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Remove broken support for write in emulated mmap

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* Emulated mmap based write without pagefault handling is not
    possible since IO happens outside of call to mmap and data is
    written to mapped memory
    * Potential emulation using userfaultfd() might be possible
This commit is contained in:
Dhruva Krishnamurthy
2020-11-23 10:14:00 -08:00
committed by Edward Thomson
parent c0e16a467d
commit d77c073f09
1 changed files with 6 additions and 5 deletions
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11
src/posix.c
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@@ -239,14 +239,15 @@ int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, off64_t offset
{
GIT_MMAP_VALIDATE(out, len, prot, flags);
out->data = NULL;
out->len = 0;
if ((prot & GIT_PROT_WRITE) && ((flags & GIT_MAP_TYPE) == GIT_MAP_SHARED)) {
git_error_set(GIT_ERROR_OS, "trying to map shared-writeable");
/* writes cannot be emulated without handling pagefaults since write happens by
* writing to mapped memory */
if (prot & GIT_PROT_WRITE) {
git_error_set(GIT_ERROR_OS, "trying to map %s-writeable",
((flags & GIT_MAP_TYPE) == GIT_MAP_SHARED) ? "shared": "private");
return -1;
}
out->len = 0;
out->data = git__malloc(len);
GIT_ERROR_CHECK_ALLOC(out->data);