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Add support for 32-bit processes to call supercall #256

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Add support for 32-bit processes to call supercall #256

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4328a3f
add support to 32-bit supercall
ThePedroo Apr 1, 2026
17a555c
add support for reading/writing kstorage from 32-bit process
ThePedroo May 1, 2026
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38 changes: 28 additions & 10 deletions kernel/patch/common/supercall.c
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Original file line number Diff line number Diff line change
Expand Up @@ -247,14 +247,28 @@ static long call_su_set_allow_sctx(char *__user usctx)
return set_all_allow_sctx(buf);
}

static long call_kstorage_read(int gid, long did, void *out_data, int offset, int dlen)
{
return read_kstorage(gid, did, out_data, offset, dlen, true);
struct data_item {
void *data;
int dlen;
int offset;
};

static long call_kstorage_read(int gid, long did, struct data_item *out_data_item)
{
struct data_item *item = memdup_user(out_data_item, sizeof(*item));
if (!item || IS_ERR(item)) return PTR_ERR(item);
long rc = read_kstorage(gid, did, item->data, item->offset, item->dlen, true);
kvfree(item);
return rc;
}

static long call_kstorage_write(int gid, long did, void *data, int offset, int dlen)
static long call_kstorage_write(int gid, long did, struct data_item *in_data_item)
{
return write_kstorage(gid, did, data, offset, dlen, true);
struct data_item *item = memdup_user(in_data_item, sizeof(*item));
if (!item || IS_ERR(item)) return PTR_ERR(item);
long rc = write_kstorage(gid, did, item->data, item->offset, item->dlen, true);
kvfree(item);
return rc;
}

static long call_list_kstorage_ids(int gid, long *ids, int ids_len)
Expand Down Expand Up @@ -311,12 +325,10 @@ static long supercall(int is_key_auth, long cmd, long arg1, long arg2, long arg3
return call_su_get_allow_sctx((char *__user)arg1, (int)arg2);
case SUPERCALL_SU_SET_ALLOW_SCTX:
return call_su_set_allow_sctx((char *__user)arg1);

case SUPERCALL_KSTORAGE_READ:
return call_kstorage_read((int)arg1, (long)arg2, (void *)arg3, (int)((long)arg4 >> 32), (long)arg4 << 32 >> 32);
return call_kstorage_read((int)arg1, (long)arg2, (struct data_item *)arg3);
case SUPERCALL_KSTORAGE_WRITE:
return call_kstorage_write((int)arg1, (long)arg2, (void *)arg3, (int)((long)arg4 >> 32),
(long)arg4 << 32 >> 32);
return call_kstorage_write((int)arg1, (long)arg2, (struct data_item *)arg3);
case SUPERCALL_KSTORAGE_LIST_IDS:
return call_list_kstorage_ids((int)arg1, (long *)arg2, (int)arg3);
case SUPERCALL_KSTORAGE_REMOVE:
Expand Down Expand Up @@ -418,7 +430,13 @@ int supercall_install()

hook_err_t err = hook_syscalln(__NR_supercall, 6, before, 0, 0);
if (err) {
log_boot("install supercall hook error: %d\n", err);
log_boot("install supercall 64-bit hook error: %d\n", err);
rc = err;
goto out;
}
err = hook_compat_syscalln(92, 6, before, 0, 0); // __NR_truncate == __NR_supercall for 32-bit
if (err) {
log_boot("install supercall 32-bit hook error: %d\n", err);
rc = err;
goto out;
}
Expand Down