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linux-user: Split out mmap_h_eq_g 

Move the MAX_FIXED_NOREPLACE check for reserved_va earlier.
Move the computation of host_prot earlier.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20240102015808.132373-22-richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2024-01-02 12:57:56 +11:00
parent 3bfa271e46
commit 68098de90e
1 changed files with 55 additions and 13 deletions
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68
linux-user/mmap.c
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@ -542,6 +542,33 @@ static abi_long mmap_end(abi_ulong start, abi_ulong last,
return start;
}
/*
* Special case host page size == target page size,
* where there are no edge conditions.
*/
static abi_long mmap_h_eq_g(abi_ulong start, abi_ulong len,
int host_prot, int flags, int page_flags,
int fd, off_t offset)
{
void *p, *want_p = g2h_untagged(start);
abi_ulong last;
p = mmap(want_p, len, host_prot, flags, fd, offset);
if (p == MAP_FAILED) {
return -1;
}
/* If the host kernel does not support MAP_FIXED_NOREPLACE, emulate. */
if ((flags & MAP_FIXED_NOREPLACE) && p != want_p) {
do_munmap(p, len);
errno = EEXIST;
return -1;
}
start = h2g(p);
last = start + len - 1;
return mmap_end(start, last, start, last, flags, page_flags);
}
static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
int target_prot, int flags, int page_flags,
int fd, off_t offset)
@ -550,6 +577,7 @@ static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
abi_ulong ret, last, real_start, real_last, retaddr, host_len;
abi_ulong passthrough_start = -1, passthrough_last = 0;
off_t host_offset;
int host_prot;
real_start = start & -host_page_size;
host_offset = offset & -host_page_size;
@ -558,16 +586,33 @@ static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
* For reserved_va, we are in full control of the allocation.
* Find a suitable hole and convert to MAP_FIXED.
*/
if (reserved_va && !(flags & (MAP_FIXED | MAP_FIXED_NOREPLACE))) {
host_len = len + offset - host_offset;
start = mmap_find_vma(real_start, host_len,
MAX(host_page_size, TARGET_PAGE_SIZE));
if (start == (abi_ulong)-1) {
errno = ENOMEM;
return -1;
if (reserved_va) {
if (flags & MAP_FIXED_NOREPLACE) {
/* Validate that the chosen range is empty. */
if (!page_check_range_empty(start, start + len - 1)) {
errno = EEXIST;
return -1;
}
flags = (flags & ~MAP_FIXED_NOREPLACE) | MAP_FIXED;
} else if (!(flags & MAP_FIXED)) {
size_t real_len = len + offset - host_offset;
abi_ulong align = MAX(host_page_size, TARGET_PAGE_SIZE);
start = mmap_find_vma(real_start, real_len, align);
if (start == (abi_ulong)-1) {
errno = ENOMEM;
return -1;
}
start += offset - host_offset;
flags |= MAP_FIXED;
}
start += offset - host_offset;
flags |= MAP_FIXED;
}
host_prot = target_to_host_prot(target_prot);
if (host_page_size == TARGET_PAGE_SIZE) {
return mmap_h_eq_g(start, len, host_prot, flags,
page_flags, fd, offset);
}
/*
@ -603,12 +648,10 @@ static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
if (!(flags & (MAP_FIXED | MAP_FIXED_NOREPLACE))) {
uintptr_t host_start;
int host_prot;
void *p;
host_len = len + offset - host_offset;
host_len = ROUND_UP(host_len, host_page_size);
host_prot = target_to_host_prot(target_prot);
/* Note: we prefer to control the mapping address. */
p = mmap(g2h_untagged(start), host_len, host_prot,
@ -731,8 +774,7 @@ static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
len1 = real_last - real_start + 1;
want_p = g2h_untagged(real_start);
p = mmap(want_p, len1, target_to_host_prot(target_prot),
flags, fd, offset1);
p = mmap(want_p, len1, host_prot, flags, fd, offset1);
if (p != want_p) {
if (p != MAP_FAILED) {
do_munmap(p, len1);