From 2e9a5713f0567fffaa3518f495b8d16a2b74f84a Mon Sep 17 00:00:00 2001
From: Paul Brook <paul@codesourcery.com>
Date: Wed, 5 May 2010 16:32:59 +0100
Subject: [PATCH] Remove PAGE_RESERVED
The usermode PAGE_RESERVED code is not required by the current mmap
implementation, and is already broken when guest_base != 0.
Unfortunately the bsd emulation still uses the old mmap implementation,
so we can't rip it out altogether.
Signed-off-by: Paul Brook <paul@codesourcery.com>
---
cpu-all.h | 3 +++
exec.c | 31 ++-----------------------------
linux-user/elfload.c | 6 ------
linux-user/mmap.c | 19 -------------------
4 files changed, 5 insertions(+), 54 deletions(-)
diff --git a/cpu-all.h b/cpu-all.h
index 7b1594cdf8..52a1817bd2 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -742,7 +742,10 @@ extern unsigned long qemu_host_page_mask;
/* original state of the write flag (used when tracking self-modifying
code */
#define PAGE_WRITE_ORG 0x0010
+#if defined(CONFIG_BSD) && defined(CONFIG_USER_ONLY)
+/* FIXME: Code that sets/uses this is broken and needs to go away. */
#define PAGE_RESERVED 0x0020
+#endif
#if defined(CONFIG_USER_ONLY)
void page_dump(FILE *f);
diff --git a/exec.c b/exec.c
index 14d1fd733d..95b92f7f63 100644
--- a/exec.c
+++ b/exec.c
@@ -288,7 +288,7 @@ static void page_init(void)
qemu_host_page_bits++;
qemu_host_page_mask = ~(qemu_host_page_size - 1);
-#if !defined(_WIN32) && defined(CONFIG_USER_ONLY)
+#if defined(CONFIG_BSD) && defined(CONFIG_USER_ONLY)
{
#ifdef HAVE_KINFO_GETVMMAP
struct kinfo_vmentry *freep;
@@ -324,11 +324,7 @@ static void page_init(void)
last_brk = (unsigned long)sbrk(0);
-#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
f = fopen("/compat/linux/proc/self/maps", "r");
-#else
- f = fopen("/proc/self/maps", "r");
-#endif
if (f) {
mmap_lock();
@@ -365,24 +361,11 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc)
int i;
#if defined(CONFIG_USER_ONLY)
- /* We can't use qemu_malloc because it may recurse into a locked mutex.
- Neither can we record the new pages we reserve while allocating a
- given page because that may recurse into an unallocated page table
- entry. Stuff the allocations we do make into a queue and process
- them after having completed one entire page table allocation. */
-
- unsigned long reserve[2 * (V_L1_SHIFT / L2_BITS)];
- int reserve_idx = 0;
-
+ /* We can't use qemu_malloc because it may recurse into a locked mutex. */
# define ALLOC(P, SIZE) \
do { \
P = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, \
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); \
- if (h2g_valid(P)) { \
- reserve[reserve_idx] = h2g(P); \
- reserve[reserve_idx + 1] = SIZE; \
- reserve_idx += 2; \
- } \
} while (0)
#else
# define ALLOC(P, SIZE) \
@@ -417,16 +400,6 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc)
}
#undef ALLOC
-#if defined(CONFIG_USER_ONLY)
- for (i = 0; i < reserve_idx; i += 2) {
- unsigned long addr = reserve[i];
- unsigned long len = reserve[i + 1];
-
- page_set_flags(addr & TARGET_PAGE_MASK,
- TARGET_PAGE_ALIGN(addr + len),
- PAGE_RESERVED);
- }
-#endif
return pd + (index & (L2_SIZE - 1));
}
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 4d3dd89b2b..13f63cf77e 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -2159,12 +2159,6 @@ static int vma_walker(void *priv, abi_ulong start, abi_ulong end,
{
struct mm_struct *mm = (struct mm_struct *)priv;
- /*
- * Don't dump anything that qemu has reserved for internal use.
- */
- if (flags & PAGE_RESERVED)
- return (0);
-
vma_add_mapping(mm, start, end, flags);
return (0);
}
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 46923c707c..9c062e7078 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -85,14 +85,6 @@ void *qemu_vmalloc(size_t size)
/* Use map and mark the pages as used. */
p = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-
- if (h2g_valid(p)) {
- /* Allocated region overlaps guest address space. This may recurse. */
- abi_ulong addr = h2g(p);
- page_set_flags(addr & TARGET_PAGE_MASK, TARGET_PAGE_ALIGN(addr + size),
- PAGE_RESERVED);
- }
-
mmap_unlock();
return p;
}
@@ -484,9 +476,6 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
}
start = h2g(host_start);
} else {
- int flg;
- target_ulong addr;
-
if (start & ~TARGET_PAGE_MASK) {
errno = EINVAL;
goto fail;
@@ -504,14 +493,6 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
goto fail;
}
- for(addr = real_start; addr < real_end; addr += TARGET_PAGE_SIZE) {
- flg = page_get_flags(addr);
- if (flg & PAGE_RESERVED) {
- errno = ENXIO;
- goto fail;
- }
- }
-
/* worst case: we cannot map the file because the offset is not
aligned, so we read it */
if (!(flags & MAP_ANONYMOUS) &&
--
2.30.2