[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Minios-devel] [UNIKRAFT PATCH 3/4] plat: switch thread-local storage area on context switch
Hi Costin,
On 4/16/19 3:22 PM, Costin Lupu wrote:
Hi Florian,
Please see my comments inline.
On 4/15/19 1:03 PM, Florian Schmidt wrote:
On x86, the standard way is writing to an MSR to switch the fs register,
which is used as the pointer to the TLS area. However, this is a
privileged instruction, so for the linuxu platform, use a system call
provided by Linux that does exactly that instead.
Signed-off-by: Florian Schmidt <florian.schmidt@xxxxxxxxx>
---
arch/x86/x86_64/include/uk/asm/thread.h | 5 +++
include/uk/plat/thread.h | 8 ++--
lib/uksched/thread.c | 5 ++-
plat/common/include/sw_ctx.h | 1 +
plat/common/include/thread_switch.h | 43 +++++++++++++++++++
plat/common/include/x86/thread_switch.h | 41 ++++++++++++++++++
plat/common/sw_ctx.c | 10 ++++-
plat/linuxu/include/linuxu/syscall-x86_64.h | 1 +
plat/linuxu/include/linuxu/syscall.h | 7 ++++
plat/linuxu/include/thread_switch.h | 46 +++++++++++++++++++++
10 files changed, 160 insertions(+), 7 deletions(-)
create mode 100644 plat/common/include/thread_switch.h
create mode 100644 plat/common/include/x86/thread_switch.h
create mode 100644 plat/linuxu/include/thread_switch.h
diff --git a/arch/x86/x86_64/include/uk/asm/thread.h
b/arch/x86/x86_64/include/uk/asm/thread.h
index 6e95848d..f07eb521 100644
--- a/arch/x86/x86_64/include/uk/asm/thread.h
+++ b/arch/x86/x86_64/include/uk/asm/thread.h
@@ -62,3 +62,8 @@ static inline void tls_copy(void *tls_area)
memset(tls_area+tls_data_len, 0, tls_bss_len);
*((uintptr_t *)(tls_area+tls_len)) = (uintptr_t)(tls_area+tls_len);
}
+
+static inline void *tls_pointer(void *tls_area)
+{
+ return tls_area + (_tls_end - _tls_start);
+}
diff --git a/include/uk/plat/thread.h b/include/uk/plat/thread.h
index 69fc5e28..4b349ea7 100644
--- a/include/uk/plat/thread.h
+++ b/include/uk/plat/thread.h
@@ -51,7 +51,8 @@ enum ukplat_ctx_type {
struct uk_alloc;
typedef void *(*ukplat_ctx_create_func_t)
- (struct uk_alloc *allocator, unsigned long sp);
+ (struct uk_alloc *allocator, unsigned long sp,
+ unsigned long tlsp);
typedef void (*ukplat_ctx_start_func_t)
(void *ctx);
typedef void (*ukplat_ctx_switch_func_t)
@@ -72,12 +73,13 @@ int ukplat_ctx_callbacks_init(struct ukplat_ctx_callbacks
*ctx_cbs,
static inline
void *ukplat_thread_ctx_create(struct ukplat_ctx_callbacks *cbs,
- struct uk_alloc *allocator, unsigned long sp)
+ struct uk_alloc *allocator, unsigned long sp,
+ unsigned long tlsp)
{
UK_ASSERT(cbs != NULL);
UK_ASSERT(allocator != NULL);
- return cbs->create_cb(allocator, sp);
+ return cbs->create_cb(allocator, sp, tlsp);
}
void ukplat_thread_ctx_destroy(struct uk_alloc *allocator, void *ctx);
diff --git a/lib/uksched/thread.c b/lib/uksched/thread.c
index a97fad9e..45f79206 100644
--- a/lib/uksched/thread.c
+++ b/lib/uksched/thread.c
@@ -39,7 +39,7 @@
#include <uk/wait.h>
#include <uk/print.h>
#include <uk/assert.h>
-
+#include <uk/arch/thread.h>
/* Pushes the specified value onto the stack of the specified thread */
static void stack_push(unsigned long *sp, unsigned long value)
@@ -103,7 +103,8 @@ int uk_thread_init(struct uk_thread *thread,
init_sp(&sp, stack, function, arg);
/* Call platform specific setup. */
- thread->ctx = ukplat_thread_ctx_create(cbs, allocator, sp);
+ thread->ctx = ukplat_thread_ctx_create(cbs, allocator, sp,
+ (uintptr_t)tls_pointer(tls));
if (thread->ctx == NULL)
return -1;
diff --git a/plat/common/include/sw_ctx.h b/plat/common/include/sw_ctx.h
index d52fe65b..366c6a8f 100644
--- a/plat/common/include/sw_ctx.h
+++ b/plat/common/include/sw_ctx.h
@@ -41,6 +41,7 @@
struct sw_ctx {
unsigned long sp; /* Stack pointer */
unsigned long ip; /* Instruction pointer */
+ unsigned long tlsp; /* thread-local storage pointer */
uintptr_t extregs; /* Pointer to an area to which extended
* registers are saved on context switch.
