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Date: Fri, 8 Oct 2021 17:40:34 +0200
From: Christophe Leroy <christophe.leroy@...roup.eu>
To: Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Michael Ellerman <mpe@...erman.id.au>
Cc: Christophe Leroy <christophe.leroy@...roup.eu>,
linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH v2 06/16] powerpc/kuap: Add kuap_lock()
Add kuap_lock() and call it when entering interrupts from user.
It is called kuap_lock() as it is similar to kuap_save_and_lock()
without the save.
However book3s/32 already have a kuap_lock(). Rename it
kuap_lock_addr().
Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
---
arch/powerpc/include/asm/book3s/32/kup.h | 12 ++++++++----
arch/powerpc/include/asm/interrupt.h | 5 ++++-
arch/powerpc/include/asm/kup.h | 9 +++++++++
arch/powerpc/include/asm/nohash/32/kup-8xx.h | 4 ++++
arch/powerpc/kernel/interrupt.c | 2 ++
5 files changed, 27 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index e273a6d3b6ad..b61a48550e59 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -60,7 +60,7 @@ static inline void kuap_unlock_all(void)
void kuap_lock_all_ool(void);
void kuap_unlock_all_ool(void);
-static inline void kuap_lock(unsigned long addr, bool ool)
+static inline void kuap_lock_addr(unsigned long addr, bool ool)
{
if (likely(addr != KUAP_ALL))
kuap_lock_one(addr);
@@ -80,6 +80,10 @@ static inline void kuap_unlock(unsigned long addr, bool ool)
kuap_unlock_all_ool();
}
+static inline void __kuap_lock(void)
+{
+}
+
static inline void __kuap_save_and_lock(struct pt_regs *regs)
{
unsigned long kuap = current->thread.kuap;
@@ -89,7 +93,7 @@ static inline void __kuap_save_and_lock(struct pt_regs *regs)
return;
current->thread.kuap = KUAP_NONE;
- kuap_lock(kuap, false);
+ kuap_lock_addr(kuap, false);
}
static inline void kuap_user_restore(struct pt_regs *regs)
@@ -142,7 +146,7 @@ static __always_inline void __prevent_user_access(unsigned long dir)
return;
current->thread.kuap = KUAP_NONE;
- kuap_lock(kuap, true);
+ kuap_lock_addr(kuap, true);
}
static inline unsigned long __prevent_user_access_return(void)
@@ -151,7 +155,7 @@ static inline unsigned long __prevent_user_access_return(void)
if (flags != KUAP_NONE) {
current->thread.kuap = KUAP_NONE;
- kuap_lock(flags, true);
+ kuap_lock_addr(flags, true);
}
return flags;
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 3bbca1fbbe1e..ae719e200c80 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -140,9 +140,12 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
trace_hardirqs_off();
if (user_mode(regs))
- account_cpu_user_entry();
+ kuap_lock();
else
kuap_save_and_lock(regs);
+
+ if (user_mode(regs))
+ account_cpu_user_entry();
#endif
#ifdef CONFIG_PPC64
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 7f0d614c5b8b..2e0c2df21b3b 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -52,6 +52,7 @@ __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
}
static inline void __kuap_assert_locked(void) { }
+static inline void __kuap_lock(void) { }
static inline void __kuap_save_and_lock(struct pt_regs *regs) { }
static inline void kuap_user_restore(struct pt_regs *regs) { }
static inline void __kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
@@ -94,6 +95,14 @@ static __always_inline void kuap_assert_locked(void)
}
#ifdef CONFIG_PPC32
+static __always_inline void kuap_lock(void)
+{
+ if (kuap_is_disabled())
+ return;
+
+ __kuap_lock();
+}
+
static __always_inline void kuap_save_and_lock(struct pt_regs *regs)
{
if (kuap_is_disabled())
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 37fe4b32b658..c44d97751723 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -20,6 +20,10 @@ static __always_inline bool kuap_is_disabled(void)
return static_branch_unlikely(&disable_kuap_key);
}
+static inline void __kuap_lock(void)
+{
+}
+
static inline void __kuap_save_and_lock(struct pt_regs *regs)
{
regs->kuap = mfspr(SPRN_MD_AP);
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index 0d12aa66e1f9..dc56a514df0a 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -81,6 +81,8 @@ notrace long system_call_exception(long r3, long r4, long r5,
{
syscall_fn f;
+ kuap_lock();
+
regs->orig_gpr3 = r3;
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
--
2.31.1
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