[PATCH 5.17 545/772] powerpc/64: Only WARN if __pa()/__va() called with bad addresses

Greg Kroah-Hartman
2022-06-07T21:33:43Z

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 f2c5c26869f1..03ae544eb6cc 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) ((phys_addr_t)(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