, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)]
+ cmp x2, x5
+ b.lt L(oks) /* Jumping below the altstack, switch */
+ ldr x6, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)]
+ add x2, x2, x6
+ cmp x2, x5
+ b.lt L(ok) /* Jumping inside the altstack, do not switch */
+
+ /* Jumping above the altstack, switch */
+L(oks):
+ and w4, w4, #~(SS_ONSTACK)
+ str w4, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)]
+L(ok):
+ mov sp, x5
+
+ /* longjmp_target probe takes 3 arguments, address of jump buffer
+ as first argument (8@x0), return value as second argument (-4@x1),
+ and target address (8@x30), respectively. */
+ LIBC_PROBE (longjmp_target, 3, 8@x0, -4@x1, 8@x30)
+ cmp x1, #0
+ mov x0, #1
+ csel x0, x1, x0, ne
+ /* Use br instead of ret because ret is guaranteed to mispredict */
+ br x30
+END (____longjmp_chk)
new file mode 100644
@@ -0,0 +1,150 @@
+/* Copyright (C) 1997-2024 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 <asm-syntax.h>
+#include <jmpbuf-offsets.h>
+#include <pointer_guard.h>
+#include <tcb-offsets.h>
+#include <signal-defines.h>
+#include <stap-probe.h>
+#include <sysdep.h>
+
+#define SS_ONSTACK 1
+#define SS_ONSTACK_BIT 0
+
+/* __longjmp(jmpbuf, val) */
+
+ENTRY (__longjmp)
+ cfi_def_cfa(x0, 0)
+ cfi_offset(x19, JB_X19<<3)
+ cfi_offset(x20, JB_X20<<3)
+ cfi_offset(x21, JB_X21<<3)
+ cfi_offset(x22, JB_X22<<3)
+ cfi_offset(x23, JB_X23<<3)
+ cfi_offset(x24, JB_X24<<3)
+ cfi_offset(x25, JB_X25<<3)
+ cfi_offset(x26, JB_X26<<3)
+ cfi_offset(x27, JB_X27<<3)
+ cfi_offset(x28, JB_X28<<3)
+ cfi_offset(x29, JB_X29<<3)
+ cfi_offset(x30, JB_LR<<3)
+
+ cfi_offset( d8, JB_D8<<3)
+ cfi_offset( d9, JB_D9<<3)
+ cfi_offset(d10, JB_D10<<3)
+ cfi_offset(d11, JB_D11<<3)
+ cfi_offset(d12, JB_D12<<3)
+ cfi_offset(d13, JB_D13<<3)
+ cfi_offset(d14, JB_D14<<3)
+ cfi_offset(d15, JB_D15<<3)
+
+ PTR_ARG (0)
+
+ ldp x19, x20, [x0, #JB_X19<<3]
+ ldp x21, x22, [x0, #JB_X21<<3]
+ ldp x23, x24, [x0, #JB_X23<<3]
+ ldp x25, x26, [x0, #JB_X25<<3]
+ ldp x27, x28, [x0, #JB_X27<<3]
+#ifdef PTR_DEMANGLE
+ ldp x29, x4, [x0, #JB_X29<<3]
+ PTR_DEMANGLE (30, 4, 3, 2)
+#else
+ ldp x29, x30, [x0, #JB_X29<<3]
+#endif
+ /* longjmp probe takes 3 arguments, address of jump buffer as
+ first argument (8@x0), return value as second argument (-4@x1),
+ and target address (8@x30), respectively. */
+ LIBC_PROBE (longjmp, 3, 8@x0, -4@x1, 8@x30)
+ ldp d8, d9, [x0, #JB_D8<<3]
+ ldp d10, d11, [x0, #JB_D10<<3]
+ ldp d12, d13, [x0, #JB_D12<<3]
+ ldp d14, d15, [x0, #JB_D14<<3]
+
+ /* Originally this was implemented with a series of
+ .cfi_restore() directives.
