[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[RFC PATCH glibc 17/34] hurd: Implement x86_64/intr-msg.h
From: |
Sergey Bugaev |
Subject: |
[RFC PATCH glibc 17/34] hurd: Implement x86_64/intr-msg.h |
Date: |
Sun, 19 Mar 2023 18:10:00 +0300 |
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
---
This is a prelimenary version of intr-msg.h. I can't know whether or not
it works until we can test it. The code relies on syscall preserving values
of the registers used to pass syscall arguments. The code in SYSCALL_EXAMINE
that just compares two bytes to the encoded syscall instruction is sure to
give many false positives; we're going to need to come up with a more reliable
scheme.
sysdeps/mach/hurd/x86_64/intr-msg.h | 119 ++++++++++++++++++++++++++++
1 file changed, 119 insertions(+)
create mode 100644 sysdeps/mach/hurd/x86_64/intr-msg.h
diff --git a/sysdeps/mach/hurd/x86_64/intr-msg.h
b/sysdeps/mach/hurd/x86_64/intr-msg.h
new file mode 100644
index 00000000..5d94c85f
--- /dev/null
+++ b/sysdeps/mach/hurd/x86_64/intr-msg.h
@@ -0,0 +1,119 @@
+/* Machine-dependent details of interruptible RPC messaging. x86_64 version.
+ Copyright (C) 1995-2023 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/>. */
+
+
+/* Note that we must mark OPTION and TIMEOUT as outputs of this operation,
+ to indicate that the signal thread might mutate them as part
+ of sending us to a signal handler. */
+
+#define INTR_MSG_TRAP(msg, option, send_size, rcv_size, rcv_name, timeout,
notify, cancel_p, intr_port_p) \
+({ \
+ error_t err; \
+ register uintptr_t rcv_size_r10 asm ("r10") = rcv_size; \
+ register uintptr_t rcv_name_r8 asm ("r8") = rcv_name;
\
+ register uintptr_t timeout_r9 asm ("r9") = timeout; \
+ asm volatile ( \
+ ".globl _hurd_intr_rpc_msg_about_to\n" \
+ ".globl _hurd_intr_rpc_msg_setup_done\n"
\
+ ".globl _hurd_intr_rpc_msg_in_trap\n" \
+ /* Clear rax before we do the check for cancel below. This is to
+ detect rax being set to non-zero (actually MACH_SEND_INTERRUPTED)
+ from the outside (namely, _hurdsig_abort_rpcs), which signals us
+ to skip the trap we were about to enter. */ \
+ " xor %[err], %[err]\n" \
+ "_hurd_intr_rpc_msg_about_to:" \
+ /* We need to make a last check of cancel, in case we got interrupted
+ right before _hurd_intr_rpc_msg_about_to. */
\
+ " cmpl $0, %[cancel]\n" \
+ " jz _hurd_intr_rpc_msg_do\n" \
+ /* We got interrupted, note so and return EINTR. */ \
+ " movl $0, %[intr_port]\n" \
+ " movl %[eintr], %[err]\n" \
+ " jmp _hurd_intr_rpc_msg_sp_restored\n" \
+ "_hurd_intr_rpc_msg_do:"
\
+ /* Ok, prepare the mach_msg_trap arguments. We pass the first 6 args
+ in registers, and push the last one and a fake return address. */ \
+ " pushq %[notify]\n" \
+ " pushq $0\n" \
+ "_hurd_intr_rpc_msg_setup_done:"
\
+ /* From here on, it is safe to make us jump over the syscall. Now
+ check if we have been told to skip the syscall while running
+ the above. */ \
+ " test %[err], %[err]\n" \
+ " jnz _hurd_intr_rpc_msg_in_trap\n" \
+ /* Do the actual syscall. */ \
+ " movq $-25, %%rax\n" \
+ "_hurd_intr_rpc_msg_do_trap: syscall # status in %[err]\n" \
+ "_hurd_intr_rpc_msg_in_trap:" \
+ /* Clean the arguments. */ \
+ " addq $16, %%rsp\n" \
+ "_hurd_intr_rpc_msg_sp_restored:" \
+ : [err] "=&a" (err), "+S" (option), [intr_port] "=m" (*intr_port_p), \
+ "+r" (timeout_r9) \
+ : "D" (msg), "d" (send_size), "r" (rcv_size_r10), "r" (rcv_name_r8), \
+ [notify] "rm" ((uintptr_t) notify), [cancel] "m" (*cancel_p), \
+ [eintr] "i" (EINTR) \
+ : "rcx", "r11");
\
+ timeout = timeout_r9;
\
+ err; \
+})
+
+#include "hurdfault.h"
+
+/* This cannot be an inline function because it calls setjmp. */
+#define SYSCALL_EXAMINE(state, callno) \
+({ \
+ struct { unsigned char c[2]; } *p = (void *) ((state)->rip - 2); \
+ int result; \
+ if (_hurdsig_catch_memory_fault (p)) \
+ return 0; \
+ if (result = p->c[0] == 0xf && p->c[1] == 0x5) \
+ /* The PC appears to be just after a `syscall' instruction.
