[lkml]   [2021]   [Dec]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 18/25] selftests/sgx: Introduce dynamic entry point
The test enclave (test_encl.elf) is built with two initialized
Thread Control Structures (TCS) included in the binary. Both TCS are
initialized with the same entry point, encl_entry, that correctly
computes the absolute address of the stack based on the stack of each
TCS that is also built into the binary.

A new TCS can be added dynamically to the enclave and requires to be
initialized with an entry point used to enter the enclave. Since the
existing entry point, encl_entry, assumes that the TCS and its stack
exists at particular offsets within the binary it is not able to handle
a dynamically added TCS and its stack.

Introduce a new entry point, encl_dyn_entry, that initializes the absolute
address of that thread's stack to the address immediately preceding the
TCS itself. It is now possible to dynamically add a contiguous memory
region to the enclave with the new stack preceding the new TCS. With the
new TCS initialized with encl_dyn_entry as entry point the absolute address
of the stack is computed correctly on entry.

Signed-off-by: Reinette Chatre <>
tools/testing/selftests/sgx/test_encl_bootstrap.S | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/tools/testing/selftests/sgx/test_encl_bootstrap.S b/tools/testing/selftests/sgx/test_encl_bootstrap.S
index 82fb0dfcbd23..03ae0f57e29d 100644
--- a/tools/testing/selftests/sgx/test_encl_bootstrap.S
+++ b/tools/testing/selftests/sgx/test_encl_bootstrap.S
@@ -45,6 +45,12 @@ encl_entry:
# TCS #2. By adding the value of encl_stack to it, we get
# the absolute address for the stack.
lea (encl_stack)(%rbx), %rax
+ jmp encl_entry_core
+ # Entry point for dynamically created TCS page expected to follow
+ # its stack directly.
+ lea -1(%rbx), %rax
xchg %rsp, %rax
push %rax

 \ /
  Last update: 2021-12-01 20:25    [W:0.390 / U:7.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site