+
+ The theory was that cfi_restore should revert to previous
+ frame value is the same as the current value. In practice
+ this doesn't work, even after cfi_restore() gdb continues
+ to try to recover a previous frame value offset from x0,
+ which gets stuffed after a few more instructions. The
+ cfi_same_value() mechanism appears to work fine. */
+
+ cfi_same_value(x19)
+ cfi_same_value(x20)
+ cfi_same_value(x21)
+ cfi_same_value(x22)
+ cfi_same_value(x23)
+ cfi_same_value(x24)
+ cfi_same_value(x25)
+ cfi_same_value(x26)
+ cfi_same_value(x27)
+ cfi_same_value(x28)
+ cfi_same_value(x29)
+ cfi_same_value(x30)
+ cfi_same_value(d8)
+ cfi_same_value(d9)
+ cfi_same_value(d10)
+ cfi_same_value(d11)
+ cfi_same_value(d12)
+ cfi_same_value(d13)
+ cfi_same_value(d14)
+ cfi_same_value(d15)
+#ifdef PTR_DEMANGLE
+ ldr x4, [x0, #JB_SP<<3]
+ PTR_DEMANGLE (5, 4, 3, 2)
+#else
+ ldr x5, [x0, #JB_SP<<3]
+#endif
+
+ mrs x3, tpidr_el0
+#if !defined (SHARED) || IS_IN (rtld)
+ cbz x3, L(ok) /* TLS not initialized yet */
+#endif
+ ldr x3, [x3, #SIGSTATE_OFFSET]
+ cbz x3, L(ok) /* sigstate not initialized yet */
+ /* If we haven't been using an altstack, don't switch */
+ ldrb w4, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)]
+ tbz w4, #SS_ONSTACK_BIT, L(ok)
+
+ /* We have been using an altstack. Was it above or below ours? */
+ ldr x2, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)]
+ cmp x2, x5
+ b.lt L(oks) /* Jumping below the altstack, switch */
+ ldr x6, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)]
+ add x2, x2, x6
+ cmp x2, x5
+ b.lt L(ok) /* Jumping inside the altstack, do not switch */
+
+ /* Jumping above the altstack, switch */
+L(oks):
+ and w4, w4, #~(SS_ONSTACK)
+ str w4, [x3, # (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)]
+L(ok):
+ mov sp, x5
+
+ /* longjmp_target probe takes 3 arguments, address of jump buffer
+ as first argument (8@x0), return value as second argument (-4@x1),
+ and target address (8@x30), respectively. */
+ LIBC_PROBE (longjmp_target, 3, 8@x0, -4@x1, 8@x30)
+ cmp x1, #0
+ mov x0, #1
+ csel x0, x1, x0, ne
+ /* Use br instead of ret because ret is guaranteed to mispredict */
+ br x30
+END (__longjmp)
new file mode 100644
@@ -0,0 +1,10 @@
+#include <hurd/signal.h>
+#include <signal.h>
+
+--
+
+HURD_SIGSTATE__SIGALTSTACK__OFFSET offsetof(struct hurd_sigstate, sigaltstack)
+
+SIGALTSTACK__SS_SP__OFFSET offsetof(stack_t, ss_sp)
+SIGALTSTACK__SS_SIZE__OFFSET offsetof(stack_t, ss_size)
+SIGALTSTACK__SS_FLAGS__OFFSET offsetof(stack_t, ss_flags)
This is based on the generic AArch64 version, but it additionally respects and updates the Hurd sigstate. Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> --- This is also entirely untested. Please review carefully. sysdeps/aarch64/htl/tcb-offsets.sym | 5 + sysdeps/mach/hurd/aarch64/Makefile | 24 +++ sysdeps/mach/hurd/aarch64/____longjmp_chk.S | 173 +++++++++++++++++++ sysdeps/mach/hurd/aarch64/__longjmp.S | 150 ++++++++++++++++ sysdeps/mach/hurd/aarch64/signal-defines.sym | 10 ++ 5 files changed, 362 insertions(+) create mode 100644 sysdeps/aarch64/htl/tcb-offsets.sym create mode 100644 sysdeps/mach/hurd/aarch64/Makefile create mode 100644 sysdeps/mach/hurd/aarch64/____longjmp_chk.S create mode 100644 sysdeps/mach/hurd/aarch64/__longjmp.S create mode 100644 sysdeps/mach/hurd/aarch64/signal-defines.sym