Re: [PATCH v6 18/19] linux-user/s390x: Add vdso

2023-10-06 Thread Thomas Huth 

On 05/10/2023 18.14, Philippe Mathieu-Daudé wrote:

On 4/10/23 01:01, Richard Henderson wrote:

On 10/3/23 06:07, Philippe Mathieu-Daudé wrote:

+++ b/linux-user/s390x/vdso.ld
@@ -0,0 +1,69 @@
+/*
+ * Linker script for linux x86-64 replacement vdso.


Should that be s390x instead of x86-64 ?


+ * Copyright 2023 Linaro, Ltd.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+VERSION {
+    LINUX_2.6.29 {
+    global:
+    __kernel_gettimeofday;
+    __kernel_clock_gettime;
+    __kernel_clock_getres;
+    __kernel_getcpu;
+    __kernel_restart_syscall;


Where is __kernel_restart_syscall defined?


It isn't, and I guess isn't needed for qemu (we have QEMU_ERESTARTSYS).
I'm not sure why it's an exported symbol for the s390x vdso for the 
kernel, even if they do require some user-space code.


Anyway, I'll remove the symbol here.


OK.

I dare to give:

Reviewed-by: Philippe Mathieu-Daudé 

But still I'm Cc'ing David / Thomas who better know s390x :)


Uh, oh, vdso ... I remember some dark magic here on the real kernels on 
s390x, involving access registers ... good that we don't need those here :-)


I quickly glanced through the code, and apart from the typo above, it looks 
good to me, so:


Acked-by: Thomas Huth

Re: [PATCH v6 18/19] linux-user/s390x: Add vdso

2023-10-05 Thread Philippe Mathieu-Daudé 

On 4/10/23 01:01, Richard Henderson wrote:

On 10/3/23 06:07, Philippe Mathieu-Daudé wrote:

+++ b/linux-user/s390x/vdso.ld
@@ -0,0 +1,69 @@
+/*
+ * Linker script for linux x86-64 replacement vdso.
+ *
+ * Copyright 2023 Linaro, Ltd.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+VERSION {
+    LINUX_2.6.29 {
+    global:
+    __kernel_gettimeofday;
+    __kernel_clock_gettime;
+    __kernel_clock_getres;
+    __kernel_getcpu;
+    __kernel_restart_syscall;


Where is __kernel_restart_syscall defined?


It isn't, and I guess isn't needed for qemu (we have QEMU_ERESTARTSYS).
I'm not sure why it's an exported symbol for the s390x vdso for the 
kernel, even if they do require some user-space code.


Anyway, I'll remove the symbol here.


OK.

I dare to give:

Reviewed-by: Philippe Mathieu-Daudé 

But still I'm Cc'ing David / Thomas who better know s390x :)

Re: [PATCH v6 18/19] linux-user/s390x: Add vdso

2023-10-03 Thread Richard Henderson 

On 10/3/23 06:07, Philippe Mathieu-Daudé wrote:

+++ b/linux-user/s390x/vdso.ld
@@ -0,0 +1,69 @@
+/*
+ * Linker script for linux x86-64 replacement vdso.
+ *
+ * Copyright 2023 Linaro, Ltd.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+VERSION {
+    LINUX_2.6.29 {
+    global:
+    __kernel_gettimeofday;
+    __kernel_clock_gettime;
+    __kernel_clock_getres;
+    __kernel_getcpu;
+    __kernel_restart_syscall;


Where is __kernel_restart_syscall defined?


It isn't, and I guess isn't needed for qemu (we have QEMU_ERESTARTSYS).
I'm not sure why it's an exported symbol for the s390x vdso for the kernel, even if they 
do require some user-space code.


