[PATCH 0/3] mips{,64,n32}: Call exit on return from fn in __clone

[PATCH 0/3] mips{,64,n32}: Call exit on return from fn in __clone

[Segev Finer]

This is the expected behavior of this function.  Without this the child
task will crash on return from fn, since it will return to nowhere.

I only tested MIPS O32.

Segev Finer (3):
  mips: Call exit on return from fn in __clone
  mips64: Call exit on return from fn in __clone
  mipsn32: Call exit on return from fn in __clone

 src/thread/mips/clone.s    | 5 ++++-
 src/thread/mips64/clone.s  | 5 ++++-
 src/thread/mipsn32/clone.s | 5 ++++-
 3 files changed, 12 insertions(+), 3 deletions(-)

--
2.18.0

[PATCH 1/3] mips: Call exit on return from fn in __clone

[Segev Finer]

This is the expected behavior of this function.  Without this the child
task will crash on return from fn, since it will return to nowhere.
---
 src/thread/mips/clone.s | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/thread/mips/clone.s b/src/thread/mips/clone.s
index 37dddf57..30a0146b 100644
--- a/src/thread/mips/clone.s
+++ b/src/thread/mips/clone.s
@@ -28,5 +28,8 @@ __clone:
 	nop
 1:	lw $25, 0($sp)
 	lw $4, 4($sp)
-	jr $25
+	jalr $25
 	nop
+	move $4, $2
+	li $2, 4001
+	syscall
-- 
2.18.0

[PATCH 2/3] mips64: Call exit on return from fn in __clone

[Segev Finer]

This is the expected behavior of this function.  Without this the child
task will crash on return from fn, since it will return to
nowhere.
---
 src/thread/mips64/clone.s | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/thread/mips64/clone.s b/src/thread/mips64/clone.s
index 229d2677..1b71e07c 100644
--- a/src/thread/mips64/clone.s
+++ b/src/thread/mips64/clone.s
@@ -26,5 +26,8 @@ __clone:
 	nop
 1:	ld	$25, 0($sp)	# function pointer
 	ld	$4, 8($sp)	# argument pointer
-	jr	$25		# call the user's function
+	jalr	$25		# call the user's function
 	nop
+	move 	$4, $2
+	li	$2, 5058
+	syscall
-- 
2.18.0

[PATCH 3/3] mipsn32: Call exit on return from fn in __clone

[Segev Finer]

This is the expected behavior of this function.  Without this the child
task will crash on return from fn, since it will return to
nowhere.
---
 src/thread/mipsn32/clone.s | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/thread/mipsn32/clone.s b/src/thread/mipsn32/clone.s
index 51035852..ebf5dbea 100644
--- a/src/thread/mipsn32/clone.s
+++ b/src/thread/mipsn32/clone.s
@@ -26,5 +26,8 @@ __clone:
 	nop
 1:	lw	$25, 0($sp)	# function pointer
 	lw	$4, 4($sp)	# argument pointer
-	jr	$25		# call the user's function
+	jalr	$25		# call the user's function
 	nop
+	move 	$4, $2
+	li	$2, 6058
+	syscall
-- 
2.18.0

Re: [PATCH 0/3] mips{,64,n32}: Call exit on return from fn in __clone

[Szabolcs Nagy]

* Segev Finer <segev208@gmail.com> [2018-08-15 20:46:17 +0300]:
> This is the expected behavior of this function.  Without this the child
> task will crash on return from fn, since it will return to nowhere.
> 
> I only tested MIPS O32.
> 

sounds right to me, it affects users who call raw clone,
the child function used in pthread_create in musl does
not return so conforming posix code is not affected.

> Segev Finer (3):
>   mips: Call exit on return from fn in __clone
>   mips64: Call exit on return from fn in __clone
>   mipsn32: Call exit on return from fn in __clone
> 
>  src/thread/mips/clone.s    | 5 ++++-
>  src/thread/mips64/clone.s  | 5 ++++-
>  src/thread/mipsn32/clone.s | 5 ++++-
>  3 files changed, 12 insertions(+), 3 deletions(-)
> 
> --
> 2.18.0

Re: [PATCH 0/3] mips{,64,n32}: Call exit on return from fn in __clone

[Rich Felker]

On Wed, Aug 15, 2018 at 08:46:17PM +0300, Segev Finer wrote:
> This is the expected behavior of this function.  Without this the child
> task will crash on return from fn, since it will return to nowhere.
> 
> I only tested MIPS O32.
> 
> Segev Finer (3):
>   mips: Call exit on return from fn in __clone
>   mips64: Call exit on return from fn in __clone
>   mipsn32: Call exit on return from fn in __clone
> 
>  src/thread/mips/clone.s    | 5 ++++-
>  src/thread/mips64/clone.s  | 5 ++++-
>  src/thread/mipsn32/clone.s | 5 ++++-
>  3 files changed, 12 insertions(+), 3 deletions(-)
> 
> --
> 2.18.0

These look fine, but I'm merging them into one commit. Thanks. Also
noting that the public interface fixed is clone() (vs __clone which is
internal).

Rich