• Michael Ellerman's avatar
    powerpc: Fix random memory corruption in merged elf.h · 30415f6a
    Michael Ellerman authored
    The merged verison of ELF_CORE_COPY_REGS is basically the PPC64 version, with
    a memset that came from PPC and a few types abstracted out into #defines. But
    it's not _quite_ right.
    
    The first problem is we calculate the number of registers with:
            nregs = sizeof(struct pt_regs) / sizeof(ELF_GREG_TYPE)
    
    For a 32-bit process on a 64-bit kernel that's bogus because the registers are
    64 bits, but ELF_GREG_TYPE is u32, so nregs == 88 which is wrong.
    
    The other problem is the memset, which assumes a struct pt_regs is smaller
    than a struct elf_regs. For a 32-bit process on a 64-bit kernel that's false.
    
    The fix is to calculate the number of regs using sizeof(unsigned long), which
    should always be right, and just memset the whole damn thing _before_ copying
    the registers in.
    Signed-off-by: default avatarMichael Ellerman <michael@ellerman.id.au>
    30415f6a
elf.h 17 KB