Add support for MAP_BELOW_HINT to mmap by restricting high_limit to addr when the flag is enabled.
Signed-off-by: Charlie Jenkins charlie@rivosinc.com --- arch/sparc/kernel/sys_sparc_64.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c index d9c3b34ca744..b9ce9988551a 100644 --- a/arch/sparc/kernel/sys_sparc_64.c +++ b/arch/sparc/kernel/sys_sparc_64.c @@ -129,6 +129,8 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi info.length = len; info.low_limit = TASK_UNMAPPED_BASE; info.high_limit = min(task_size, VA_EXCLUDE_START); + if (flags & MAP_BELOW_HINT) + info.high_limit = MIN(info.high_limit, addr + len); info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; info.align_offset = pgoff << PAGE_SHIFT; addr = vm_unmapped_area(&info); @@ -137,6 +139,8 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi VM_BUG_ON(addr != -ENOMEM); info.low_limit = VA_EXCLUDE_END; info.high_limit = task_size; + if (flags & MAP_BELOW_HINT) + info.high_limit = MIN(info.high_limit, addr + len); addr = vm_unmapped_area(&info); }
@@ -192,6 +196,8 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, info.length = len; info.low_limit = PAGE_SIZE; info.high_limit = mm->mmap_base; + if (flags & MAP_BELOW_HINT) + info.high_limit = MIN(info.high_limit, addr + len); info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; info.align_offset = pgoff << PAGE_SHIFT; addr = vm_unmapped_area(&info); @@ -207,6 +213,8 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, info.flags = 0; info.low_limit = TASK_UNMAPPED_BASE; info.high_limit = STACK_TOP32; + if (flags & MAP_BELOW_HINT) + info.high_limit = MIN(info.high_limit, addr + len); addr = vm_unmapped_area(&info); }