From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC][PATCH v2 12/22] x86: get rid of put_user_try in {ia32,x32}_setup_rt_frame()
Date: Fri, 27 Mar 2020 02:31:55 +0000 [thread overview]
Message-ID: <20200327023205.881896-12-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200327023205.881896-1-viro@ZenIV.linux.org.uk>
From: Al Viro <viro@zeniv.linux.org.uk>
Straightforward, except for compat_save_altstack_ex() stuck in those.
Replace that thing with an analogue that would use unsafe_put_user()
instead of put_user_ex() (called unsafe_compat_save_altstack()) and
be done with that...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
arch/x86/ia32/ia32_signal.c | 50 +++++++++++++++++++++++----------------------
arch/x86/kernel/signal.c | 33 ++++++++++++++++--------------
include/linux/compat.h | 9 ++++----
3 files changed, 49 insertions(+), 43 deletions(-)
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index af673ec23a2d..a96995aa23da 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -326,35 +326,34 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
- if (!access_ok(frame, sizeof(*frame)))
+ if (!user_access_begin(frame, sizeof(*frame)))
return -EFAULT;
- put_user_try {
- put_user_ex(sig, &frame->sig);
- put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
- put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
+ unsafe_put_user(sig, &frame->sig, Efault);
+ unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault);
+ unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault);
- /* Create the ucontext. */
- if (static_cpu_has(X86_FEATURE_XSAVE))
- put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
- else
- put_user_ex(0, &frame->uc.uc_flags);
- put_user_ex(0, &frame->uc.uc_link);
- compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
+ /* Create the ucontext. */
+ if (static_cpu_has(X86_FEATURE_XSAVE))
+ unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
+ else
+ unsafe_put_user(0, &frame->uc.uc_flags, Efault);
+ unsafe_put_user(0, &frame->uc.uc_link, Efault);
+ unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
- if (ksig->ka.sa.sa_flags & SA_RESTORER)
- restorer = ksig->ka.sa.sa_restorer;
- else
- restorer = current->mm->context.vdso +
- vdso_image_32.sym___kernel_rt_sigreturn;
- put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
+ if (ksig->ka.sa.sa_flags & SA_RESTORER)
+ restorer = ksig->ka.sa.sa_restorer;
+ else
+ restorer = current->mm->context.vdso +
+ vdso_image_32.sym___kernel_rt_sigreturn;
+ unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
- /*
- * Not actually used anymore, but left because some gdb
- * versions need it.
- */
- put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
- } put_user_catch(err);
+ /*
+ * Not actually used anymore, but left because some gdb
+ * versions need it.
+ */
+ unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
+ user_access_end();
err |= __copy_siginfo_to_user32(&frame->info, &ksig->info, false);
err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
@@ -380,4 +379,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
regs->ss = __USER32_DS;
return 0;
+Efault:
+ user_access_end();
+ return -EFAULT;
}
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 3b4ca484cfc2..29abad29aaa1 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -529,6 +529,9 @@ static int x32_setup_rt_frame(struct ksignal *ksig,
int err = 0;
void __user *fpstate = NULL;
+ if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
+ return -EFAULT;
+
frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);
if (!access_ok(frame, sizeof(*frame)))
@@ -541,22 +544,17 @@ static int x32_setup_rt_frame(struct ksignal *ksig,
uc_flags = frame_uc_flags(regs);
- put_user_try {
- /* Create the ucontext. */
