On Sun, Jun 17, 2018 at 12:22 PM, Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk> wrote: > On 15/06/18 11:37, Thomas Huth wrote: > >> Hi Mark, hi Artyom, >> >> while using valgrind to fix some issues with the rom_ptr() function >> today, I noticed that there is one more problem in sun4u_load_kernel(): >> The kernel_top variable can be used uninitialized in some cases: >> If load_elf() fails and the kernel is loaded via load_aout() or >> load_image_targphys(), the kernel_top variable is never set to a valid >> value. This could cause some trouble when loading the initrd later. When >> you've got some spare time, could you please have a look? > > > Hmmm that's an interesting one - I'm not immediately aware of any 64-bit > kernels that are a.out rather than ELF, so I wonder if this has been used to > run a.out executables on startup? Any thoughts, Artyom?
I think there are no Linux/SPARC64 kernels in the a.out format. NetBSD should not be a problem either > If this is the case then we can only have a valid kernel_top with an ELF > kernel then maybe the following is a good enough solution: > > > diff --git a/hw/sparc64/sun4u.c b/hw/sparc64/sun4u.c > index 3975a7b65a..35acf8c96e 100644 > --- a/hw/sparc64/sun4u.c > +++ b/hw/sparc64/sun4u.c > @@ -139,7 +139,7 @@ static uint64_t sun4u_load_kernel(const char > *kernel_filename, > unsigned int i; > long kernel_size; > uint8_t *ptr; > - uint64_t kernel_top; > + uint64_t kernel_top = 0; > > linux_boot = (kernel_filename != NULL); > > @@ -172,7 +172,7 @@ static uint64_t sun4u_load_kernel(const char > *kernel_filename, > } > /* load initrd above kernel */ > *initrd_size = 0; > - if (initrd_filename) { > + if (initrd_filename && kernel_top) { > *initrd_addr = TARGET_PAGE_ALIGN(kernel_top); > > *initrd_size = load_image_targphys(initrd_filename, > > Looks good to me. Acked-by: Artyom Tarasenko <atar4q...@gmail.com> -- Regards, Artyom Tarasenko SPARC and PPC PReP under qemu blog: http://tyom.blogspot.com/search/label/qemu