@@ -13,22 +13,17 @@
#include <vdso/processor.h>
#include <asm/ptrace.h>
+#include <asm/mman.h>
-/*
- * addr is a hint to the maximum userspace address that mmap should provide, so
- * this macro needs to return the largest address space available so that
- * mmap_end < addr, being mmap_end the top of that address space.
- * See Documentation/arch/riscv/vm-layout.rst for more details.
- */
#define arch_get_mmap_end(addr, len, flags) \
({ \
unsigned long mmap_end; \
typeof(addr) _addr = (addr); \
- if ((_addr) == 0 || is_compat_task() || \
- ((_addr + len) > BIT(VA_BITS - 1))) \
+ if (((_addr + len) > DEFAULT_MAP_WINDOW) || \
+ ((flags) & MAP_FIXED)) \
mmap_end = STACK_TOP_MAX; \
else \
- mmap_end = (_addr + len); \
+ mmap_end = DEFAULT_MAP_WINDOW; \
mmap_end; \
})
@@ -38,11 +33,10 @@
typeof(addr) _addr = (addr); \
typeof(base) _base = (base); \
unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base); \
- if ((_addr) == 0 || is_compat_task() || \
- ((_addr + len) > BIT(VA_BITS - 1))) \
- mmap_base = (_base); \
+ if ((_addr + len) > DEFAULT_MAP_WINDOW) \
+ mmap_base = (STACK_TOP_MAX - rnd_gap); \
else \
- mmap_base = (_addr + len) - rnd_gap; \
+ mmap_base = (_base); \
mmap_base; \
})
This patch reverted the meaning of the addr parameter in the mmap syscall change from the previous commit b5b4287accd7 ("riscv: mm: Use hint address in mmap if available") from patch[1] which treats hint addr + size as the upper bound of the mmap return address. Result in ENOMEM error caused when hint address + size is not big enough. Thus, this patch makes the behavior of mmap syscall to align with x86, arm64, powerpc by only limiting the address space to DEFAULT_MAP_WINDOW which is defined as not larger than 47-bit. If a user program wants to use sv57 address space, it can use mmap with a hint address larger than BIT(47) as it is already documented in x86 and arm64. [1] https://lore.kernel.org/linux-riscv/20240130-use_mmap_hint_address-v3-0-8a655cfa8bcb@rivosinc.com/ Signed-off-by: Yangyu Chen <cyy@cyyself.name> --- arch/riscv/include/asm/processor.h | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-)