diff options
Diffstat (limited to 'devel/st/files/patch-md.h')
| -rw-r--r-- | devel/st/files/patch-md.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/devel/st/files/patch-md.h b/devel/st/files/patch-md.h new file mode 100644 index 000000000000..c423b4501f63 --- /dev/null +++ b/devel/st/files/patch-md.h @@ -0,0 +1,22 @@ +--- md.h 2009-10-01 20:46:43.000000000 +0200 ++++ md.h 2014-12-16 22:52:34.000000000 +0100 +@@ -161,6 +161,19 @@ + #define MD_JB_SP 34 + #elif defined(__amd64__) + #define MD_JB_SP 2 ++/* ++ * The following comment is taken from src/lib/libc/amd64/gen/makecontext.c ++ * It explains why we specifically break the alignment to 64 byte boundary ++ * that is unconditionally enforced by sched.c, by setting MD_STACK_PAD_SIZE ++ * to this funky value. ++ * Without this, anything using va_start() & friends fails unpredictably. ++ */ ++ /* ++ * Account for arguments on stack and do the funky C entry alignment. ++ * This means that we need an 8-byte-odd alignment since the ABI expects ++ * the return address to be pushed, thus breaking the 16 byte alignment. ++ */ ++#define MD_STACK_PAD_SIZE 8 + #else + #error Unknown CPU architecture + #endif |