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[PATCH v4.5 25/29] gdbstub: split out softmmu/user specifics for syscall
From: |
Richard Henderson |
Subject: |
[PATCH v4.5 25/29] gdbstub: split out softmmu/user specifics for syscall handling |
Date: |
Thu, 2 Mar 2023 18:58:01 -0800 |
From: Alex Bennée <alex.bennee@linaro.org>
Most of the syscall code is config agnostic aside from the size of
target_ulong. In preparation for the next patch move the final bits
of specialisation into the appropriate user and softmmu helpers.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230302190846.2593720-26-alex.bennee@linaro.org>
---
gdbstub/internals.h | 3 +++
gdbstub/softmmu.c | 14 ++++++++++++++
gdbstub/syscalls.c | 27 +++------------------------
gdbstub/user.c | 14 ++++++++++++++
4 files changed, 34 insertions(+), 24 deletions(-)
diff --git a/gdbstub/internals.h b/gdbstub/internals.h
index 8db61f7fb4..94ddff4495 100644
--- a/gdbstub/internals.h
+++ b/gdbstub/internals.h
@@ -195,6 +195,9 @@ bool gdb_handled_syscall(void);
void gdb_disable_syscalls(void);
void gdb_syscall_reset(void);
+/* user/softmmu specific syscall handling */
+void gdb_syscall_handling(const char *syscall_packet);
+
/*
* Break/Watch point support - there is an implementation for softmmu
* and user mode.
diff --git a/gdbstub/softmmu.c b/gdbstub/softmmu.c
index d3152fb6e7..22ecd09d04 100644
--- a/gdbstub/softmmu.c
+++ b/gdbstub/softmmu.c
@@ -103,6 +103,20 @@ static void gdb_chr_event(void *opaque, QEMUChrEvent event)
}
}
+/*
+ * In softmmu mode we stop the VM and wait to send the syscall packet
+ * until notification that the CPU has stopped. This must be done
+ * because if the packet is sent now the reply from the syscall
+ * request could be received while the CPU is still in the running
+ * state, which can cause packets to be dropped and state transition
+ * 'T' packets to be sent while the syscall is still being processed.
+ */
+void gdb_syscall_handling(const char *syscall_packet)
+{
+ vm_stop(RUN_STATE_DEBUG);
+ qemu_cpu_kick(gdbserver_state.c_cpu);
+}
+
static void gdb_vm_state_change(void *opaque, bool running, RunState state)
{
CPUState *cpu = gdbserver_state.c_cpu;
diff --git a/gdbstub/syscalls.c b/gdbstub/syscalls.c
index f15b210958..0a48f58d70 100644
--- a/gdbstub/syscalls.c
+++ b/gdbstub/syscalls.c
@@ -104,9 +104,7 @@ void gdb_do_syscallv(gdb_syscall_complete_cb cb, const char
*fmt, va_list va)
}
gdbserver_syscall_state.current_syscall_cb = cb;
-#ifndef CONFIG_USER_ONLY
- vm_stop(RUN_STATE_DEBUG);
-#endif
+
p = &gdbserver_syscall_state.syscall_buf[0];
p_end =
&gdbserver_syscall_state.syscall_buf[sizeof(gdbserver_syscall_state.syscall_buf)];
*(p++) = 'F';
@@ -141,27 +139,8 @@ void gdb_do_syscallv(gdb_syscall_complete_cb cb, const
char *fmt, va_list va)
}
}
*p = 0;
-#ifdef CONFIG_USER_ONLY
- gdb_put_packet(gdbserver_syscall_state.syscall_buf);
- /*
- * Return control to gdb for it to process the syscall request.
- * Since the protocol requires that gdb hands control back to us
- * using a "here are the results" F packet, we don't need to check
- * gdb_handlesig's return value (which is the signal to deliver if
- * execution was resumed via a continue packet).
- */
- gdb_handlesig(gdbserver_state.c_cpu, 0);
-#else
- /*
- * In this case wait to send the syscall packet until notification that
- * the CPU has stopped. This must be done because if the packet is sent
- * now the reply from the syscall request could be received while the CPU
- * is still in the running state, which can cause packets to be dropped
- * and state transition 'T' packets to be sent while the syscall is still
- * being processed.
- */
- qemu_cpu_kick(gdbserver_state.c_cpu);
-#endif
+
+ gdb_syscall_handling(gdbserver_syscall_state.syscall_buf);
}
void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
diff --git a/gdbstub/user.c b/gdbstub/user.c
index 3da410e221..80488b6bb9 100644
--- a/gdbstub/user.c
+++ b/gdbstub/user.c
@@ -472,3 +472,17 @@ void gdb_breakpoint_remove_all(CPUState *cs)
{
cpu_breakpoint_remove_all(cs, BP_GDB);
}
+
+/*
+ * For user-mode syscall support we send the system call immediately
+ * and then return control to gdb for it to process the syscall request.
+ * Since the protocol requires that gdb hands control back to us
+ * using a "here are the results" F packet, we don't need to check
+ * gdb_handlesig's return value (which is the signal to deliver if
+ * execution was resumed via a continue packet).
+ */
+void gdb_syscall_handling(const char *syscall_packet)
+{
+ gdb_put_packet(syscall_packet);
+ gdb_handlesig(gdbserver_state.c_cpu, 0);
+}
--
2.34.1
- [PATCH v4.5 13/29] gdbstub: abstract target specific details from gdb_put_packet_binary, (continued)
- [PATCH v4.5 13/29] gdbstub: abstract target specific details from gdb_put_packet_binary, Richard Henderson, 2023/03/02
- [PATCH v4.5 14/29] gdbstub: specialise handle_query_attached, Richard Henderson, 2023/03/02
- [PATCH v4.5 15/29] gdbstub: specialise target_memory_rw_debug, Richard Henderson, 2023/03/02
- [PATCH v4.5 07/29] includes: move tb_flush into its own header, Richard Henderson, 2023/03/02
- [PATCH v4.5 17/29] gdbstub: specialise stub_can_reverse, Richard Henderson, 2023/03/02
- [PATCH v4.5 19/29] gdbstub: don't use target_ulong while handling registers, Richard Henderson, 2023/03/02
- [PATCH v4.5 18/29] gdbstub: fix address type of gdb_set_cpu_pc, Richard Henderson, 2023/03/02
- [PATCH v4.5 20/29] gdbstub: move register helpers into standalone include, Richard Henderson, 2023/03/02
- [PATCH v4.5 22/29] gdbstub: only compile gdbstub twice for whole build, Richard Henderson, 2023/03/02
- [PATCH v4.5 21/29] gdbstub: move syscall handling to new file, Richard Henderson, 2023/03/02
- [PATCH v4.5 25/29] gdbstub: split out softmmu/user specifics for syscall handling,
Richard Henderson <=
- [PATCH v4.5 27/29] gdbstub: Adjust gdb_do_syscall to only use uint32_t and uint64_t, Richard Henderson, 2023/03/02
- [PATCH v4.5 24/29] include: split target_long definition from cpu-defs, Richard Henderson, 2023/03/02
- [PATCH v4.5 23/29] testing: probe gdb for supported architectures ahead of time, Richard Henderson, 2023/03/02
- [PATCH v4.5 26/29] gdbstub: Remove gdb_do_syscallv, Richard Henderson, 2023/03/02
- [PATCH v4.5 29/29] gdbstub: move update guest debug to accel ops, Richard Henderson, 2023/03/02
- [PATCH v4.5 28/29] gdbstub: Build syscall.c once, Richard Henderson, 2023/03/02