- put_user_ex(uc_flags, &frame->uc.uc_flags);
- put_user_ex(0, &frame->uc.uc_link);
- compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
- put_user_ex(0, &frame->uc.uc__pad0);
+ if (!user_access_begin(frame, sizeof(*frame)))
+ return -EFAULT;
- if (ksig->ka.sa.sa_flags & SA_RESTORER) {
- restorer = ksig->ka.sa.sa_restorer;
- } else {
- /* could use a vstub here */
- restorer = NULL;
- err |= -EFAULT;
- }
- put_user_ex(restorer, (unsigned long __user *)&frame->pretcode);
- } put_user_catch(err);
+ /* Create the ucontext. */
+ unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault);
+ unsafe_put_user(0, &frame->uc.uc_link, Efault);
+ unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
+ unsafe_put_user(0, &frame->uc.uc__pad0, Efault);
+ restorer = ksig->ka.sa.sa_restorer;
+ unsafe_put_user(restorer, (unsigned long __user *)&frame->pretcode, Efault);
+ user_access_end();
err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
regs, set->sig[0]);
@@ -582,6 +580,11 @@ static int x32_setup_rt_frame(struct ksignal *ksig,
#endif /* CONFIG_X86_X32_ABI */
return 0;
+#ifdef CONFIG_X86_X32_ABI
+Efault:
+ user_access_end();
+ return -EFAULT;
+#endif
}
/*
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 11083d84eb23..224ecb4fffd4 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -483,12 +483,13 @@ extern void __user *compat_alloc_user_space(unsigned long len);
int compat_restore_altstack(const compat_stack_t __user *uss);
int __compat_save_altstack(compat_stack_t __user *, unsigned long);
-#define compat_save_altstack_ex(uss, sp) do { \
+#define unsafe_compat_save_altstack(uss, sp, label) do { \
compat_stack_t __user *__uss = uss; \
struct task_struct *t = current; \
- put_user_ex(ptr_to_compat((void __user *)t->sas_ss_sp), &__uss->ss_sp); \
- put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \
- put_user_ex(t->sas_ss_size, &__uss->ss_size); \
+ unsafe_put_user(ptr_to_compat((void __user *)t->sas_ss_sp), \
+ &__uss->ss_sp, label); \
+ unsafe_put_user(t->sas_ss_flags, &__uss->ss_flags, label); \
+ unsafe_put_user(t->sas_ss_size, &__uss->ss_size, label); \
if (t->sas_ss_flags & SS_AUTODISARM) \
sas_ss_reset(t); \
} while (0);
--
2.11.0
next prev parent reply other threads:[~2020-03-27 2:32 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-23 18:36 [RFC][PATCHSET] x86 uaccess cleanups Al Viro
2020-03-23 18:37 ` [RFC][PATCH 01/22] x86 user stack frame reads: switch to explicit __get_user() Al Viro
2020-03-23 18:37 ` [RFC][PATCH 02/22] x86 kvm page table walks: " Al Viro
2020-03-23 18:38 ` [RFC][PATCH 03/22] x86: switch sigframe sigset handling to explict __get_user()/__put_user() Al Viro
2020-03-23 18:38 ` [RFC][PATCH 04/22] x86: get rid of small constant size cases in raw_copy_{to,from}_user() Al Viro
2020-03-23 18:38 ` [RFC][PATCH 05/22] vm86: get rid of get_user_ex() use Al Viro
2020-03-23 18:38 ` [RFC][PATCH 06/22] x86: get rid of get_user_ex() in ia32_restore_sigcontext() Al Viro
2020-03-23 18:38 ` [RFC][PATCH 07/22] x86: get rid of get_user_ex() in restore_sigcontext() Al Viro
2020-03-23 18:38 ` [RFC][PATCH 08/22] x86: kill get_user_{try,catch,ex} Al Viro
2020-03-23 18:38 ` [RFC][PATCH 09/22] x86: switch save_v86_state() to unsafe_put_user() Al Viro
2020-03-23 18:38 ` [RFC][PATCH 10/22] x86: switch setup_sigcontext() " Al Viro
2020-03-23 18:38 ` [RFC][PATCH 11/22] x86: switch ia32_setup_sigcontext() " Al Viro
2020-03-23 18:38 ` [RFC][PATCH 12/22] x86: get rid of put_user_try in {ia32,x32}_setup_rt_frame() Al Viro
2020-03-23 18:38 ` [RFC][PATCH 13/22] x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers Al Viro
2020-03-23 18:53 ` Linus Torvalds
2020-03-23 21:42 ` Al Viro
2020-03-23 18:38 ` [RFC][PATCH 14/22] x86: ia32_setup_frame(): consolidate uaccess areas Al Viro
