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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Michael Ellerman <mpe@ellerman.id.au>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 188/411] powerpc/64: Only WARN if __pa()/__va() called with bad addresses
Date:   Mon, 13 Jun 2022 12:07:41 +0200
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From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit c4bce84d0bd3f396f702d69be2e92bbd8af97583 ]

We added checks to __pa() / __va() to ensure they're only called with
appropriate addresses. But using BUG_ON() is too strong, it means
virt_addr_valid() will BUG when DEBUG_VIRTUAL is enabled.

Instead switch them to warnings, arm64 does the same.

Fixes: 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va and __pa addresses")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220406145802.538416-5-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/page.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 0d8f9246ce15..d92353a96f81 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -216,6 +216,9 @@ static inline bool pfn_valid(unsigned long pfn)
 #define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET)
 #else
 #ifdef CONFIG_PPC64
+
+#define VIRTUAL_WARN_ON(x)	WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && (x))
+
 /*
  * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET
  * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit.
@@ -223,13 +226,13 @@ static inline bool pfn_valid(unsigned long pfn)
  */
 #define __va(x)								\
 ({									\
-	VIRTUAL_BUG_ON((unsigned long)(x) >= PAGE_OFFSET);		\
+	VIRTUAL_WARN_ON((unsigned long)(x) >= PAGE_OFFSET);		\
 	(void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET);	\
 })
 
 #define __pa(x)								\
 ({									\
-	VIRTUAL_BUG_ON((unsigned long)(x) < PAGE_OFFSET);		\
+	VIRTUAL_WARN_ON((unsigned long)(x) < PAGE_OFFSET);		\
 	(unsigned long)(x) & 0x0fffffffffffffffUL;			\
 })
 
-- 
2.35.1