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Revert "stdlib: Support malloc-managed environ arrays for compatibility"

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This reverts commit b62759db04.

Reason for revert: Incompatible with “env -i” and coreutils (bug 32588).

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
This commit is contained in:
Florian Weimer
2025-01-24 08:04:23 +01:00
parent b62759db04
commit 36fcdfbbc5
7 changed files with 32 additions and 104 deletions
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64
stdlib/setenv.c
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@@ -191,52 +191,52 @@ __add_to_environ (const char *name, const char *value, const char *combined,
ep[1] = NULL;
else
{
/* We cannot use __environ as is and need a larger allocation. */
/* We cannot use __environ as is and need to copy over the
__environ contents into an array managed via
__environ_array_list. */
if (start_environ == __environ_startup
|| __environ_is_from_array_list (start_environ))
struct environ_array *target_array;
if (__environ_array_list != NULL
&& required_size <= __environ_array_list->allocated)
/* Existing array has enough room. Contents is copied below. */
target_array = __environ_array_list;
else
{
/* Allocate a new array, managed in the list. */
struct environ_array *target_array
= __environ_new_array (required_size);
/* Allocate a new array. */
target_array = __environ_new_array (required_size);
if (target_array == NULL)
{
UNLOCK;
return -1;
}
result_environ = &target_array->array[0];
}
/* Copy over the __environ array contents. This code
handles the case start_environ == ep == NULL, too. */
size_t i;
for (i = 0; start_environ + i < ep; ++i)
/* Regular store because unless there has been direct
manipulation of the environment, target_array is still
a private copy. */
result_environ[i] = atomic_load_relaxed (start_environ + i);
}
else
{
/* Otherwise the application installed its own pointer.
Historically, this pointer was managed using realloc.
Continue doing so. This disables multi-threading
support. */
result_environ = __libc_reallocarray (start_environ,
required_size,
sizeof (*result_environ));
if (result_environ == NULL)
{
UNLOCK;
return -1;
}
}
/* Copy over the __environ array contents. This forward
copy slides backwards part of the array if __environ
points into target_array->array. This happens if an
application makes an assignment like:
environ = &environ[1];
The forward copy avoids clobbering values that still
needing copying. This code handles the case
start_environ == ep == NULL, too. */
size_t i;
for (i = 0; start_environ + i < ep; ++i)
/* Regular store because unless there has been direct
manipulation of the environment, target_array is still
a private copy. */
target_array->array[i] = atomic_load_relaxed (start_environ + i);
/* This is the new place where we should add the element. */
ep = result_environ + (required_size - 2);
ep = target_array->array + i;
/* Add the null terminator in case there was a pointer there
previously. */
ep[1] = NULL;
/* And __environ should be repointed to our array. */
result_environ = &target_array->array[0];
}
}