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authorRichard Henderson <richard.henderson@linaro.org>2023-07-07 21:40:46 +0100
committerRichard Henderson <richard.henderson@linaro.org>2023-07-15 08:02:32 +0100
commit4c13048e02d93985320e4a9651dc29577ba53f0e (patch)
tree330f119ba2721161ef032f327d2100307fbbb5a2 /linux-user
parentf12294b5bd214232eb0b4be87fed35519f006182 (diff)
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linux-user: Use page_find_range_empty for mmap_find_vma_reserved
Use the interval tree to find empty space, rather than probing each page in turn. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20230707204054.8792-19-richard.henderson@linaro.org>
Diffstat (limited to 'linux-user')
-rw-r--r--linux-user/mmap.c52
1 files changed, 6 insertions, 46 deletions
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index c4b2515..738b9b7 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -318,55 +318,15 @@ unsigned long last_brk;
static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size,
abi_ulong align)
{
- abi_ulong addr, end_addr, incr = qemu_host_page_size;
- int prot;
- bool looped = false;
-
- if (size > reserved_va) {
- return (abi_ulong)-1;
- }
-
- /* Note that start and size have already been aligned by mmap_find_vma. */
+ target_ulong ret;
- end_addr = start + size;
- /*
- * Start at the top of the address space, ignoring the last page.
- * If reserved_va == UINT32_MAX, then end_addr wraps to 0,
- * throwing the rest of the calculations off.
- * TODO: rewrite using last_addr instead.
- * TODO: use the interval tree instead of probing every page.
- */
- if (start > reserved_va - size) {
- end_addr = ((reserved_va - size) & -align) + size;
- looped = true;
+ ret = page_find_range_empty(start, reserved_va, size, align);
+ if (ret == -1 && start > mmap_min_addr) {
+ /* Restart at the beginning of the address space. */
+ ret = page_find_range_empty(mmap_min_addr, start - 1, size, align);
}
- /* Search downward from END_ADDR, checking to see if a page is in use. */
- addr = end_addr;
- while (1) {
- addr -= incr;
- if (addr > end_addr) {
- if (looped) {
- /* Failure. The entire address space has been searched. */
- return (abi_ulong)-1;
- }
- /* Re-start at the top of the address space (see above). */
- addr = end_addr = ((reserved_va - size) & -align) + size;
- looped = true;
- } else {
- prot = page_get_flags(addr);
- if (prot) {
- /* Page in use. Restart below this page. */
- addr = end_addr = ((addr - size) & -align) + size;
- } else if (addr && addr + size == end_addr) {
- /* Success! All pages between ADDR and END_ADDR are free. */
- if (start == mmap_next_start) {
- mmap_next_start = addr;
- }
- return addr;
- }
- }
- }
+ return ret;
}
/*