From 4be33329d46f80e87afe7db61271d1370607260a Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 2 Apr 2018 15:10:57 -0500 Subject: m68k: Verify the offsets in struct siginfo never change. A change to the generic struct siginfo accidentally changed the offset of si_offset. Add build time checks to ensure the offsets of all known fields in struct siginfo never change. This copies the form of similar changes on x86. Signed-off-by: "Eric W. Biederman" --- arch/m68k/kernel/signal.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) (limited to 'arch/m68k/kernel') diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c index e79421f5b9cd..f7cd5ecfacd3 100644 --- a/arch/m68k/kernel/signal.c +++ b/arch/m68k/kernel/signal.c @@ -574,6 +574,66 @@ static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs * #endif /* CONFIG_FPU */ +static inline void siginfo_build_tests(void) +{ + /* This needs to be tested on m68k as it has a lesser + * alignment requirment than x86 and that can cause surprises. + */ + + /* This is part of the ABI and can never change in size: */ + BUILD_BUG_ON(sizeof(siginfo_t) != 128); + + /* Ensure the know fields never change in location */ + BUILD_BUG_ON(offsetof(siginfo_t, si_signo) != 0); + BUILD_BUG_ON(offsetof(siginfo_t, si_errno) != 4); + BUILD_BUG_ON(offsetof(siginfo_t, si_code) != 8); + + /* _kill */ + BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0C); + BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10); + + /* _timer */ + BUILD_BUG_ON(offsetof(siginfo_t, si_tid) != 0x0C); + BUILD_BUG_ON(offsetof(siginfo_t, si_overrun) != 0x10); + BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x14); + + /* _rt */ + BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0C); + BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10); + BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x14); + + /* _sigchld */ + BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x0C); + BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x10); + BUILD_BUG_ON(offsetof(siginfo_t, si_status) != 0x14); + BUILD_BUG_ON(offsetof(siginfo_t, si_utime) != 0x18); + BUILD_BUG_ON(offsetof(siginfo_t, si_stime) != 0x1C); + + /* _sigfault */ + BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x0C); + + /* _sigfault._mcerr */ + BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x10); + + /* _sigfault._addr_bnd */ + BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x12); + BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x16); + + /* _sigfault._addr_pkey */ + BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x12); + + /* _sigpoll */ + BUILD_BUG_ON(offsetof(siginfo_t, si_band) != 0x0C); + BUILD_BUG_ON(offsetof(siginfo_t, si_fd) != 0x10); + + /* _sigsys */ + BUILD_BUG_ON(offsetof(siginfo_t, si_call_addr) != 0x0C); + BUILD_BUG_ON(offsetof(siginfo_t, si_syscall) != 0x10); + BUILD_BUG_ON(offsetof(siginfo_t, si_arch) != 0x14); + + /* any new si_fields should be added here */ +} + static int mangle_kernel_stack(struct pt_regs *regs, int formatvec, void __user *fp) { @@ -635,6 +695,8 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __u struct sigcontext context; int err = 0; + siginfo_build_tests(); + /* Always make any pending restarted system calls return -EINTR */ current->restart_block.fn = do_no_restart_syscall; -- cgit v1.2.3