From: Marco Elver <elver@google.com>

Date: Thu, 29 Apr 2021 21:07:32 +0200

Subject: sparc64: Add compile-time asserts for siginfo_t offsets

Git-commit: 42365abdde2a22992e320ea5ae8f023d07352db3

Patch-mainline: v5.15-rc1

References: jsc#PED-1755 (dependent patch)

To help catch ABI breaks at compile-time, add compile-time assertions to

verify the siginfo_t layout. Unlike other architectures, sparc64 is

special, because it is one of few architectures requiring si_trapno.

ABI breaks around that field would only be caught here.

Link: https://lkml.kernel.org/r/m11rat9f85.fsf@fess.ebiederm.org

Link: https://lkml.kernel.org/r/20210429190734.624918-1-elver@google.com

Link: https://lkml.kernel.org/r/20210505141101.11519-1-ebiederm@xmission.com

Link: https://lkml.kernel.org/r/874kcvzbuu.fsf_-_@disp2133

Suggested-by: Eric W. Biederman <ebiederm@xmission.com>

Acked-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Marco Elver <elver@google.com>

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

Signed-off-by: Tony Jones <tonyj@suse.de>

---

 arch/sparc/kernel/signal32.c  | 35 +++++++++++++++++++++++++++++++++++

 arch/sparc/kernel/signal_64.c | 34 ++++++++++++++++++++++++++++++++++

 2 files changed, 69 insertions(+)

diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c

index e9695a06492f..65fd26ae9d25 100644

--- a/arch/sparc/kernel/signal32.c

+++ b/arch/sparc/kernel/signal32.c

@@ -745,3 +745,38 @@ asmlinkage int do_sys32_sigstack(u32 u_ssptr, u32 u_ossptr, unsigned long sp)

 out:

 	return ret;

 }

+

+/*

+ * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as

+ * changes likely come with new fields that should be added below.

+ */

+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);

+static_assert(offsetof(compat_siginfo_t, si_signo)	== 0x00);

+static_assert(offsetof(compat_siginfo_t, si_errno)	== 0x04);

+static_assert(offsetof(compat_siginfo_t, si_code)	== 0x08);

+static_assert(offsetof(compat_siginfo_t, si_pid)	== 0x0c);

+static_assert(offsetof(compat_siginfo_t, si_uid)	== 0x10);

+static_assert(offsetof(compat_siginfo_t, si_tid)	== 0x0c);

+static_assert(offsetof(compat_siginfo_t, si_overrun)	== 0x10);

+static_assert(offsetof(compat_siginfo_t, si_status)	== 0x14);

+static_assert(offsetof(compat_siginfo_t, si_utime)	== 0x18);

+static_assert(offsetof(compat_siginfo_t, si_stime)	== 0x1c);

+static_assert(offsetof(compat_siginfo_t, si_value)	== 0x14);

+static_assert(offsetof(compat_siginfo_t, si_int)	== 0x14);

+static_assert(offsetof(compat_siginfo_t, si_ptr)	== 0x14);

+static_assert(offsetof(compat_siginfo_t, si_addr)	== 0x0c);

+static_assert(offsetof(compat_siginfo_t, si_trapno)	== 0x10);

+static_assert(offsetof(compat_siginfo_t, si_addr_lsb)	== 0x10);

+static_assert(offsetof(compat_siginfo_t, si_lower)	== 0x14);

+static_assert(offsetof(compat_siginfo_t, si_upper)	== 0x18);

+static_assert(offsetof(compat_siginfo_t, si_pkey)	== 0x14);

+static_assert(offsetof(compat_siginfo_t, si_perf_data)	== 0x10);

+static_assert(offsetof(compat_siginfo_t, si_perf_type)	== 0x14);

+static_assert(offsetof(compat_siginfo_t, si_band)	== 0x0c);

+static_assert(offsetof(compat_siginfo_t, si_fd)		== 0x10);

diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c

index a0eec62c825d..a58e0cc45d24 100644

--- a/arch/sparc/kernel/signal_64.c

+++ b/arch/sparc/kernel/signal_64.c

@@ -556,3 +556,37 @@ void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long

 	user_enter();

 }

+/*

+ * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as

+ * changes likely come with new fields that should be added below.

+ */

+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);

+static_assert(offsetof(siginfo_t, si_signo)	== 0x00);

+static_assert(offsetof(siginfo_t, si_errno)	== 0x04);

+static_assert(offsetof(siginfo_t, si_code)	== 0x08);

+static_assert(offsetof(siginfo_t, si_pid)	== 0x10);

+static_assert(offsetof(siginfo_t, si_uid)	== 0x14);

+static_assert(offsetof(siginfo_t, si_tid)	== 0x10);

+static_assert(offsetof(siginfo_t, si_overrun)	== 0x14);

+static_assert(offsetof(siginfo_t, si_status)	== 0x18);

+static_assert(offsetof(siginfo_t, si_utime)	== 0x20);

+static_assert(offsetof(siginfo_t, si_stime)	== 0x28);

+static_assert(offsetof(siginfo_t, si_value)	== 0x18);

+static_assert(offsetof(siginfo_t, si_int)	== 0x18);

+static_assert(offsetof(siginfo_t, si_ptr)	== 0x18);

+static_assert(offsetof(siginfo_t, si_addr)	== 0x10);

+static_assert(offsetof(siginfo_t, si_trapno)	== 0x18);

+static_assert(offsetof(siginfo_t, si_addr_lsb)	== 0x18);

+static_assert(offsetof(siginfo_t, si_lower)	== 0x20);

+static_assert(offsetof(siginfo_t, si_upper)	== 0x28);

+static_assert(offsetof(siginfo_t, si_pkey)	== 0x20);

+static_assert(offsetof(siginfo_t, si_perf_data)	== 0x18);

+static_assert(offsetof(siginfo_t, si_perf_type)	== 0x20);

+static_assert(offsetof(siginfo_t, si_band)	== 0x10);

+static_assert(offsetof(siginfo_t, si_fd)	== 0x14);