From 914c30863b45d6fcd3e2fc83929bcac546be1555 Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Thu, 5 Nov 2020 15:48:24 +0100
Subject: [PATCH] linux-user: Correct definition of stack_t

Some platforms used the wrong definition of stack_t where the flags and
size fields were swapped or where the flags field had type ulong instead
of int.

Due to the presence of padding space in the structure and the prevalence
of little-endian machines this problem went unnoticed for a long time.

The type definitions have been cross-checked with the ones defined in
the Linux kernel v5.9, plus some older versions for a few architecture
that have been removed and Xilinx's kernel fork for NiosII [1].

The microblaze header and the bsd-user ones remain unchanged as I don't
know if they are wrong or not.

[1] https://github.com/Xilinx/linux-xlnx/blob/master/arch/nios2/include/uapi/asm/signal.h

Signed-off-by: Giuseppe Musacchio <thatlemon@gmail.com>
---
 linux-user/alpha/target_signal.h  | 3 +--
 linux-user/arm/target_signal.h    | 6 +++---
 linux-user/cris/target_signal.h   | 6 +++---
 linux-user/hppa/target_signal.h   | 2 +-
 linux-user/i386/target_signal.h   | 6 +++---
 linux-user/m68k/target_signal.h   | 6 +++---
 linux-user/mips/target_signal.h   | 6 +++---
 linux-user/mips64/target_signal.h | 7 +++----
 linux-user/nios2/target_signal.h  | 5 +++--
 linux-user/ppc/target_signal.h    | 6 +++---
 linux-user/s390x/target_signal.h  | 2 +-
 linux-user/sh4/target_signal.h    | 6 +++---
 linux-user/sparc/target_signal.h  | 6 +++---
 linux-user/x86_64/target_signal.h | 6 +++---
 14 files changed, 36 insertions(+), 37 deletions(-)

diff --git a/linux-user/alpha/target_signal.h b/linux-user/alpha/target_signal.h
index cd63d59fde..b83797281c 100644
--- a/linux-user/alpha/target_signal.h
+++ b/linux-user/alpha/target_signal.h
@@ -42,8 +42,7 @@
 
 typedef struct target_sigaltstack {
     abi_ulong ss_sp;
-    int32_t ss_flags;
-    int32_t dummy;
+    abi_int ss_flags;
     abi_ulong ss_size;
 } target_stack_t;
 
diff --git a/linux-user/arm/target_signal.h b/linux-user/arm/target_signal.h
index ea123c40f3..0998dd6dfa 100644
--- a/linux-user/arm/target_signal.h
+++ b/linux-user/arm/target_signal.h
@@ -4,9 +4,9 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-	abi_ulong ss_sp;
-	abi_long ss_flags;
-	abi_ulong ss_size;
+    abi_ulong ss_sp;
+    abi_int ss_flags;
+    abi_ulong ss_size;
 } target_stack_t;
 
 
diff --git a/linux-user/cris/target_signal.h b/linux-user/cris/target_signal.h
index 1cb5548f85..495a142896 100644
--- a/linux-user/cris/target_signal.h
+++ b/linux-user/cris/target_signal.h
@@ -4,9 +4,9 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-	abi_ulong ss_sp;
-	abi_ulong ss_size;
-	abi_long ss_flags;
+    abi_ulong ss_sp;
+    abi_int ss_flags;
+    abi_ulong ss_size;
 } target_stack_t;
 
 
diff --git a/linux-user/hppa/target_signal.h b/linux-user/hppa/target_signal.h
index c2a0102ed7..c52a3ea579 100644
--- a/linux-user/hppa/target_signal.h
+++ b/linux-user/hppa/target_signal.h
@@ -44,7 +44,7 @@
 
 typedef struct target_sigaltstack {
     abi_ulong ss_sp;
-    int32_t ss_flags;
+    abi_int ss_flags;
     abi_ulong ss_size;
 } target_stack_t;
 
diff --git a/linux-user/i386/target_signal.h b/linux-user/i386/target_signal.h
index f55e78fd33..50361af874 100644
--- a/linux-user/i386/target_signal.h
+++ b/linux-user/i386/target_signal.h
@@ -4,9 +4,9 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-	abi_ulong ss_sp;
-	abi_long ss_flags;
-	abi_ulong ss_size;
+    abi_ulong ss_sp;
+    abi_int ss_flags;
+    abi_ulong ss_size;
 } target_stack_t;
 