Anyway, I'll remove the symbol here.


r~

Re: [PATCH v6 18/19] linux-user/s390x: Add vdso

2023-10-03 Thread Philippe Mathieu-Daudé 

Hi Richard,

On 30/9/23 04:15, Richard Henderson wrote:

Signed-off-by: Richard Henderson 
---
  linux-user/s390x/vdso-asmoffset.h |   2 +
  linux-user/elfload.c  |   2 +
  linux-user/s390x/signal.c |   4 +-
  linux-user/s390x/Makefile.vdso|  11 +
  linux-user/s390x/meson.build  |   6 +++
  linux-user/s390x/vdso.S   |  61 ++
  linux-user/s390x/vdso.ld  |  69 ++
  linux-user/s390x/vdso.so  | Bin 0 -> 3464 bytes
  8 files changed, 152 insertions(+), 3 deletions(-)
  create mode 100644 linux-user/s390x/vdso-asmoffset.h
  create mode 100644 linux-user/s390x/Makefile.vdso
  create mode 100644 linux-user/s390x/vdso.S
  create mode 100644 linux-user/s390x/vdso.ld
  create mode 100755 linux-user/s390x/vdso.so




diff --git a/linux-user/s390x/Makefile.vdso b/linux-user/s390x/Makefile.vdso
new file mode 100644
index 00..e82bf9e29f
--- /dev/null
+++ b/linux-user/s390x/Makefile.vdso
@@ -0,0 +1,11 @@
+include $(BUILD_DIR)/tests/tcg/s390x-linux-user/config-target.mak
+
+SUBDIR = $(SRC_PATH)/linux-user/s390x
+VPATH += $(SUBDIR)
+
+all: $(SUBDIR)/vdso.so
+
+$(SUBDIR)/vdso.so: vdso.S vdso.ld vdso-asmoffset.h
+   $(CC) -o $@ -nostdlib -shared -Wl,-h,linux-vdso64.so.1 \
+ -Wl,--build-id=sha1 -Wl,--hash-style=both \
+ -Wl,-T,$(SUBDIR)/vdso.ld $<
diff --git a/linux-user/s390x/meson.build b/linux-user/s390x/meson.build
index 0781ccea1d..a7a25ed9ce 100644
--- a/linux-user/s390x/meson.build
+++ b/linux-user/s390x/meson.build
@@ -3,3 +3,9 @@ syscall_nr_generators += {
   arguments: [ meson.current_source_dir() / 
'syscallhdr.sh', '@INPUT@', '@OUTPUT@', '@EXTRA_ARGS@' ],
   output: '@BASENAME@_nr.h')
  }
+
+vdso_inc = gen_vdso.process('vdso.so', extra_args: [
+'-s', '__kernel_sigreturn',
+'-r', '__kernel_rt_sigreturn'
+])
+linux_user_ss.add(when: 'TARGET_S390X', if_true: vdso_inc)
diff --git a/linux-user/s390x/vdso.S b/linux-user/s390x/vdso.S
new file mode 100644
index 00..3332492477
--- /dev/null
+++ b/linux-user/s390x/vdso.S
@@ -0,0 +1,61 @@
+/*
+ * s390x linux replacement vdso.
+ *
+ * Copyright 2023 Linaro, Ltd.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include 
+#include "vdso-asmoffset.h"
+
+.macro endf name
+   .globl  \name
+   .type   \name, @function
+   .size   \name, . - \name
+.endm
+
+.macro raw_syscall n
+.ifne  \n < 0x100
+   svc \n
+   .else
+   lghi%r1, \n
+   svc 0
+.endif
+.endm
+
+.macro vdso_syscall name, nr
+\name:
+   .cfi_startproc
+   aghi%r15, -(STACK_FRAME_OVERHEAD + 16)
+   .cfi_adjust_cfa_offset STACK_FRAME_OVERHEAD + 16
+   stg %r14, STACK_FRAME_OVERHEAD(%r15)
+   .cfi_rel_offset %r14, STACK_FRAME_OVERHEAD
+   raw_syscall \nr
+   lg  %r14, STACK_FRAME_OVERHEAD(%r15)
+   aghi%r15, STACK_FRAME_OVERHEAD + 16
+   .cfi_restore %r14
+   .cfi_adjust_cfa_offset -(STACK_FRAME_OVERHEAD + 16)
+   br  %r14
+   .cfi_endproc
+endf   \name
+.endm
+
+vdso_syscall __kernel_gettimeofday, __NR_gettimeofday
+vdso_syscall __kernel_clock_gettime, __NR_clock_gettime
+vdso_syscall __kernel_clock_getres, __NR_clock_getres
+vdso_syscall __kernel_getcpu, __NR_getcpu
+
+/*
+ * TODO unwind info, though we're ok without it.
+ * The kernel supplies bogus empty unwind info, and it is likely ignored
+ * by all users.  Without it we get the fallback signal frame handling.
+ */
+
+__kernel_sigreturn:
+   raw_syscall __NR_sigreturn
+endf   __kernel_sigreturn
+
+__kernel_rt_sigreturn:
+   raw_syscall __NR_rt_sigreturn
+endf   __kernel_rt_sigreturn
diff --git a/linux-user/s390x/vdso.ld b/linux-user/s390x/vdso.ld
new file mode 100644
index 00..2a30ff382a
--- /dev/null
+++ b/linux-user/s390x/vdso.ld
@@ -0,0 +1,69 @@
+/*
+ * Linker script for linux x86-64 replacement vdso.
+ *
+ * Copyright 2023 Linaro, Ltd.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+VERSION {
+LINUX_2.6.29 {
+global:
+__kernel_gettimeofday;
+__kernel_clock_gettime;
+__kernel_clock_getres;
+__kernel_getcpu;
+__kernel_restart_syscall;


