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coroutine-sigaltstack: Change jmp_buf to sigjmp_buf

PATCH Applied Willem Pinckaers 4 participants 4 messages Nov 8, 2014 – Nov 11, 2014

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Willem Pinckaers

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#0 lore raw

PATCH 1/1 coroutine-sigaltstack: Change jmp_buf to sigjmp_buf

This is a simple patch to change the type of old_env from jmp_buf to sigjmp_buf. old_env is used by sigsetjmp and as such should be a sigjmp_buf.

This fixes a stack_chk fail in a OSX 32bit build. Since at least on OSX sigjmp_buf is four bytes larger then a jmpbuf, resulting in an overflow in sigsetjmp. Due to variable reordering this overwrites the stack cookie.

Signed-off-by Willem Pinckaers <[email protected]>
---
 coroutine-sigaltstack.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
coroutine-sigaltstack.c +1 -1
index 3de0bb3..63519ff 100644
@@ -155,7 +155,7 @@ Coroutine *qemu_coroutine_new(void)
     stack_t oss;
     sigset_t sigs;
     sigset_t osigs;
-    jmp_buf old_env;
+    sigjmp_buf old_env;
 
     /* The way to manipulate stack is with the sigaltstack function. We
      * prepare a stack, with it delivering a signal to ourselves and then
Signature · 1 line
1.9.3 (Apple Git-50)
Reviewed-by on v1 1/1
#1 lore raw
Quoted 19 lines · Willem Pinckaers

This is a simple patch to change the type of old_env from jmp_buf to sigjmp_buf. old_env is used by sigsetjmp and as such should be a sigjmp_buf.

This fixes a stack_chk fail in a OSX 32bit build. Since at least on OSX sigjmp_buf is four bytes larger then a jmpbuf, resulting in an overflow in sigsetjmp. Due to variable reordering this overwrites the stack cookie.

Signed-off-by Willem Pinckaers <[email protected]>
---
 coroutine-sigaltstack.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
coroutine-sigaltstack.c +0 -0
index 3de0bb3..63519ff 100644

coroutine-sigaltstack.c Coroutine *qemu_coroutine_new(void) · line 161

Quoted 8 lines
coroutine-sigaltstack.c +1 -1
@@ -155,7 +155,7 @@ Coroutine *qemu_coroutine_new(void)
     stack_t oss;
     sigset_t sigs;
     sigset_t osigs;
-    jmp_buf old_env;
+    sigjmp_buf old_env;
 
     /* The way to manipulate stack is with the sigaltstack function. We
      * prepare a stack, with it delivering a signal to ourselves and then
Reviewed-by Peter Maydell <[email protected]>

I think I must have missed this one when I converted all the jmp_buf to sigjmp_buf in commit 6ab7e546.

-- PMM

#2 lore raw
Quoted 26 lines · Peter Maydell
Quoted 25 lines · Willem Pinckaers

This is a simple patch to change the type of old_env from jmp_buf to sigjmp_buf. old_env is used by sigsetjmp and as such should be a sigjmp_buf.

This fixes a stack_chk fail in a OSX 32bit build. Since at least on OSX sigjmp_buf is four bytes larger then a jmpbuf, resulting in an overflow in sigsetjmp. Due to variable reordering this overwrites the stack cookie.

Signed-off-by Willem Pinckaers <[email protected]>
---
 coroutine-sigaltstack.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
coroutine-sigaltstack.c +1 -1
index 3de0bb3..63519ff 100644
@@ -155,7 +155,7 @@ Coroutine *qemu_coroutine_new(void)
     stack_t oss;
     sigset_t sigs;
     sigset_t osigs;
-    jmp_buf old_env;
+    sigjmp_buf old_env;
Quoted 7 lines

coroutine-sigaltstack.c Coroutine *qemu_coroutine_new(void) · line 161

Quoted 2 lines
coroutine-sigaltstack.c +0 -0
     /* The way to manipulate stack is with the sigaltstack function. We
      * prepare a stack, with it delivering a signal to ourselves and then
Reviewed-by Peter Maydell <[email protected]>

I think I must have missed this one when I converted all the jmp_buf to sigjmp_buf in commit 6ab7e546.

Useful bit of information, perhaps you can amend the commit message with it on commit.