 
diff --git a/linux-user/m68k/target_signal.h b/linux-user/m68k/target_signal.h
index 314e808844..d096544ef8 100644
--- a/linux-user/m68k/target_signal.h
+++ b/linux-user/m68k/target_signal.h
@@ -4,9 +4,9 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-	abi_ulong ss_sp;
-	abi_long ss_flags;
-	abi_ulong ss_size;
+    abi_ulong ss_sp;
+    abi_int ss_flags;
+    abi_ulong ss_size;
 } target_stack_t;
 
 
diff --git a/linux-user/mips/target_signal.h b/linux-user/mips/target_signal.h
index 66e1ad44a6..fa4084a99d 100644
--- a/linux-user/mips/target_signal.h
+++ b/linux-user/mips/target_signal.h
@@ -45,9 +45,9 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-	abi_long ss_sp;
-	abi_ulong ss_size;
-	abi_long ss_flags;
+    abi_ulong ss_sp;
+    abi_ulong ss_size;
+    abi_int ss_flags;
 } target_stack_t;
 
 
diff --git a/linux-user/mips64/target_signal.h b/linux-user/mips64/target_signal.h
index 753e91fbd6..799f7a668c 100644
--- a/linux-user/mips64/target_signal.h
+++ b/linux-user/mips64/target_signal.h
@@ -45,12 +45,11 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-	abi_long ss_sp;
-	abi_ulong ss_size;
-	abi_int ss_flags;
+    abi_ulong ss_sp;
+    abi_ulong ss_size;
+    abi_int ss_flags;
 } target_stack_t;
 
-
 /*
  * sigaltstack controls
  */
diff --git a/linux-user/nios2/target_signal.h b/linux-user/nios2/target_signal.h
index fe48721b3d..aebf749f12 100644
--- a/linux-user/nios2/target_signal.h
+++ b/linux-user/nios2/target_signal.h
@@ -4,11 +4,12 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-    abi_long ss_sp;
+    abi_ulong ss_sp;
+    abi_int ss_flags;
     abi_ulong ss_size;
-    abi_long ss_flags;
 } target_stack_t;
 
+
 /* sigaltstack controls  */
 #define TARGET_SS_ONSTACK     1
 #define TARGET_SS_DISABLE     2
diff --git a/linux-user/ppc/target_signal.h b/linux-user/ppc/target_signal.h
index 4453e2e7ef..72fcdd9bfa 100644
--- a/linux-user/ppc/target_signal.h
+++ b/linux-user/ppc/target_signal.h
@@ -4,9 +4,9 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-	abi_ulong ss_sp;
-	int ss_flags;
-	abi_ulong ss_size;
+    abi_ulong ss_sp;
+    abi_int ss_flags;
+    abi_ulong ss_size;
 } target_stack_t;
 
 
diff --git a/linux-user/s390x/target_signal.h b/linux-user/s390x/target_signal.h
index b58bc7c20f..bbfc464d44 100644
--- a/linux-user/s390x/target_signal.h
+++ b/linux-user/s390x/target_signal.h
@@ -3,7 +3,7 @@
 
 typedef struct target_sigaltstack {
     abi_ulong ss_sp;
-    int ss_flags;
+    abi_int ss_flags;
     abi_ulong ss_size;
 } target_stack_t;
 
diff --git a/linux-user/sh4/target_signal.h b/linux-user/sh4/target_signal.h
index 434970a990..d7309b7136 100644
--- a/linux-user/sh4/target_signal.h
+++ b/linux-user/sh4/target_signal.h
@@ -4,9 +4,9 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-	abi_ulong ss_sp;
-	abi_long ss_flags;
-	abi_ulong ss_size;
+    abi_ulong ss_sp;
+    abi_int ss_flags;
+    abi_ulong ss_size;
 } target_stack_t;
 
 
diff --git a/linux-user/sparc/target_signal.h b/linux-user/sparc/target_signal.h
index 5cc40327d2..1b10d1490f 100644
--- a/linux-user/sparc/target_signal.h
+++ b/linux-user/sparc/target_signal.h
@@ -42,9 +42,9 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-	abi_ulong ss_sp;
-	abi_long ss_flags;
-	abi_ulong ss_size;
+    abi_ulong ss_sp;
+    abi_int ss_flags;
+    abi_ulong ss_size;
 } target_stack_t;
 
 
diff --git a/linux-user/x86_64/target_signal.h b/linux-user/x86_64/target_signal.h
index 4c4380f7b9..4ea74f20dd 100644
--- a/linux-user/x86_64/target_signal.h
+++ b/linux-user/x86_64/target_signal.h
@@ -4,9 +4,9 @@
 /* this struct defines a stack used during syscall handling */
 
 typedef struct target_sigaltstack {
-	abi_ulong ss_sp;
-	abi_long ss_flags;
-	abi_ulong ss_size;
+    abi_ulong ss_sp;
+    abi_int ss_flags;
+    abi_ulong ss_size;
 } target_stack_t;
 