*/
diff --git a/plat/common/include/thread_switch.h
b/plat/common/include/thread_switch.h
new file mode 100644
index 00000000..b04c38c5
--- /dev/null
+++ b/plat/common/include/thread_switch.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Florian Schmidt <florian.schmidt@xxxxxxxxx>
+ *
+ * Copyright (c) 2019, NEC Europe Ltd., NEC Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+#ifndef __PLAT_CMN_THREAD_SWITCH_H__
+#define __PLAT_CMN_THREAD_SWITCH_H__
+
+#if defined(__X86_64__)
+#include <x86/thread_switch.h>
+#else
+#error "Add thread_switch.h for current architecture."
+#endif
+
+#endif /* __PLAT_CMN_THREAD_SWITCH_H__ */
diff --git a/plat/common/include/x86/thread_switch.h
b/plat/common/include/x86/thread_switch.h
new file mode 100644
index 00000000..f8252916
--- /dev/null
+++ b/plat/common/include/x86/thread_switch.h
For this file the location is correct, according to my comments for the
previous patch. However, I would use the same header for both sets of
changes and rename it to tls.h .
I'll make it consistent with the file in the previous patch.
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Florian Schmidt <florian.schmidt@xxxxxxxxx>
+ *
+ * Copyright (c) 2019, NEC Europe Ltd., NEC Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+#ifndef __PLAT_CMN_X86_THREAD_SWITCH_H__
+#define __PLAT_CMN_X86_THREAD_SWITCH_H__
+
+#define MSR_FS_BASE 0xc0000100
This is a CPU related macro, please move it to
plat/common/include/x86/cpu_defs.h where all the CPU related macros are
defined.
OK, I'll do that (and maybe change the name according to the scheme in
that file).
