ILP32 support uses the same struct sigcontext as the native ABI (i.e., LP64), but a different layout for the rest of the signal frame (since siginfo_t and ucontext_t are both ABI-dependent). Since the purpose of parse_user_sigframe() is really to parse sigcontext and not the whole signal frame, the function does not need to depend on the layout of rt_sigframe -- the only purpose of the rt_sigframe pointer is for use as a base to measure the signal frame size. So, this patch renames the function to parse_user_sigcontext() and makes the sigframe base pointer generic. ABI-specific parsers that share the same sigcontext definition can then call it. To minimise churn in this patch, the native LP64 parser is retained under the old name, but becomes a call to parse_user_sigconext(). It may make sense instead to fold this into its restore_sigframe(), depending on how ILP32 support is integrated. Suggested-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx> --- This patch depends on [1], which does not appear to be applied yet. [1] [PATCH] arm64: signal: Allow expansion of the signal frame http://lists.infradead.org/pipermail/linux-arm-kernel/2017-June/514699.html arch/arm64/kernel/signal.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index e47cd3a..a189321 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -223,16 +223,16 @@ struct user_ctxs { struct fpsimd_context __user *fpsimd; }; -static int parse_user_sigframe(struct user_ctxs *user, - struct rt_sigframe __user *sf) +static int parse_user_sigcontext(struct user_ctxs *user, + struct sigcontext __user const *sc, + void __user const *sigframe_base) { - struct sigcontext __user *const sc = &sf->uc.uc_mcontext; struct _aarch64_ctx __user *head; char __user *base = (char __user *)&sc->__reserved; size_t offset = 0; size_t limit = sizeof(sc->__reserved); bool have_extra_context = false; - char const __user *const sfp = (char const __user *)sf; + char const __user *const sfp = (char const __user *)sigframe_base; user->fpsimd = NULL; @@ -366,6 +366,12 @@ static int parse_user_sigframe(struct user_ctxs *user, return -EINVAL; } +static int parse_user_sigframe(struct user_ctxs *user, + struct rt_sigframe __user const *sf) +{ + return parse_user_sigcontext(user, &sf->uc.uc_mcontext, sf); +} + static int restore_sigframe(struct pt_regs *regs, struct rt_sigframe __user *sf) { -- 2.1.4