 
-- 
2.27.0

On Thu, 5 Nov 2020 at 14:55, LemonBoy <thatlemon@gmail.com> wrote:
>
> From 914c30863b45d6fcd3e2fc83929bcac546be1555 Mon Sep 17 00:00:00 2001
> From: LemonBoy <thatlemon@gmail.com>
> Date: Thu, 5 Nov 2020 15:48:24 +0100
> Subject: [PATCH] linux-user: Correct definition of stack_t
>
> Some platforms used the wrong definition of stack_t where the flags and
> size fields were swapped or where the flags field had type ulong instead
> of int.

Coincidentally, I just noticed this yesterday (am in the middle of
trying to debug why qemu-sparc64 crashes trying to start bash...)

> Due to the presence of padding space in the structure and the prevalence
> of little-endian machines this problem went unnoticed for a long time.
>
> The type definitions have been cross-checked with the ones defined in
> the Linux kernel v5.9, plus some older versions for a few architecture
> that have been removed and Xilinx's kernel fork for NiosII [1].
>
> The microblaze header and the bsd-user ones remain unchanged as I don't
> know if they are wrong or not.

As far as I can tell, Microblaze doesn't define its own stack_t,
so it must be using the asm-generic one,  so I think it also needs
changing.

> [1] https://github.com/Xilinx/linux-xlnx/blob/master/arch/nios2/include/uapi/asm/signal.h

> Signed-off-by: Giuseppe Musacchio <thatlemon@gmail.com>

Other than also changing microblaze,
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

On 05/11/20 16:16, Peter Maydell wrote:
> On Thu, 5 Nov 2020 at 14:55, LemonBoy <thatlemon@gmail.com> wrote:
>>
>> From 914c30863b45d6fcd3e2fc83929bcac546be1555 Mon Sep 17 00:00:00 2001
>> From: LemonBoy <thatlemon@gmail.com>
>> Date: Thu, 5 Nov 2020 15:48:24 +0100
>> Subject: [PATCH] linux-user: Correct definition of stack_t
>>
>> Some platforms used the wrong definition of stack_t where the flags and
>> size fields were swapped or where the flags field had type ulong instead
>> of int.
> 
> Coincidentally, I just noticed this yesterday (am in the middle of
> trying to debug why qemu-sparc64 crashes trying to start bash...)
> 

What an interesting coincidence, I also stumbled across this bug while
debugging a crash with some sparc64 binary.

>> Due to the presence of padding space in the structure and the prevalence
>> of little-endian machines this problem went unnoticed for a long time.
>>
>> The type definitions have been cross-checked with the ones defined in
>> the Linux kernel v5.9, plus some older versions for a few architecture
>> that have been removed and Xilinx's kernel fork for NiosII [1].
>>
>> The microblaze header and the bsd-user ones remain unchanged as I don't
>> know if they are wrong or not.
> 
> As far as I can tell, Microblaze doesn't define its own stack_t,
> so it must be using the asm-generic one,  so I think it also needs
> changing.
> 

I'll change it and send an updated patch ASAP.

>> [1] https://github.com/Xilinx/linux-xlnx/blob/master/arch/nios2/include/uapi/asm/signal.h
> 
>> Signed-off-by: Giuseppe Musacchio <thatlemon@gmail.com>
> 
> Other than also changing microblaze,
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> 
> thanks
> -- PMM
> 

On Thu, 5 Nov 2020 at 15:48, LemonBoy <thatlemon@gmail.com> wrote:
> On 05/11/20 16:16, Peter Maydell wrote:
> > Coincidentally, I just noticed this yesterday (am in the middle of
> > trying to debug why qemu-sparc64 crashes trying to start bash...)
> >
>
> What an interesting coincidence, I also stumbled across this bug while
> debugging a crash with some sparc64 binary.

Don't suppose it involves sigsetjmp/siglongjmp?
So far I have discovered that the linux-user/sparc
target_ucontext and friends have host pointers where
they should have abi_ulong and also that target_mc_fpu
needs explicit 16-alignment (patch written, will post it
sometime this week), and once past that have hit another
bug that seems to be down to the setcontext/getcontext
traps not saving and restoring all the right registers.

thanks
-- PMM