Cast the argument of the g2h() macro to a target_ulong so that it isn't accidentally sign-extended if it is a signed 32 bit type and long is a 64 bit type. In particular, this fixes a bug where it would return the wrong value for 32 bit guests on 64 bit hosts when passed in one of the arg* values from do_syscall() [which are all abi_long and thus signed types]. This could result in spurious failure of mlock(), among others.
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> --- This should be committed before Alex's patch to make mmap allocate downwards (http://patchwork.ozlabs.org/patch/144476/) because that hugely increases the chances that g2h will get passed a pointer that has the high bit set. cpu-all.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/cpu-all.h b/cpu-all.h index 80e6d42..a174532 100644 --- a/cpu-all.h +++ b/cpu-all.h @@ -197,7 +197,7 @@ extern unsigned long reserved_va; #endif /* All direct uses of g2h and h2g need to go away for usermode softmmu. */ -#define g2h(x) ((void *)((unsigned long)(x) + GUEST_BASE)) +#define g2h(x) ((void *)((unsigned long)(target_ulong)(x) + GUEST_BASE)) #if HOST_LONG_BITS <= TARGET_VIRT_ADDR_SPACE_BITS #define h2g_valid(x) 1 -- 1.7.1