\
+ This is a system call in progress; %rax holds the call number. */ \
+ *(callno) = (state)->rax; \
+ _hurdsig_end_catch_fault (); \
+ result; \
+})
+
+
+/* This cannot be an inline function because it calls setjmp. */
+#define MSG_EXAMINE(state, msgid, rcvname, send_name, opt, tmout) \
+({ \
+ int ret = 0; \
+ const struct machine_thread_state *s = (state); \
+ const mach_msg_header_t *msg = (const void *) s->rdi;
\
+ *(rcvname) = s->r8; \
+ *(opt) = s->rsi; \
+ *(tmout) = s->r9; \
+ if (msg == 0)
\
+ { \
+ *(send_name) = MACH_PORT_NULL; \
+ *(msgid) = 0; \
+ } \
+ else \
+ { \
+ ret = _hurdsig_catch_memory_fault (msg) ? -1 : 0;
\
+ if (ret == 0) \
+ { \
+ *(send_name) = msg->msgh_remote_port;
\
+ *(msgid) = msg->msgh_id; \
+ _hurdsig_end_catch_fault (); \
+ } \
+ } \
+ ret; \
+})
--
2.39.2
- [RFC PATCH glibc 09/34] hurd: Fix _hurd_setup_sighandler () signature, (continued)
- [RFC PATCH glibc 09/34] hurd: Fix _hurd_setup_sighandler () signature, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 06/34] hurd: Swap around two function calls, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 07/34] hurd: Fix file name in #error, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 12/34] hurd: More 64-bit integer casting fixes, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 13/34] x86-64: Disable prefer_map_32bit_exec tunable on non-Linux, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 14/34] hurd: Move rtld-strncpy-c.c out of mach/hurd/, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 15/34] hurd: Use uintptr_t for register values in trampoline.c, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 10/34] stdio-common: Fix building when !IS_IN (libc), Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 11/34] mach, hurd: Drop __libc_lock_self0, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 08/34] hurd: Disable O_TRUNC and FS_RETRY_MAGICAL in rtld, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 17/34] hurd: Implement x86_64/intr-msg.h,
Sergey Bugaev <=
- [RFC PATCH glibc 16/34] hurd: Add sys/ucontext.h and sigcontext.h for x86_64, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 18/34] hurd: Port trampoline.c to x86_64, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 19/34] hurd: Move a couple of singal-related files to x86, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 24/34] hurd: Only check for TLS initialization inside rtld or in static builds, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 21/34] x86_64: Add rtld-stpncpy & rtld-strncpy, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 23/34] elf: Stop including tls.h in ldsodefs.h, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 25/34] hurd: Improve reply port handling when exiting signal handlers, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 22/34] htl: Implement thread_set_pcsptp for x86_64, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 29/34] hurd: Add vm_param.h for x86_64, Sergey Bugaev, 2023/03/19
- [RFC PATCH glibc 31/34] hurd: Microoptimize _hurd_self_sigstate (), Sergey Bugaev, 2023/03/19