signal/x86: Include the field offsets in the build time checks
Due to an oversight when refactoring siginfo_t si_pkey has been in the
wrong position since 4.16-rc1. Add an explicit check of the offset of
every user space field in siginfo_t and compat_siginfo_t to make a
mistake like this hard to make in the future.
I have run this code on 4.15 and 4.16-rc1 with the position of si_pkey
fixed and all of the fields show up in the same location.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index ac057f9..0d930d8 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c
@@ -43,6 +43,13 @@ static inline void signal_compat_build_tests(void)
BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields) != 3 * sizeof(int));
#define CHECK_CSI_OFFSET(name) BUILD_BUG_ON(_sifields_offset != offsetof(compat_siginfo_t, _sifields.name))
+ 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);
+
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_signo) != 0);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_errno) != 4);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_code) != 8);
/*
* Ensure that the size of each si_field never changes.
* If it does, it is a sign that the
@@ -63,36 +70,94 @@ static inline void signal_compat_build_tests(void)
CHECK_CSI_SIZE (_kill, 2*sizeof(int));
CHECK_SI_SIZE (_kill, 2*sizeof(int));
+ BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0xC);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);
+
CHECK_CSI_OFFSET(_timer);
CHECK_CSI_SIZE (_timer, 3*sizeof(int));
CHECK_SI_SIZE (_timer, 6*sizeof(int));
+ BUILD_BUG_ON(offsetof(siginfo_t, si_tid) != 0x10);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_overrun) != 0x14);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x18);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_tid) != 0x0C);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_overrun) != 0x10);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_value) != 0x14);
+
CHECK_CSI_OFFSET(_rt);
CHECK_CSI_SIZE (_rt, 3*sizeof(int));
CHECK_SI_SIZE (_rt, 4*sizeof(int));
+ BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x18);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0x0C);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_value) != 0x14);
+
CHECK_CSI_OFFSET(_sigchld);
CHECK_CSI_SIZE (_sigchld, 5*sizeof(int));
CHECK_SI_SIZE (_sigchld, 8*sizeof(int));
+ BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_status) != 0x18);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_utime) != 0x20);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_stime) != 0x28);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0x0C);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_status) != 0x14);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_utime) != 0x18);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_stime) != 0x1C);
+
#ifdef CONFIG_X86_X32_ABI
CHECK_CSI_OFFSET(_sigchld_x32);
CHECK_CSI_SIZE (_sigchld_x32, 7*sizeof(int));
/* no _sigchld_x32 in the generic siginfo_t */
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields._sigchld_x32._utime) != 0x18);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields._sigchld_x32._stime) != 0x20);
#endif
CHECK_CSI_OFFSET(_sigfault);
CHECK_CSI_SIZE (_sigfault, 4*sizeof(int));
CHECK_SI_SIZE (_sigfault, 8*sizeof(int));
+ BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x10);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr) != 0x0C);
+
+ BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x18);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr_lsb) != 0x10);
+
+ BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x20);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x28);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_lower) != 0x14);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_upper) != 0x18);
+
+ BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x20);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pkey) != 0x14);
+
CHECK_CSI_OFFSET(_sigpoll);
CHECK_CSI_SIZE (_sigpoll, 2*sizeof(int));
CHECK_SI_SIZE (_sigpoll, 4*sizeof(int));
+ BUILD_BUG_ON(offsetof(siginfo_t, si_band) != 0x10);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_fd) != 0x18);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_band) != 0x0C);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_fd) != 0x10);
+
CHECK_CSI_OFFSET(_sigsys);
CHECK_CSI_SIZE (_sigsys, 3*sizeof(int));
CHECK_SI_SIZE (_sigsys, 4*sizeof(int));
+ BUILD_BUG_ON(offsetof(siginfo_t, si_call_addr) != 0x10);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_syscall) != 0x18);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_arch) != 0x1C);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_call_addr) != 0x0C);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_syscall) != 0x10);
+ BUILD_BUG_ON(offsetof(compat_siginfo_t, si_arch) != 0x14);
+
/* any new si_fields should be added here */
}