Where is __kernel_restart_syscall defined?


+__kernel_rt_sigreturn;
+__kernel_sigreturn;
+local: *;
+};
+}

[PATCH v6 18/19] linux-user/s390x: Add vdso

2023-09-29 Thread Richard Henderson 
Signed-off-by: Richard Henderson 
---
 linux-user/s390x/vdso-asmoffset.h |   2 +
 linux-user/elfload.c  |   2 +
 linux-user/s390x/signal.c |   4 +-
 linux-user/s390x/Makefile.vdso|  11 +
 linux-user/s390x/meson.build  |   6 +++
 linux-user/s390x/vdso.S   |  61 ++
 linux-user/s390x/vdso.ld  |  69 ++
 linux-user/s390x/vdso.so  | Bin 0 -> 3464 bytes
 8 files changed, 152 insertions(+), 3 deletions(-)
 create mode 100644 linux-user/s390x/vdso-asmoffset.h
 create mode 100644 linux-user/s390x/Makefile.vdso
 create mode 100644 linux-user/s390x/vdso.S
 create mode 100644 linux-user/s390x/vdso.ld
 create mode 100755 linux-user/s390x/vdso.so

diff --git a/linux-user/s390x/vdso-asmoffset.h 
b/linux-user/s390x/vdso-asmoffset.h
new file mode 100644
index 00..27a062d6c1
--- /dev/null
+++ b/linux-user/s390x/vdso-asmoffset.h
@@ -0,0 +1,2 @@
+/* Minimum stack frame size */
+#define STACK_FRAME_OVERHEAD160
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 4a2d21a1f9..7450f9eab0 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1886,6 +1886,8 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs,
 #define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE 4096
 
+#define VDSO_HEADER "vdso.c.inc"
+
 #endif /* TARGET_S390X */
 
 #ifdef TARGET_RISCV
diff --git a/linux-user/s390x/signal.c b/linux-user/s390x/signal.c
index 0f8b8e04bf..b40f738a70 100644
--- a/linux-user/s390x/signal.c
+++ b/linux-user/s390x/signal.c
@@ -21,14 +21,12 @@
 #include "user-internals.h"
 #include "signal-common.h"
 #include "linux-user/trace.h"
+#include "vdso-asmoffset.h"
 