+
+#define set_tls_pointer(ptr) wrmsrl(MSR_FS_BASE, ptr)
+
+#endif /* __PLAT_CMN_X86_THREAD_SWITCH_H__ */
diff --git a/plat/common/sw_ctx.c b/plat/common/sw_ctx.c
index 06795244..088d1233 100644
--- a/plat/common/sw_ctx.c
+++ b/plat/common/sw_ctx.c
@@ -39,9 +39,11 @@
#include <uk/alloc.h>
#include <sw_ctx.h>
#include <uk/assert.h>
+#include <thread_switch.h>
#include <x86/cpu.h>
-static void *sw_ctx_create(struct uk_alloc *allocator, unsigned long sp);
+static void *sw_ctx_create(struct uk_alloc *allocator, unsigned long sp,
+ unsigned long tlsp);
static void sw_ctx_start(void *ctx) __noreturn;
static void sw_ctx_switch(void *prevctx, void *nextctx);
@@ -51,7 +53,8 @@ static void sw_ctx_switch(void *prevctx, void *nextctx);
*/
extern void asm_thread_starter(void);
-static void *sw_ctx_create(struct uk_alloc *allocator, unsigned long sp)
+static void *sw_ctx_create(struct uk_alloc *allocator, unsigned long sp,
+ unsigned long tlsp)
{
struct sw_ctx *ctx;
size_t sz;
@@ -68,6 +71,7 @@ static void *sw_ctx_create(struct uk_alloc *allocator,
unsigned long sp)
}
ctx->sp = sp;
+ ctx->tlsp = tlsp;
ctx->ip = (unsigned long) asm_thread_starter;
ctx->extregs = ALIGN_UP(((uintptr_t)ctx + sizeof(struct sw_ctx)),
x86_cpu_features.extregs_align);
@@ -86,6 +90,7 @@ static void sw_ctx_start(void *ctx)
UK_ASSERT(sw_ctx != NULL);
+ set_tls_pointer(sw_ctx->tlsp);
/* Switch stacks and run the thread */
asm_ctx_start(sw_ctx->sp, sw_ctx->ip);
@@ -101,6 +106,7 @@ static void sw_ctx_switch(void *prevctx, void *nextctx)
save_extregs(p);
restore_extregs(n);
+ set_tls_pointer(n->tlsp);
asm_sw_ctx_switch(prevctx, nextctx);
}
diff --git a/plat/linuxu/include/linuxu/syscall-x86_64.h b/plat/linuxu/include/linuxu/syscall-x86_64.h
index 26820dcd..553f0ba4 100644
--- a/plat/linuxu/include/linuxu/syscall-x86_64.h
+++ b/plat/linuxu/include/linuxu/syscall-x86_64.h
@@ -48,6 +48,7 @@
#define __SC_RT_SIGPROCMASK 14
#define __SC_IOCTL 16
#define __SC_EXIT 60
+#define __SC_ARCH_PRCTL 158
#define __SC_TIMER_CREATE 222
#define __SC_TIMER_SETTIME 223
#define __SC_TIMER_GETTIME 224
diff --git a/plat/linuxu/include/linuxu/syscall.h
b/plat/linuxu/include/linuxu/syscall.h
index d378d265..d5b66698 100644
--- a/plat/linuxu/include/linuxu/syscall.h
+++ b/plat/linuxu/include/linuxu/syscall.h
@@ -123,6 +123,13 @@ static inline int sys_sigprocmask(int how,
sizeof(k_sigset_t));
}
+static inline int sys_arch_prctl(int code, unsigned long addr)
+{
+ return (int) syscall2(__SC_ARCH_PRCTL,
+ (long) code,
+ (long) addr);
+}
+
static inline int sys_pselect6(int nfds,
k_fd_set *readfds, k_fd_set *writefds, k_fd_set *exceptfds,
const struct k_timespec *timeout, const void *sigmask)
diff --git a/plat/linuxu/include/thread_switch.h
b/plat/linuxu/include/thread_switch.h
new file mode 100644
index 00000000..3a0f962f
--- /dev/null
+++ b/plat/linuxu/include/thread_switch.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Florian Schmidt <florian.schmidt@xxxxxxxxx>
+ *
+ * Copyright (c) 2019, NEC Europe Ltd., NEC Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+#ifndef __PLAT_THREAD_SWITCH_H__
+#define __PLAT_THREAD_SWITCH_H__
+
+#include <linuxu/syscall.h>
+
+#define ARCH_SET_FS 0x1002
+
+static inline void set_tls_pointer(unsigned long arg)
+{
+ sys_arch_prctl(ARCH_SET_FS, arg);
+}
+
+#endif /* __PLAT_THREAD_SWITCH_H__ */
--
Dr. Florian Schmidt
フローリアン・シュミット
Research Scientist,
Systems and Machine Learning Group
NEC Laboratories Europe
Kurfürsten-Anlage 36, D-69115 Heidelberg
Tel. +49 (0)6221 4342-265
Fax: +49 (0)6221 4342-155
e-mail: florian.schmidt@xxxxxxxxx
============================================================
Registered at Amtsgericht Mannheim, Germany, HRB728558
_______________________________________________
Minios-devel mailing list
Minios-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/minios-devel
|
