[PATCH] mkimage: fix segfault on MacOS arm64

[Sergey V. Lobanov]

Thanks a lot for your review, I’ve sent PATCH v2 with the changes related to your comments

https://lists.denx.de/pipermail/u-boot/2022-January/472133.html


> On 11 Jan 2022, at 22:42, Jessica Clarke <jrtc27 at jrtc27.com> wrote:
> 
> On 2 Dec 2021, at 22:16, Sergey V. Lobanov <sergey at lobanov.in> wrote:
>> 
>> mkimage segfaults due ASLR mechasim on MacOS arm64
>> 
>> It is required to use _dyld_get_image_vmaddr_slide()
>> to prevent segfault on MacOS arm64
>> 
>> This patch ased on the discussion
>> https://github.com/u-boot/u-boot/commit/3b142045e8a7f0ab17b6099e9226296af45967d0
>> 
>> Thanks to Ronny Kotzschmar and ptpt52 github user
>> 
>> Signed-off-by: Sergey V. Lobanov <sergey at lobanov.in>
>> ---
>> tools/imagetool.h | 8 ++++++--
>> 1 file changed, 6 insertions(+), 2 deletions(-)
>> 
>> diff --git a/tools/imagetool.h b/tools/imagetool.h
>> index e229a34ffc..13775ff9b3 100644
>> --- a/tools/imagetool.h
>> +++ b/tools/imagetool.h
>> @@ -271,11 +271,16 @@ int rockchip_copy_image(int fd, struct image_tool_params *mparams);
>> *  b) we need a API call to get the respective section symbols */
>> #if defined(__MACH__)
>> #include <mach-o/getsect.h>
>> +#include <mach-o/dyld.h>
>> 
>> -#define INIT_SECTION(name)  do {					\
>> +#define INIT_SECTION(name)	struct image_type_params		\
>> +	**__cat(__start_, name), **__cat(__stop_, name);		\
> 
> This change alters the interface of INIT_SECTION. Previously it was
> just required that something had called it before you referenced the
> start/stop symbols. Now there are two things going on:
> 
> 1. Any references have to be in a scope that can see the INIT_SECTION
>   call.
> 2. This is no longer a single statement, so
>       if (foo)
>           INIT_SECTION(name);
>    breaks.
> 
> I don’t see why this change is needed, either. It should still be
> idempotent to set the global multiple times even after your change to
> add the base address, since that is done to the temporary local
> variable.
> 
>> +	do {								\
>> 		unsigned long name ## _len;				\
>> 		char *__cat(pstart_, name) = getsectdata("__DATA",	\
>> 			#name, &__cat(name, _len));			\
>> +			__cat(pstart_, name) +=				\
>> +				_dyld_get_image_vmaddr_slide(0);	\
> 
> Your formatting here is broken, you have an extra tab on both lines.
> 
> Jess
> 
>> 		char *__cat(pstop_, name) = __cat(pstart_, name) +	\
>> 			__cat(name, _len);				\
>> 		__cat(__start_, name) = (void *)__cat(pstart_, name);	\
>> @@ -283,7 +288,6 @@ int rockchip_copy_image(int fd, struct image_tool_params *mparams);
>> 	} while (0)
>> #define SECTION(name)   __attribute__((section("__DATA, " #name)))
>> 
>> -struct image_type_params **__start_image_type, **__stop_image_type;
>> #else
>> #define INIT_SECTION(name) /* no-op for ELF */
>> #define SECTION(name)   __attribute__((section(#name)))
>> -- 
>> 2.30.1 (Apple Git-130)