[PATCH 15/16] sparc: mm: Support MAP_BELOW_HINT
From: Charlie Jenkins <hidden>
Date: 2024-08-28 05:50:18
Also in:
linux-arch, linux-kselftest, linux-mips, linux-mm, linux-riscv, linux-s390, linux-sh, lkml, loongarch, sparclinux
Subsystem:
sparc + ultrasparc (sparc/sparc64), the rest · Maintainers:
"David S. Miller", Andreas Larsson, Linus Torvalds
Add support for MAP_BELOW_HINT to mmap by restricting high_limit to addr when the flag is enabled. Signed-off-by: Charlie Jenkins <redacted> --- 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); }
--
2.45.0