 #define __NUM_GPRS 16
 #define __NUM_FPRS 16
 #define __NUM_ACRS 16
 
-/* Minimum stack frame size */
-#define STACK_FRAME_OVERHEAD160
-
 #define _SIGCONTEXT_NSIG64
 #define _SIGCONTEXT_NSIG_BPW64 /* FIXME: 31-bit mode -> 32 */
 #define _SIGCONTEXT_NSIG_WORDS  (_SIGCONTEXT_NSIG / _SIGCONTEXT_NSIG_BPW)
diff --git a/linux-user/s390x/Makefile.vdso b/linux-user/s390x/Makefile.vdso
new file mode 100644
index 00..e82bf9e29f
--- /dev/null
+++ b/linux-user/s390x/Makefile.vdso
@@ -0,0 +1,11 @@
+include $(BUILD_DIR)/tests/tcg/s390x-linux-user/config-target.mak
+
+SUBDIR = $(SRC_PATH)/linux-user/s390x
+VPATH += $(SUBDIR)
+
+all: $(SUBDIR)/vdso.so
+
+$(SUBDIR)/vdso.so: vdso.S vdso.ld vdso-asmoffset.h
+   $(CC) -o $@ -nostdlib -shared -Wl,-h,linux-vdso64.so.1 \
+ -Wl,--build-id=sha1 -Wl,--hash-style=both \
+ -Wl,-T,$(SUBDIR)/vdso.ld $<
diff --git a/linux-user/s390x/meson.build b/linux-user/s390x/meson.build
index 0781ccea1d..a7a25ed9ce 100644
--- a/linux-user/s390x/meson.build
+++ b/linux-user/s390x/meson.build
@@ -3,3 +3,9 @@ syscall_nr_generators += {
  arguments: [ meson.current_source_dir() / 
'syscallhdr.sh', '@INPUT@', '@OUTPUT@', '@EXTRA_ARGS@' ],
  output: '@BASENAME@_nr.h')
 }
+
+vdso_inc = gen_vdso.process('vdso.so', extra_args: [
+'-s', '__kernel_sigreturn',
+'-r', '__kernel_rt_sigreturn'
+])
+linux_user_ss.add(when: 'TARGET_S390X', if_true: vdso_inc)
diff --git a/linux-user/s390x/vdso.S b/linux-user/s390x/vdso.S
new file mode 100644
index 00..3332492477
--- /dev/null
+++ b/linux-user/s390x/vdso.S
@@ -0,0 +1,61 @@
+/*
+ * s390x linux replacement vdso.
+ *
+ * Copyright 2023 Linaro, Ltd.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include 
+#include "vdso-asmoffset.h"
+
+.macro endf name
+   .globl  \name
+   .type   \name, @function
+   .size   \name, . - \name
+.endm
+
+.macro raw_syscall n
+.ifne  \n < 0x100
+   svc \n
+   .else
+   lghi%r1, \n
+   svc 0
+.endif
+.endm
+
+.macro vdso_syscall name, nr
+\name:
+   .cfi_startproc
+   aghi%r15, -(STACK_FRAME_OVERHEAD + 16)
+   .cfi_adjust_cfa_offset STACK_FRAME_OVERHEAD + 16
+   stg %r14, STACK_FRAME_OVERHEAD(%r15)
+   .cfi_rel_offset %r14, STACK_FRAME_OVERHEAD
+   raw_syscall \nr
+   lg  %r14, STACK_FRAME_OVERHEAD(%r15)
+   aghi%r15, STACK_FRAME_OVERHEAD + 16
+   .cfi_restore %r14
+   .cfi_adjust_cfa_offset -(STACK_FRAME_OVERHEAD + 16)
+   br  %r14
+   .cfi_endproc
+endf   \name
+.endm
+
+vdso_syscall __kernel_gettimeofday, __NR_gettimeofday
+vdso_syscall __kernel_clock_gettime, __NR_clock_gettime
+vdso_syscall __kernel_clock_getres, __NR_clock_getres
+vdso_syscall __kernel_getcpu, __NR_getcpu
+
+/*
+ * TODO unwind info, though we're ok without it.
+ * The kernel supplies bogus empty unwind info, and it is likely ignored
+ * by all users.  Without it we get the fallback signal frame handling.
+ */
+
+__kernel_sigreturn:
+   raw_syscall __NR_sigreturn
+endf   __kernel_sigreturn
+
+__kernel_rt_sigreturn:
+   raw_syscall __NR_rt_sigreturn
+endf   __kernel_rt_sigretur