74f46db5e6
Copy from IBS home:uli_suse:branches:SUSE:Factory:Head/qemu based on submit request 2136 from user uli_suse OBS-URL: https://build.opensuse.org/request/show/2136 OBS-URL: https://build.opensuse.org/package/show/openSUSE:Factory/qemu?expand=0&rev=34
126 lines
4.0 KiB
Diff
126 lines
4.0 KiB
Diff
From d7f01e455acae19ef780e29417ffba50ca90ffde Mon Sep 17 00:00:00 2001
|
|
From: Kirill A. Shutemov <kirill@shutemov.name>
|
|
Date: Wed, 17 Jun 2009 15:14:43 +0200
|
|
Subject: [PATCH 19/33] Rewrite mmap_find_vma() to work fine on 64-bit hosts with 32-bit targets
|
|
|
|
From: Kirill A. Shutemov <kirill@shutemov.name>
|
|
|
|
qemu's page table can be incomple if /proc/self/maps is unavailable or
|
|
host allocating a memory with mmap(), so we can't use it to find free
|
|
memory area.
|
|
|
|
New version mmap_find_vma() uses mmap() without MAP_FIXED to find free
|
|
memory.
|
|
|
|
From: Kirill A. Shutemov <kirill@shutemov.name>
|
|
|
|
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
|
|
Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
|
|
---
|
|
linux-user/mmap.c | 79 +++++++++++++++++++++++++++++------------------------
|
|
1 files changed, 43 insertions(+), 36 deletions(-)
|
|
|
|
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
|
|
index 9ca8f6f..8d94783 100644
|
|
--- a/linux-user/mmap.c
|
|
+++ b/linux-user/mmap.c
|
|
@@ -277,52 +277,59 @@ static abi_ulong mmap_next_start = 0x40000000;
|
|
|
|
unsigned long last_brk;
|
|
|
|
-/* find a free memory area of size 'size'. The search starts at
|
|
- 'start'. If 'start' == 0, then a default start address is used.
|
|
- Return -1 if error.
|
|
-*/
|
|
-/* page_init() marks pages used by the host as reserved to be sure not
|
|
- to use them. */
|
|
+/*
|
|
+ * Find and reserve a free memory area of size 'size'. The search
|
|
+ * starts at 'start'.
|
|
+ * It must be called with mmap_lock() held.
|
|
+ * Return -1 if error.
|
|
+ */
|
|
abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size)
|
|
{
|
|
- abi_ulong addr, addr1, addr_start;
|
|
- int prot;
|
|
- unsigned long new_brk;
|
|
-
|
|
- new_brk = (unsigned long)sbrk(0);
|
|
- if (last_brk && last_brk < new_brk && last_brk == (target_ulong)last_brk) {
|
|
- /* This is a hack to catch the host allocating memory with brk().
|
|
- If it uses mmap then we loose.
|
|
- FIXME: We really want to avoid the host allocating memory in
|
|
- the first place, and maybe leave some slack to avoid switching
|
|
- to mmap. */
|
|
- page_set_flags(last_brk & TARGET_PAGE_MASK,
|
|
- TARGET_PAGE_ALIGN(new_brk),
|
|
- PAGE_RESERVED);
|
|
- }
|
|
- last_brk = new_brk;
|
|
+ void *ptr;
|
|
+ abi_ulong addr;
|
|
|
|
size = HOST_PAGE_ALIGN(size);
|
|
- start = start & qemu_host_page_mask;
|
|
+ start &= qemu_host_page_mask;
|
|
+
|
|
+ /* If 'start' == 0, then a default start address is used. */
|
|
+ if (start == 0)
|
|
+ start = mmap_next_start;
|
|
+
|
|
addr = start;
|
|
- if (addr == 0)
|
|
- addr = mmap_next_start;
|
|
- addr_start = addr;
|
|
+
|
|
for(;;) {
|
|
- prot = 0;
|
|
- for(addr1 = addr; addr1 < (addr + size); addr1 += TARGET_PAGE_SIZE) {
|
|
- prot |= page_get_flags(addr1);
|
|
- }
|
|
- if (prot == 0)
|
|
+ /*
|
|
+ * Reserve needed memory area to avoid a race.
|
|
+ * It should be discarded using:
|
|
+ * - mmap() with MAP_FIXED flag
|
|
+ * - mremap() with MREMAP_FIXED flag
|
|
+ * - shmat() with SHM_REMAP flag
|
|
+ */
|
|
+ ptr = mmap((void *)(unsigned long)addr, size, PROT_NONE,
|
|
+ MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE, -1, 0);
|
|
+
|
|
+ /* ENOMEM, if host address space has no memory */
|
|
+ if (ptr == MAP_FAILED)
|
|
+ return (abi_ulong)-1;
|
|
+
|
|
+ /* If address fits target address space we've found what we need */
|
|
+ if ((unsigned long)ptr + size - 1 <= (abi_ulong)-1)
|
|
break;
|
|
+
|
|
+ /* Unmap and try again with new page */
|
|
+ munmap(ptr, size);
|
|
addr += qemu_host_page_size;
|
|
- /* we found nothing */
|
|
- if (addr == addr_start)
|
|
+
|
|
+ /* ENOMEM if we check whole of target address space */
|
|
+ if (addr == start)
|
|
return (abi_ulong)-1;
|
|
}
|
|
- if (start == 0)
|
|
- mmap_next_start = addr + size;
|
|
- return addr;
|
|
+
|
|
+ /* Update default start address */
|
|
+ if (start == mmap_next_start)
|
|
+ mmap_next_start = (unsigned long)ptr + size;
|
|
+
|
|
+ return h2g(ptr);
|
|
}
|
|
|
|
#define SNDRV_PCM_MMAP_OFFSET_STATUS 0x80000000
|
|
--
|
|
1.6.2.1
|
|
|