diff options
Diffstat (limited to 'arch/x86/kernel/signal_32.c')
| -rw-r--r-- | arch/x86/kernel/signal_32.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c index 2553136cf39b..f042dcdf1f16 100644 --- a/arch/x86/kernel/signal_32.c +++ b/arch/x86/kernel/signal_32.c @@ -54,12 +54,14 @@ static inline void reload_segments(struct sigcontext_32 *sc) } #define sigset32_t compat_sigset_t +#define siginfo32_t compat_siginfo_t #define restore_altstack32 compat_restore_altstack #define unsafe_save_altstack32 unsafe_compat_save_altstack #else #define sigset32_t sigset_t +#define siginfo32_t siginfo_t #define __NR_ia32_sigreturn __NR_sigreturn #define __NR_ia32_rt_sigreturn __NR_rt_sigreturn #define restore_altstack32 restore_altstack @@ -377,3 +379,128 @@ Efault: user_access_end(); return -EFAULT; } + +/* + * The siginfo_t structure and handing code is very easy + * to break in several ways. It must always be updated when new + * updates are made to the main siginfo_t, and + * copy_siginfo_to_user32() must be updated when the + * (arch-independent) copy_siginfo_to_user() is updated. + * + * It is also easy to put a new member in the siginfo_t + * which has implicit alignment which can move internal structure + * alignment around breaking the ABI. This can happen if you, + * for instance, put a plain 64-bit value in there. + */ + +/* +* If adding a new si_code, there is probably new data in +* the siginfo. Make sure folks bumping the si_code +* limits also have to look at this code. Make sure any +* new fields are handled in copy_siginfo_to_user32()! +*/ +static_assert(NSIGILL == 11); +static_assert(NSIGFPE == 15); +static_assert(NSIGSEGV == 9); +static_assert(NSIGBUS == 5); +static_assert(NSIGTRAP == 6); +static_assert(NSIGCHLD == 6); +static_assert(NSIGSYS == 2); + +/* This is part of the ABI and can never change in size: */ +static_assert(sizeof(siginfo32_t) == 128); + +/* This is a part of the ABI and can never change in alignment */ +static_assert(__alignof__(siginfo32_t) == 4); + +/* +* The offsets of all the (unioned) si_fields are fixed +* in the ABI, of course. Make sure none of them ever +* move and are always at the beginning: +*/ +static_assert(offsetof(siginfo32_t, _sifields) == 3 * sizeof(int)); + +static_assert(offsetof(siginfo32_t, si_signo) == 0); +static_assert(offsetof(siginfo32_t, si_errno) == 4); +static_assert(offsetof(siginfo32_t, si_code) == 8); + +/* +* Ensure that the size of each si_field never changes. +* If it does, it is a sign that the +* copy_siginfo_to_user32() code below needs to updated +* along with the size in the CHECK_SI_SIZE(). +* +* We repeat this check for both the generic and compat +* siginfos. +* +* Note: it is OK for these to grow as long as the whole +* structure stays within the padding size (checked +* above). +*/ + +#define CHECK_SI_OFFSET(name) \ + static_assert(offsetof(siginfo32_t, _sifields) == \ + offsetof(siginfo32_t, _sifields.name)) + +#define CHECK_SI_SIZE(name, size) \ + static_assert(sizeof_field(siginfo32_t, _sifields.name) == size) + +CHECK_SI_OFFSET(_kill); +CHECK_SI_SIZE (_kill, 2*sizeof(int)); +static_assert(offsetof(siginfo32_t, si_pid) == 0xC); +static_assert(offsetof(siginfo32_t, si_uid) == 0x10); + +CHECK_SI_OFFSET(_timer); +#ifdef CONFIG_COMPAT +/* compat_siginfo_t doesn't have si_sys_private */ +CHECK_SI_SIZE (_timer, 3*sizeof(int)); +#else +CHECK_SI_SIZE (_timer, 4*sizeof(int)); +#endif +static_assert(offsetof(siginfo32_t, si_tid) == 0x0C); +static_assert(offsetof(siginfo32_t, si_overrun) == 0x10); +static_assert(offsetof(siginfo32_t, si_value) == 0x14); + +CHECK_SI_OFFSET(_rt); +CHECK_SI_SIZE (_rt, 3*sizeof(int)); +static_assert(offsetof(siginfo32_t, si_pid) == 0x0C); +static_assert(offsetof(siginfo32_t, si_uid) == 0x10); +static_assert(offsetof(siginfo32_t, si_value) == 0x14); + +CHECK_SI_OFFSET(_sigchld); +CHECK_SI_SIZE (_sigchld, 5*sizeof(int)); +static_assert(offsetof(siginfo32_t, si_pid) == 0x0C); +static_assert(offsetof(siginfo32_t, si_uid) == 0x10); +static_assert(offsetof(siginfo32_t, si_status) == 0x14); +static_assert(offsetof(siginfo32_t, si_utime) == 0x18); +static_assert(offsetof(siginfo32_t, si_stime) == 0x1C); + +CHECK_SI_OFFSET(_sigfault); +CHECK_SI_SIZE (_sigfault, 4*sizeof(int)); +static_assert(offsetof(siginfo32_t, si_addr) == 0x0C); + +static_assert(offsetof(siginfo32_t, si_trapno) == 0x10); + +static_assert(offsetof(siginfo32_t, si_addr_lsb) == 0x10); + +static_assert(offsetof(siginfo32_t, si_lower) == 0x14); +static_assert(offsetof(siginfo32_t, si_upper) == 0x18); + +static_assert(offsetof(siginfo32_t, si_pkey) == 0x14); + +static_assert(offsetof(siginfo32_t, si_perf_data) == 0x10); +static_assert(offsetof(siginfo32_t, si_perf_type) == 0x14); +static_assert(offsetof(siginfo32_t, si_perf_flags) == 0x18); + +CHECK_SI_OFFSET(_sigpoll); +CHECK_SI_SIZE (_sigpoll, 2*sizeof(int)); +static_assert(offsetof(siginfo32_t, si_band) == 0x0C); +static_assert(offsetof(siginfo32_t, si_fd) == 0x10); + +CHECK_SI_OFFSET(_sigsys); +CHECK_SI_SIZE (_sigsys, 3*sizeof(int)); +static_assert(offsetof(siginfo32_t, si_call_addr) == 0x0C); +static_assert(offsetof(siginfo32_t, si_syscall) == 0x10); +static_assert(offsetof(siginfo32_t, si_arch) == 0x14); + +/* any new si_fields should be added here */ |