On 5/19/22 00:54, Huacai Chen wrote:
Hi, Eric,
On Thu, May 19, 2022 at 12:40 AM Eric W. Biederman
<ebiederm@xxxxxxxxxxxx> wrote:
Huacai Chen <chenhuacai@xxxxxxxxxxx> writes:
Add ucontext/sigcontext definition and signal handling support for
LoongArch.
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
arch/loongarch/include/uapi/asm/sigcontext.h | 44 ++
arch/loongarch/include/uapi/asm/signal.h | 13 +
arch/loongarch/include/uapi/asm/ucontext.h | 35 ++
arch/loongarch/kernel/signal.c | 566 +++++++++++++++++++
4 files changed, 658 insertions(+)
create mode 100644 arch/loongarch/include/uapi/asm/sigcontext.h
create mode 100644 arch/loongarch/include/uapi/asm/signal.h
create mode 100644 arch/loongarch/include/uapi/asm/ucontext.h
create mode 100644 arch/loongarch/kernel/signal.c
diff --git a/arch/loongarch/include/uapi/asm/sigcontext.h b/arch/loongarch/include/uapi/asm/sigcontext.h
new file mode 100644
index 000000000000..be3d3c6ac83e
--- /dev/null
+++ b/arch/loongarch/include/uapi/asm/sigcontext.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Author: Hanlu Li <lihanlu@xxxxxxxxxxx>
+ * Huacai Chen <chenhuacai@xxxxxxxxxxx>
+ *
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _UAPI_ASM_SIGCONTEXT_H
+#define _UAPI_ASM_SIGCONTEXT_H
+
+#include <linux/types.h>
+#include <linux/posix_types.h>
+
+/* FP context was used */
+#define SC_USED_FP (1 << 0)
+/* Address error was due to memory load */
+#define SC_ADDRERR_RD (1 << 30)
+/* Address error was due to memory store */
+#define SC_ADDRERR_WR (1 << 31)
+
+struct sigcontext {
+ __u64 sc_pc;
+ __u64 sc_regs[32];
+ __u32 sc_flags;
+ __u64 sc_extcontext[0] __attribute__((__aligned__(16)));
+};
+
+#define CONTEXT_INFO_ALIGN 16
+struct _ctxinfo {
+ __u32 magic;
+ __u32 size;
+ __u64 padding; /* padding to 16 bytes */
+};
This is probably something I a missing but what is struct _ctxinfo and
why is it in a uapi header?
I don't see anything else in the uapi implementation using it.
This is used by get_ctx_through_ctxinfo() in signal.c and I think
similar function is also needed by userspace.
Its name is once before called context_info but conflict with another
software, then I want to use ctx_info but conflict with another kernel
struct. :(
Symbols that start with an underscore "_" are reserved and should not
be used in general, and especially not in uapi header files.
Then, maybe we can use sctx_info here?
Actually it seems to me that this struct is the header of each
sc_extcontext; i.e. one struct sigcontext with 0~N trailing
"sc_extcontext", and each "sc_extcontext" consists of one "struct
_ctxinfo" header plus the real content. For now there's only the FPU
context but the LSX/LASX/LBT contexts will come later. The "magic" and
"size" fields also matches the definitions following.
So I'd suggest something like "struct sc_extcontext_head" while naming
the individual contexts like "struct sc_extcontext_foo", e.g. "struct
sc_extcontext_fpu". The "sc_extcontext" part could use some further
abbreviation but the end result should be something intuitive.
Huacai
Eric