2020-03-23 18:38 ` [RFC][PATCH 15/22] x86: ia32_setup_rt_frame(): " Al Viro
2020-03-23 18:38 ` [RFC][PATCH 16/22] x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit) Al Viro
2020-03-23 18:38 ` [RFC][PATCH 17/22] x86: setup_sigcontext(): list user_access_{begin,end}() into callers Al Viro
2020-03-23 18:56 ` Linus Torvalds
2020-03-23 18:38 ` [RFC][PATCH 18/22] x86: __setup_frame(): consolidate uaccess areas Al Viro
2020-03-23 18:38 ` [RFC][PATCH 19/22] x86: __setup_rt_frame(): " Al Viro
2020-03-23 18:38 ` [RFC][PATCH 20/22] x86: x32_setup_rt_frame(): " Al Viro
2020-03-23 18:38 ` [RFC][PATCH 21/22] x86: unsafe_put_... macros for sigcontext and sigmask Al Viro
2020-03-23 18:38 ` [RFC][PATCH 22/22] kill uaccess_try() Al Viro
2020-03-24 15:15 ` [RFC][PATCH 01/22] x86 user stack frame reads: switch to explicit __get_user() Peter Zijlstra
2020-03-28 10:48 ` Ingo Molnar
2020-03-28 11:59 ` Al Viro
2020-03-29 9:26 ` Ingo Molnar
2020-03-29 16:50 ` Andy Lutomirski
2020-03-29 17:05 ` Linus Torvalds
2020-03-29 17:41 ` David Laight
2020-03-29 17:56 ` Linus Torvalds
2020-03-29 18:03 ` David Laight
2020-03-29 18:16 ` Linus Torvalds
2020-03-29 18:32 ` David Laight
2020-03-29 18:55 ` Linus Torvalds
2020-03-29 21:21 ` Andy Lutomirski
2020-03-29 22:06 ` Linus Torvalds
2020-03-29 22:12 ` Linus Torvalds
2020-03-29 18:16 ` Al Viro
2020-03-29 18:19 ` Linus Torvalds
2020-03-29 17:57 ` Al Viro
2020-03-30 15:54 ` David Laight
2020-03-23 19:16 ` [RFC][PATCHSET] x86 uaccess cleanups Linus Torvalds
2020-03-27 2:24 ` [RFC][PATCHSET v2] " Al Viro
2020-03-27 2:26 ` Al Viro
2020-03-27 2:30 ` Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 01/22] x86 user stack frame reads: switch to explicit __get_user() Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 02/22] x86 kvm page table walks: " Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 03/22] x86: switch sigframe sigset handling to explict __get_user()/__put_user() Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 04/22] x86: get rid of small constant size cases in raw_copy_{to,from}_user() Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 05/22] vm86: get rid of get_user_ex() use Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 06/22] x86: get rid of get_user_ex() in ia32_restore_sigcontext() Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 07/22] x86: get rid of get_user_ex() in restore_sigcontext() Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 08/22] x86: kill get_user_{try,catch,ex} Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 09/22] x86: switch save_v86_state() to unsafe_put_user() Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 10/22] x86: switch setup_sigcontext() " Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 11/22] x86: switch ia32_setup_sigcontext() " Al Viro
2020-03-27 2:31 ` Al Viro [this message]
2020-03-27 2:31 ` [RFC][PATCH v2 13/22] x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 14/22] x86: ia32_setup_frame(): consolidate uaccess areas Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 15/22] x86: ia32_setup_rt_frame(): " Al Viro
2020-03-27 2:31 ` [RFC][PATCH v2 16/22] x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit) Al Viro
2020-03-27 2:32 ` [RFC][PATCH v2 17/22] x86: setup_sigcontext(): list user_access_{begin,end}() into callers Al Viro
2020-03-27 2:32 ` [RFC][PATCH v2 18/22] x86: __setup_frame(): consolidate uaccess areas Al Viro
2020-03-27 2:32 ` [RFC][PATCH v2 19/22] x86: __setup_rt_frame(): " Al Viro
2020-03-27 2:32 ` [RFC][PATCH v2 20/22] x86: x32_setup_rt_frame(): " Al Viro
2020-03-27 2:32 ` [RFC][PATCH v2 21/22] x86: unsafe_put-style macro for sigmask Al Viro
2020-03-27 2:32 ` [RFC][PATCH v2 22/22] kill uaccess_try() Al Viro
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