Messages in this thread Patch in this message | | | From | Al Viro <> | Subject | [RFC][PATCH 13/22] x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers | Date | Mon, 23 Mar 2020 18:38:10 +0000 |
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From: Al Viro <viro@zeniv.linux.org.uk>
What's left is just a sequence of stores to userland addresses, with all error handling, etc. done out of line. Calling that from user_access block is safe, but rather than teaching objtool to recognize it as such we can just make it always_inline - it is small enough and has few enough callers, for the space savings not to be an issue.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- arch/x86/ia32/ia32_signal.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c index a96995aa23da..aedf9929f2b9 100644 --- a/arch/x86/ia32/ia32_signal.c +++ b/arch/x86/ia32/ia32_signal.c @@ -154,13 +154,10 @@ COMPAT_SYSCALL_DEFINE0(rt_sigreturn) #define get_user_seg(seg) ({ unsigned int v; savesegment(seg, v); v; }) -static int ia32_setup_sigcontext(struct sigcontext_32 __user *sc, +static __always_inline int ia32_setup_sigcontext(struct sigcontext_32 __user *sc, void __user *fpstate, struct pt_regs *regs, unsigned int mask) { - if (!user_access_begin(sc, sizeof(struct sigcontext_32))) - return -EFAULT; - unsafe_put_user(get_user_seg(gs), (unsigned int __user *)&sc->gs, Efault); unsafe_put_user(get_user_seg(fs), (unsigned int __user *)&sc->fs, Efault); unsafe_put_user(get_user_seg(ds), (unsigned int __user *)&sc->ds, Efault); @@ -187,10 +184,9 @@ static int ia32_setup_sigcontext(struct sigcontext_32 __user *sc, /* non-iBCS2 extensions.. */ unsafe_put_user(mask, &sc->oldmask, Efault); unsafe_put_user(current->thread.cr2, &sc->cr2, Efault); - user_access_end(); return 0; + Efault: - user_access_end(); return -EFAULT; } @@ -255,9 +251,13 @@ int ia32_setup_frame(int sig, struct ksignal *ksig, if (__put_user(sig, &frame->sig)) return -EFAULT; - if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) + if (!user_access_begin(&frame->sc, sizeof(struct sigcontext_32))) return -EFAULT; + if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) + goto Efault; + user_access_end(); + if (__put_user(set->sig[1], &frame->extramask[0])) return -EFAULT; @@ -301,6 +301,9 @@ int ia32_setup_frame(int sig, struct ksignal *ksig, regs->ss = __USER32_DS; return 0; +Efault: + user_access_end(); + return -EFAULT; } int ia32_setup_rt_frame(int sig, struct ksignal *ksig, @@ -356,8 +359,11 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig, user_access_end(); err |= __copy_siginfo_to_user32(&frame->info, &ksig->info, false); + if (!user_access_begin(&frame->uc.uc_mcontext, sizeof(struct sigcontext_32))) + return -EFAULT; err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate, regs, set->sig[0]); + user_access_end(); err |= __put_user(*(__u64 *)set, (__u64 __user *)&frame->uc.uc_sigmask); if (err) -- 2.11.0
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