[PATCH 6.6.y 2/2] riscv: mm: Do not restrict mmap address based on hint

Vivian Wang wangruikang at iscas.ac.cn
Wed Oct 8 00:50:17 PDT 2025


From: Charlie Jenkins <charlie at rivosinc.com>

[ Upstream commit 2116988d5372aec51f8c4fb85bf8e305ecda47a0 ]

The hint address should not forcefully restrict the addresses returned
by mmap as this causes mmap to report ENOMEM when there is memory still
available.

Signed-off-by: Charlie Jenkins <charlie at rivosinc.com>
Fixes: b5b4287accd7 ("riscv: mm: Use hint address in mmap if available")
Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
Closes: https://lore.kernel.org/linux-kernel/ZbxTNjQPFKBatMq+@ghost/T/#mccb1890466bf5a488c9ce7441e57e42271895765
Link: https://lore.kernel.org/r/20240826-riscv_mmap-v1-3-cd8962afe47f@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer at rivosinc.com>
[ Adjust removed lines ]
Signed-off-by: Vivian Wang <wangruikang at iscas.ac.cn>
Tested-by: Han Gao <rabenda.cn at gmail.com>
---
 arch/riscv/include/asm/processor.h | 22 ++--------------------
 1 file changed, 2 insertions(+), 20 deletions(-)

diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 938aef30dfb42ee477b7c59b5d2afc3871d8004d..4747277983ad1a2a9666c03a4e69758f56d22dbc 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -15,30 +15,12 @@
 
 #define arch_get_mmap_end(addr, len, flags)			\
 ({								\
-	unsigned long mmap_end;					\
-	typeof(addr) _addr = (addr);				\
-	if ((_addr) == 0 ||					\
-	    (IS_ENABLED(CONFIG_COMPAT) && is_compat_task()) ||	\
-	    ((_addr + len) > BIT(VA_BITS - 1)))			\
-		mmap_end = STACK_TOP_MAX;			\
-	else							\
-		mmap_end = (_addr + len);			\
-	mmap_end;						\
+	STACK_TOP_MAX;						\
 })
 
 #define arch_get_mmap_base(addr, base)				\
 ({								\
-	unsigned long mmap_base;				\
-	typeof(addr) _addr = (addr);				\
-	typeof(base) _base = (base);				\
-	unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base);	\
-	if ((_addr) == 0 ||					\
-	    (IS_ENABLED(CONFIG_COMPAT) && is_compat_task()) ||	\
-	    ((_addr + len) > BIT(VA_BITS - 1)))			\
-		mmap_base = (_base);				\
-	else							\
-		mmap_base = (_addr + len) - rnd_gap;		\
-	mmap_base;						\
+	base;							\
 })
 
 #ifdef CONFIG_64BIT

-- 
2.50.1




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