From: ebiederm@xmission.com (Eric W. Biederman)
To: Marco Elver <elver@google.com>
Cc: linux@armlinux.org.uk, catalin.marinas@arm.com, will@kernel.org,
davem@davemloft.net, mark.rutland@arm.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org
Subject: Re: [PATCH 1/3] sparc64: Add compile-time asserts for siginfo_t offsets
Date: Fri, 30 Apr 2021 12:42:15 -0500 [thread overview]
Message-ID: <m1im43zn2g.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <20210429190734.624918-1-elver@google.com> (Marco Elver's message of "Thu, 29 Apr 2021 21:07:32 +0200")
Marco Elver <elver@google.com> writes:
> 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.
Arnd Bergman recently pointed out that we can move si_trapno into the
union and make it specific to a handful of signals. Like we do other
items in the union.
Given that the code of perf_sigtrap is pretty much broken if si_trapno
needs to be filled out. I think we should make that change before
we set this ABI in stone like this.
Otherwise this looks good.
Eric
> Link: https://lkml.kernel.org/r/m11rat9f85.fsf@fess.ebiederm.org
> Suggested-by: Eric W. Biederman <ebiederm@xmission.com>
> Signed-off-by: Marco Elver <elver@google.com>
> ---
> arch/sparc/kernel/signal32.c | 34 ++++++++++++++++++++++++++++++++++
> arch/sparc/kernel/signal_64.c | 33 +++++++++++++++++++++++++++++++++
> 2 files changed, 67 insertions(+)
>
> diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c
> index e9695a06492f..778ed5c26d4a 100644
> --- a/arch/sparc/kernel/signal32.c
> +++ b/arch/sparc/kernel/signal32.c
> @@ -745,3 +745,37 @@ 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) == 0x14);
> +static_assert(offsetof(compat_siginfo_t, si_lower) == 0x18);
> +static_assert(offsetof(compat_siginfo_t, si_upper) == 0x1c);
> +static_assert(offsetof(compat_siginfo_t, si_pkey) == 0x18);
> +static_assert(offsetof(compat_siginfo_t, si_perf) == 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..c9bbf5f29078 100644
> --- a/arch/sparc/kernel/signal_64.c
> +++ b/arch/sparc/kernel/signal_64.c
> @@ -556,3 +556,36 @@ 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) == 0x20);
> +static_assert(offsetof(siginfo_t, si_lower) == 0x28);
> +static_assert(offsetof(siginfo_t, si_upper) == 0x30);
> +static_assert(offsetof(siginfo_t, si_pkey) == 0x28);
> +static_assert(offsetof(siginfo_t, si_perf) == 0x20);
> +static_assert(offsetof(siginfo_t, si_band) == 0x10);
> +static_assert(offsetof(siginfo_t, si_fd) == 0x14);
next prev parent reply other threads:[~2021-04-30 17:42 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-29 19:07 [PATCH 1/3] sparc64: Add compile-time asserts for siginfo_t offsets Marco Elver
2021-04-29 19:07 ` [PATCH 2/3] arm: " Marco Elver
2021-04-29 19:07 ` [PATCH 3/3] arm64: " Marco Elver
2021-05-26 17:42 ` Will Deacon
2021-05-26 17:50 ` Marco Elver
2021-05-26 18:29 ` Will Deacon
2021-07-02 8:51 ` Marco Elver
2021-07-12 10:38 ` Marco Elver
2021-04-30 17:42 ` Eric W. Biederman [this message]
2021-04-30 18:11 ` [PATCH 1/3] sparc64: " Marco Elver
2021-04-30 22:22 ` David Miller
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