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Remove PAGE_RESERVED

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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>
This commit is contained in:
Paul Brook 2010-05-05 16:32:59 +01:00
parent 048d179f20
commit 2e9a5713f0
4 changed files with 5 additions and 54 deletions
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3
cpu-all.h
View File

@ -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);

31
exec.c
View File

@ -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));
}

6
linux-user/elfload.c
View File

@ -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);
}

19
linux-user/mmap.c
View File

@ -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) &&