On 08/05/13 at 01:35pm, Vivek Goyal wrote: > I think struct x86_linux_param_header should be packed. Strange that we > did not do it so far. > > Without packing struct size was 3824 (decimal) on my x86_64 machine. With > packing it is 3820. I think there was a padding of 4 bytes at the end. So > it should be harmless. > > I tried to introduce more fields and that introduced padding in the > middle of structure and kexec stopped working and that's how I got to > know that bootparam is not packed. In this case that's true and x86_linux_param_header should be packed. One more thing is, in include/x86/x86-linux.h, we already define PACKED macro: #define PACKED __attribute__((packed)) But within x86-linux.h, both PACKED_and __attribute__((packed)) are used. PACKED isn't used much time and __attribute__((packed)) is quite simple and straightforward. Maybe it's time we can remove the macro and use __attribute__((packed)) directly. I can send another patch to address this if anyone thinks it's a good idea. Thanks WANG Chao > --- > include/x86/x86-linux.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: kexec-tools/include/x86/x86-linux.h > =================================================================== > --- kexec-tools.orig/include/x86/x86-linux.h 2013-08-05 13:28:33.999338740 -0400 > +++ kexec-tools/include/x86/x86-linux.h 2013-08-05 13:28:46.616475104 -0400 > @@ -198,7 +198,7 @@ struct x86_linux_param_header { > struct edd_info eddbuf[EDDMAXNR]; /* 0xd00 */ > /* 0xeec */ > #define COMMAND_LINE_SIZE 2048 > -}; > +} __attribute__ ((packed)); > > struct x86_linux_faked_param_header { > struct x86_linux_param_header hdr; /* 0x00 */ > > _______________________________________________ > kexec mailing list > kexec at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec