* [PATCH v4 00/13] selftests/sgx: Fix compilation errors
@ 2023-08-25 13:32 Jo Van Bulck
2023-08-25 13:32 ` [PATCH v4 01/13] selftests/sgx: Fix uninitialized pointer dereference in error path Jo Van Bulck
` (12 more replies)
0 siblings, 13 replies; 25+ messages in thread
From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw)
To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck
Hi,
This is the fourth iteration of a patch series to ensure that all SGX selftests
succeed when compiling with optimizations (as tested with -O{0,1,2,3,s} for
both gcc 11.3.0 and clang 14.0.0). The aim of the patches is to avoid reliance
on undefined, compiler-specific behavior that can make the test results
fragile.
This series appends 4 new commits compared to the previous series (do let me
know if appending commits to this series is not the preferred way to handle
these?):
1. Another fix for possibly uninitialized pointer dereferences in
encl_get_entry. Note that this was only brought up as a compiler warning
when compiling the loader itself (i.e., not only the enclave) with
optimizations. Also not that the uninitialized pointers shouldn't show up
for "well-formed" enclave ELF files that properly contain a symbol table
section, but I considered it is nevertheless good practice to harden the
code against this (unlikely) case.
2. Split off the ".dyn*" and ".gnu.hash" discarding in a separate commit, as
suggested by Kay [1].
3. Split off the removal of the redundant push/pop pair in a separate commit,
as suggested by Kai [2].
4. Remove all (incomplete) CPU register cleansing assembly code on enclave
exit, reflecting earlier discussions that highlight that the test enclave
should *not* be confused with exemplary, security-hardened enclave code, and
in line with Dave's suggestion to make the test enclave more *obviously*
insecure [3].
If useful, I can also include an elementary wrapper shell script to compile and
run the tests for different compilers (gcc/clang) and optimization levels.
Reference output below:
.. Testing gcc -O0 [OK]
.. Testing gcc -O1 [OK]
.. Testing gcc -O2 [OK]
.. Testing gcc -O3 [OK]
.. Testing gcc -Os [OK]
.. Testing gcc -Ofast [OK]
.. Testing gcc -Og [OK]
.. Testing clang -O0 [OK]
.. Testing clang -O1 [OK]
.. Testing clang -O2 [OK]
.. Testing clang -O3 [OK]
.. Testing clang -Os [OK]
.. Testing clang -Ofast [OK]
.. Testing clang -Og [OK]
Changelog
---------
v4
- Remove redundant -nostartfiles compiler flag (Jarkko)
- Split dynamic symbol table removal in separate commit (Kai)
- Split redundant push/pop elimination in separate commit (Kai)
- Remove (incomplete) register cleansing on enclave exit
- Fix possibly uninitialized pointer dereferences in load.c
v3
- Refactor encl_op_array declaration and indexing (Jarkko)
- Annotate encl_buffer with "used" attribute (Kai)
- Split encl_buffer size and placement commits (Kai)
v2
- Add additional check for NULL pointer (Kai)
- Refine to produce proper static-pie executable
- Fix linker script assertions
- Specify memory clobber for inline asm instead of volatile (Kai)
- Clarify why encl_buffer non-static (Jarkko, Kai)
- Clarify -ffreestanding (Jarkko)
References
----------
[1] https://lore.kernel.org/all/90ad8638bc1c26505e33b3f436fdbc22c8d74ba9.camel@intel.com/
[2] https://lore.kernel.org/all/71ad6389da7db8541dada0276db33f98e2a4fdcf.camel@intel.com/
[3] https://lore.kernel.org/all/da0cfb1e-e347-f7f2-ac72-aec0ee0d867d@intel.com/
Best,
Jo
Jo Van Bulck (13):
selftests/sgx: Fix uninitialized pointer dereference in error path
selftests/sgx: Produce static-pie executable for test enclave
selftests/sgx: Handle relocations in test enclave
selftests/sgx: Fix linker script asserts
selftests/sgx: Include memory clobber for inline asm in test enclave
selftests/sgx: Ensure test enclave buffer is entirely preserved
selftests/sgx: Ensure expected location of test enclave buffer
selftests/sgx: Separate linker options
selftests/sgx: Specify freestanding environment for enclave
compilation
selftests/sgx: Fix uninitialized pointer dereferences
selftests/sgx: Discard unsupported ELF sections
selftests/sgx: Remove redundant enclave base address save/restore
selftests/sgx: Remove incomplete ABI sanitization code in test enclave
tools/testing/selftests/sgx/Makefile | 14 ++--
tools/testing/selftests/sgx/defines.h | 2 +
tools/testing/selftests/sgx/load.c | 9 ++-
tools/testing/selftests/sgx/sigstruct.c | 5 +-
tools/testing/selftests/sgx/test_encl.c | 65 ++++++++++++-------
tools/testing/selftests/sgx/test_encl.lds | 10 +--
.../selftests/sgx/test_encl_bootstrap.S | 28 +++-----
7 files changed, 76 insertions(+), 57 deletions(-)
--
2.25.1
^ permalink raw reply [flat|nested] 25+ messages in thread* [PATCH v4 01/13] selftests/sgx: Fix uninitialized pointer dereference in error path 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 02/13] selftests/sgx: Produce static-pie executable for test enclave Jo Van Bulck ` (11 subsequent siblings) 12 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck Ensure ctx is zero-initialized, such that the encl_measure function will not call EVP_MD_CTX_destroy with an uninitialized ctx pointer in case of an early error during key generation. Fixes: 2adcba79e69d ("selftests/x86: Add a selftest for SGX") Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Acked-by: Kai Huang <kai.huang@intel.com> --- tools/testing/selftests/sgx/sigstruct.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/sgx/sigstruct.c b/tools/testing/selftests/sgx/sigstruct.c index a07896a46364..d73b29becf5b 100644 --- a/tools/testing/selftests/sgx/sigstruct.c +++ b/tools/testing/selftests/sgx/sigstruct.c @@ -318,9 +318,9 @@ bool encl_measure(struct encl *encl) struct sgx_sigstruct *sigstruct = &encl->sigstruct; struct sgx_sigstruct_payload payload; uint8_t digest[SHA256_DIGEST_LENGTH]; + EVP_MD_CTX *ctx = NULL; unsigned int siglen; RSA *key = NULL; - EVP_MD_CTX *ctx; int i; memset(sigstruct, 0, sizeof(*sigstruct)); @@ -384,7 +384,8 @@ bool encl_measure(struct encl *encl) return true; err: - EVP_MD_CTX_destroy(ctx); + if (ctx) + EVP_MD_CTX_destroy(ctx); RSA_free(key); return false; } -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH v4 02/13] selftests/sgx: Produce static-pie executable for test enclave 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 01/13] selftests/sgx: Fix uninitialized pointer dereference in error path Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-29 10:55 ` Huang, Kai 2023-08-25 13:32 ` [PATCH v4 03/13] selftests/sgx: Handle relocations in " Jo Van Bulck ` (10 subsequent siblings) 12 siblings, 1 reply; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck The current combination of -static and -fPIC creates a static executable with position-dependent addresses for global variables. Use -static-pie and -fPIE to create a proper static position independent executable that can be loaded at any address without a dynamic linker. Link: https://lore.kernel.org/all/f9c24d89-ed72-7d9e-c650-050d722c6b04@cs.kuleuven.be/ Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> --- tools/testing/selftests/sgx/Makefile | 2 +- tools/testing/selftests/sgx/test_encl.lds | 1 + tools/testing/selftests/sgx/test_encl_bootstrap.S | 9 ++++++--- 3 files changed, 8 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/sgx/Makefile b/tools/testing/selftests/sgx/Makefile index 50aab6b57da3..1d6315a2e5f5 100644 --- a/tools/testing/selftests/sgx/Makefile +++ b/tools/testing/selftests/sgx/Makefile @@ -13,7 +13,7 @@ endif INCLUDES := -I$(top_srcdir)/tools/include HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC -z noexecstack -ENCL_CFLAGS := -Wall -Werror -static -nostdlib -nostartfiles -fPIC \ +ENCL_CFLAGS := -Wall -Werror -static-pie -nostdlib -nostartfiles -fPIE \ -fno-stack-protector -mrdrnd $(INCLUDES) TEST_CUSTOM_PROGS := $(OUTPUT)/test_sgx diff --git a/tools/testing/selftests/sgx/test_encl.lds b/tools/testing/selftests/sgx/test_encl.lds index a1ec64f7d91f..62d37160f59b 100644 --- a/tools/testing/selftests/sgx/test_encl.lds +++ b/tools/testing/selftests/sgx/test_encl.lds @@ -10,6 +10,7 @@ PHDRS SECTIONS { . = 0; + __encl_base = .; .tcs : { *(.tcs*) } : tcs diff --git a/tools/testing/selftests/sgx/test_encl_bootstrap.S b/tools/testing/selftests/sgx/test_encl_bootstrap.S index 03ae0f57e29d..4e55d91566c4 100644 --- a/tools/testing/selftests/sgx/test_encl_bootstrap.S +++ b/tools/testing/selftests/sgx/test_encl_bootstrap.S @@ -42,9 +42,12 @@ encl_entry: # RBX contains the base address for TCS, which is the first address # inside the enclave for TCS #1 and one page into the enclave for - # TCS #2. By adding the value of encl_stack to it, we get - # the absolute address for the stack. - lea (encl_stack)(%rbx), %rax + # TCS #2. First make it relative by substracting __encl_base and + # then add the address of encl_stack to get the address for the stack. + lea __encl_base(%rip), %rax + sub %rax, %rbx + lea encl_stack(%rip), %rax + add %rbx, %rax jmp encl_entry_core encl_dyn_entry: # Entry point for dynamically created TCS page expected to follow -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* Re: [PATCH v4 02/13] selftests/sgx: Produce static-pie executable for test enclave 2023-08-25 13:32 ` [PATCH v4 02/13] selftests/sgx: Produce static-pie executable for test enclave Jo Van Bulck @ 2023-08-29 10:55 ` Huang, Kai 2023-08-31 8:49 ` Jo Van Bulck 0 siblings, 1 reply; 25+ messages in thread From: Huang, Kai @ 2023-08-29 10:55 UTC (permalink / raw) To: linux-sgx, jarkko, linux-kernel, Van Bulck, Jo; +Cc: dave.hansen On Fri, 2023-08-25 at 15:32 +0200, Jo Van Bulck wrote: > The current combination of -static and -fPIC creates a static executable > with position-dependent addresses for global variables. Use -static-pie > and -fPIE to create a proper static position independent executable that > can be loaded at any address without a dynamic linker. > > Link: https://lore.kernel.org/all/f9c24d89-ed72-7d9e-c650-050d722c6b04@cs.kuleuven.be/ > Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> > --- > tools/testing/selftests/sgx/Makefile | 2 +- > tools/testing/selftests/sgx/test_encl.lds | 1 + > tools/testing/selftests/sgx/test_encl_bootstrap.S | 9 ++++++--- > 3 files changed, 8 insertions(+), 4 deletions(-) > > diff --git a/tools/testing/selftests/sgx/Makefile b/tools/testing/selftests/sgx/Makefile > index 50aab6b57da3..1d6315a2e5f5 100644 > --- a/tools/testing/selftests/sgx/Makefile > +++ b/tools/testing/selftests/sgx/Makefile > @@ -13,7 +13,7 @@ endif > > INCLUDES := -I$(top_srcdir)/tools/include > HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC -z noexecstack > -ENCL_CFLAGS := -Wall -Werror -static -nostdlib -nostartfiles -fPIC \ > +ENCL_CFLAGS := -Wall -Werror -static-pie -nostdlib -nostartfiles -fPIE \ > -fno-stack-protector -mrdrnd $(INCLUDES) > > TEST_CUSTOM_PROGS := $(OUTPUT)/test_sgx > diff --git a/tools/testing/selftests/sgx/test_encl.lds b/tools/testing/selftests/sgx/test_encl.lds > index a1ec64f7d91f..62d37160f59b 100644 > --- a/tools/testing/selftests/sgx/test_encl.lds > +++ b/tools/testing/selftests/sgx/test_encl.lds > @@ -10,6 +10,7 @@ PHDRS > SECTIONS > { > . = 0; > + __encl_base = .; > .tcs : { > *(.tcs*) > } : tcs > diff --git a/tools/testing/selftests/sgx/test_encl_bootstrap.S b/tools/testing/selftests/sgx/test_encl_bootstrap.S > index 03ae0f57e29d..4e55d91566c4 100644 > --- a/tools/testing/selftests/sgx/test_encl_bootstrap.S > +++ b/tools/testing/selftests/sgx/test_encl_bootstrap.S > @@ -42,9 +42,12 @@ > encl_entry: > # RBX contains the base address for TCS, which is the first address > # inside the enclave for TCS #1 and one page into the enclave for > - # TCS #2. By adding the value of encl_stack to it, we get > - # the absolute address for the stack. > - lea (encl_stack)(%rbx), %rax > + # TCS #2. First make it relative by substracting __encl_base and > + # then add the address of encl_stack to get the address for the stack. > + lea __encl_base(%rip), %rax > + sub %rax, %rbx > + lea encl_stack(%rip), %rax > + add %rbx, %rax Could you please add the linker error (as you mentioned in the v3) to the changelog to justify this code change? And sigh.. I still don't quite understand why linker complains lea (encl_stack)(%rbx), %rax because .... > jmp encl_entry_core > encl_dyn_entry: > # Entry point for dynamically created TCS page expected to follow we have a lea -1(%rbx), %rax right here. Can't the compiler/linker just treat it as an immediate just like -1? :-( Anyway, I like this code change: Acked-by: Kai Huang <kai.huang@intel.com> ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH v4 02/13] selftests/sgx: Produce static-pie executable for test enclave 2023-08-29 10:55 ` Huang, Kai @ 2023-08-31 8:49 ` Jo Van Bulck 0 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-31 8:49 UTC (permalink / raw) To: Huang, Kai, linux-sgx, jarkko, linux-kernel; +Cc: dave.hansen On 29.08.23 12:55, Huang, Kai wrote:> Could you please add the linker error (as you mentioned in the v3) to the > changelog to justify this code change? Makes sense, done. > And sigh.. I still don't quite understand why linker complains > > lea (encl_stack)(%rbx), %rax > > because .... > >> jmp encl_entry_core >> encl_dyn_entry: >> # Entry point for dynamically created TCS page expected to follow > > we have a > > lea -1(%rbx), %rax > > right here. > > Can't the compiler/linker just treat it as an immediate just like -1? :-( I think the linker complains because with -static-pie -fPIE afaik all local symbols need to have RIP-relative addressing "encl_stack(%rip)". Best, Jo ^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v4 03/13] selftests/sgx: Handle relocations in test enclave 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 01/13] selftests/sgx: Fix uninitialized pointer dereference in error path Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 02/13] selftests/sgx: Produce static-pie executable for test enclave Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-28 13:15 ` Huang, Kai 2023-08-25 13:32 ` [PATCH v4 04/13] selftests/sgx: Fix linker script asserts Jo Van Bulck ` (9 subsequent siblings) 12 siblings, 1 reply; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck Static-pie binaries normally include a startup routine to perform any ELF relocations from .rela.dyn. Since the enclave loading process is different and glibc is not included, do the necessary relocation for encl_op_array entries manually at runtime relative to the enclave base to ensure correct function pointers. Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> --- tools/testing/selftests/sgx/test_encl.c | 48 +++++++++++++++++-------- 1 file changed, 33 insertions(+), 15 deletions(-) diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c index c0d6397295e3..706c1f7260ff 100644 --- a/tools/testing/selftests/sgx/test_encl.c +++ b/tools/testing/selftests/sgx/test_encl.c @@ -119,21 +119,39 @@ static void do_encl_op_nop(void *_op) } +/* + * Symbol placed at the start of the enclave image by the linker script. + * Declare this extern symbol with visibility "hidden" to ensure the + * compiler does not access it through the GOT. + */ +extern const uint8_t __attribute__((visibility("hidden"))) __encl_base; + +typedef void (*encl_op_t)(void *); +static const encl_op_t encl_op_array[ENCL_OP_MAX] = { + do_encl_op_put_to_buf, + do_encl_op_get_from_buf, + do_encl_op_put_to_addr, + do_encl_op_get_from_addr, + do_encl_op_nop, + do_encl_eaccept, + do_encl_emodpe, + do_encl_init_tcs_page, +}; + void encl_body(void *rdi, void *rsi) { - const void (*encl_op_array[ENCL_OP_MAX])(void *) = { - do_encl_op_put_to_buf, - do_encl_op_get_from_buf, - do_encl_op_put_to_addr, - do_encl_op_get_from_addr, - do_encl_op_nop, - do_encl_eaccept, - do_encl_emodpe, - do_encl_init_tcs_page, - }; - - struct encl_op_header *op = (struct encl_op_header *)rdi; - - if (op->type < ENCL_OP_MAX) - (*encl_op_array[op->type])(op); + struct encl_op_header *header = (struct encl_op_header *)rdi; + encl_op_t op; + + if (header->type >= ENCL_OP_MAX) + return; + + /* + * The enclave base address needs to be added, as this call site + * *cannot be* made rip-relative by the compiler, or fixed up by + * any other possible means. + */ + op = ((uint64_t)&__encl_base) + encl_op_array[header->type]; + + (*op)(header); } -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* Re: [PATCH v4 03/13] selftests/sgx: Handle relocations in test enclave 2023-08-25 13:32 ` [PATCH v4 03/13] selftests/sgx: Handle relocations in " Jo Van Bulck @ 2023-08-28 13:15 ` Huang, Kai 2023-08-31 12:48 ` Jo Van Bulck 0 siblings, 1 reply; 25+ messages in thread From: Huang, Kai @ 2023-08-28 13:15 UTC (permalink / raw) To: linux-sgx, jarkko, linux-kernel, Van Bulck, Jo; +Cc: dave.hansen On Fri, 2023-08-25 at 15:32 +0200, Jo Van Bulck wrote: > Static-pie binaries normally include a startup routine to perform any ELF > relocations from .rela.dyn. Since the enclave loading process is different > and glibc is not included, do the necessary relocation for encl_op_array > entries manually at runtime relative to the enclave base to ensure correct > function pointers. Sorry for late reply. I am wondering is this the right justification for _this_ particular patch? Even above paragraph is true, the existing code w/o this patch can work because the generated asm code uses "lea (-xxx)(%rip), %<reg>" to get the right address and store it to the array on the stack. It stops to work because you want to use -Os, in which case the generated asm code instead initializes the array by copying an array (which has function addresses starting from 0) generated by the compiler/linker. So to me the true justification should be "using -Os breaks the code". Or do you think "the compiler generating code to initialize the array on the stack using RIP-relative addressing to get the function address" is completely a lucky thing? Anyway, it will be very helpful to include the assembly code generated both w/ and w/o using -Os here to the changelog to demonstrate the problem and we need this patch to fixup. Without those information, it's basically very hard for people to understand why this is needed. This will save maintainer's time, and make git blamer's life easy in the future. > > Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> > --- > tools/testing/selftests/sgx/test_encl.c | 48 +++++++++++++++++-------- > 1 file changed, 33 insertions(+), 15 deletions(-) > > diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c > index c0d6397295e3..706c1f7260ff 100644 > --- a/tools/testing/selftests/sgx/test_encl.c > +++ b/tools/testing/selftests/sgx/test_encl.c > @@ -119,21 +119,39 @@ static void do_encl_op_nop(void *_op) > > } > > +/* > + * Symbol placed at the start of the enclave image by the linker script. > + * Declare this extern symbol with visibility "hidden" to ensure the > + * compiler does not access it through the GOT. > + */ > +extern const uint8_t __attribute__((visibility("hidden"))) __encl_base; > + > +typedef void (*encl_op_t)(void *); > +static const encl_op_t encl_op_array[ENCL_OP_MAX] = { > + do_encl_op_put_to_buf, > + do_encl_op_get_from_buf, > + do_encl_op_put_to_addr, > + do_encl_op_get_from_addr, > + do_encl_op_nop, > + do_encl_eaccept, > + do_encl_emodpe, > + do_encl_init_tcs_page, > +}; > + > void encl_body(void *rdi, void *rsi) > { > - const void (*encl_op_array[ENCL_OP_MAX])(void *) = { > - do_encl_op_put_to_buf, > - do_encl_op_get_from_buf, > - do_encl_op_put_to_addr, > - do_encl_op_get_from_addr, > - do_encl_op_nop, > - do_encl_eaccept, > - do_encl_emodpe, > - do_encl_init_tcs_page, > - }; > - > - struct encl_op_header *op = (struct encl_op_header *)rdi; > - > - if (op->type < ENCL_OP_MAX) > - (*encl_op_array[op->type])(op); > + struct encl_op_header *header = (struct encl_op_header *)rdi; > + encl_op_t op; > + > + if (header->type >= ENCL_OP_MAX) > + return; > + > + /* > + * The enclave base address needs to be added, as this call site > + * *cannot be* made rip-relative by the compiler, or fixed up by > + * any other possible means. > + */ Is it better to explicitly call out the compiler generates RIP-relative addressing code to get the address associated with '__encl_base' symbol, so we can get the actual enclave base during runtime? Maybe it's obvious, but I am not sure :-) > + op = ((uint64_t)&__encl_base) + encl_op_array[header->type]; > + > + (*op)(header); > } ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH v4 03/13] selftests/sgx: Handle relocations in test enclave 2023-08-28 13:15 ` Huang, Kai @ 2023-08-31 12:48 ` Jo Van Bulck 0 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-31 12:48 UTC (permalink / raw) To: Huang, Kai, linux-sgx, jarkko, linux-kernel; +Cc: dave.hansen On 28.08.23 15:15, Huang, Kai wrote: > I am wondering is this the right justification for _this_ particular patch? > > Even above paragraph is true, the existing code w/o this patch can work because > the generated asm code uses "lea (-xxx)(%rip), %<reg>" to get the right address > and store it to the array on the stack. Yes, I agree the current code *happens* to work with this explicit array initialization. > It stops to work because you want to use -Os, in which case the generated asm > code instead initializes the array by copying an array (which has function > addresses starting from 0) generated by the compiler/linker. I'd say the compiler is free to perform this sensible optimization, as long as it marks any relocations in .rela.dyn. Thus, the *real* reason why it stops to work is that the enclave does not include a startup routine to perform any ELF relocations from .rela.dyn (as included in glibc). The minimal fix, done in this patch, is to not include a full .rela.dyn relocation routine with all the overheads of parsing, but simply manually relocate the only place where this may be needed, ie the function pointer table. Ultimately, I could imagine a further enhancement may also be to parse .rela.dyn at build time and make sure no other relocations are there (outside the false positives for the TCS as discussed earlier). > So to me the true justification should be "using -Os breaks the code". I'd say compiler optimizations should not break correct code. In other words, the main objective of this patch series is to avoid reliance on undefined, compiler-specific behavior that can make the test results unpredictable and fragile as compiler versions or options may change in the future. > Or do > you think "the compiler generating code to initialize the array on the stack > using RIP-relative addressing to get the function address" is completely a lucky > thing? To some extent, yes. While I only saw this with -Os for gcc, I found that clang never initializes the array on the stack and this may also change for gcc at any point I'd expect. For reference, I'm including the full encl_body assembly for both gcc and clang for -O{1,2,3,s,g} at the bottom of this email. > Anyway, it will be very helpful to include the assembly code generated both w/ > and w/o using -Os here to the changelog to demonstrate the problem and we need > this patch to fixup. > > Without those information, it's basically very hard for people to understand why > this is needed. This will save maintainer's time, and make git blamer's life > easy in the future. Makes sense, will do this for the next revision. >> + /* >> + * The enclave base address needs to be added, as this call site >> + * *cannot be* made rip-relative by the compiler, or fixed up by >> + * any other possible means. >> + */ > > Is it better to explicitly call out the compiler generates RIP-relative > addressing code to get the address associated with '__encl_base' symbol, so we > can get the actual enclave base during runtime? > > Maybe it's obvious, but I am not sure :-) > >> + op = ((uint64_t)&__encl_base) + encl_op_array[header->type]; >> + >> + (*op)(header); >> } I'm including a comment on this a few lines higher, where __encl_base is declared. Best, Jo ------ clang.-O0.log.elf 0000000000002000 <encl_body>: 2000: 55 push %rbp 2001: 48 89 e5 mov %rsp,%rbp 2004: 48 83 ec 60 sub $0x60,%rsp 2008: 48 8d 05 f1 1f 00 00 lea 0x1ff1(%rip),%rax # 4000 <encl_entry_core+0x1b77> 200f: 48 89 7d f8 mov %rdi,-0x8(%rbp) 2013: 48 89 75 f0 mov %rsi,-0x10(%rbp) 2017: 48 8d 4d b0 lea -0x50(%rbp),%rcx 201b: 48 89 cf mov %rcx,%rdi 201e: 48 89 c6 mov %rax,%rsi 2021: ba 40 00 00 00 mov $0x40,%edx 2026: e8 95 03 00 00 call 23c0 <memcpy> 202b: 48 8b 45 f8 mov -0x8(%rbp),%rax 202f: 48 89 45 a8 mov %rax,-0x58(%rbp) 2033: 48 8b 45 a8 mov -0x58(%rbp),%rax 2037: 48 83 38 08 cmpq $0x8,(%rax) 203b: 0f 83 15 00 00 00 jae 2056 <encl_body+0x56> 2041: 48 8b 45 a8 mov -0x58(%rbp),%rax 2045: 48 8b 00 mov (%rax),%rax 2048: 48 8b 44 c5 b0 mov -0x50(%rbp,%rax,8),%rax 204d: 48 8b 4d a8 mov -0x58(%rbp),%rcx 2051: 48 89 cf mov %rcx,%rdi 2054: ff d0 call *%rax 2056: 48 83 c4 60 add $0x60,%rsp 205a: 5d pop %rbp 205b: c3 ret ------ clang.-O1.log.elf 0000000000002000 <encl_body>: 2000: 50 push %rax 2001: 48 8b 07 mov (%rdi),%rax 2004: 48 83 f8 07 cmp $0x7,%rax 2008: 77 0a ja 2014 <encl_body+0x14> 200a: 48 8d 0d ef 1f 00 00 lea 0x1fef(%rip),%rcx # 4000 <encl_entry_core+0x1d86> 2011: ff 14 c1 call *(%rcx,%rax,8) 2014: 58 pop %rax 2015: c3 ret ------ clang.-O2.log.elf 0000000000002000 <encl_body>: 2000: 48 8b 07 mov (%rdi),%rax 2003: 48 83 f8 07 cmp $0x7,%rax 2007: 77 0a ja 2013 <encl_body+0x13> 2009: 48 8d 0d f0 1f 00 00 lea 0x1ff0(%rip),%rcx # 4000 <encl_entry_core+0x1cfa> 2010: ff 24 c1 jmp *(%rcx,%rax,8) 2013: c3 ret ------ clang.-O3.log.elf 0000000000002000 <encl_body>: 2000: 48 8b 07 mov (%rdi),%rax 2003: 48 83 f8 07 cmp $0x7,%rax 2007: 77 0a ja 2013 <encl_body+0x13> 2009: 48 8d 0d f0 1f 00 00 lea 0x1ff0(%rip),%rcx # 4000 <encl_entry_core+0x1cfa> 2010: ff 24 c1 jmp *(%rcx,%rax,8) 2013: c3 ret ------ clang.-Ofast.log.elf 0000000000002000 <encl_body>: 2000: 48 8b 07 mov (%rdi),%rax 2003: 48 83 f8 07 cmp $0x7,%rax 2007: 77 0a ja 2013 <encl_body+0x13> 2009: 48 8d 0d f0 1f 00 00 lea 0x1ff0(%rip),%rcx # 4000 <encl_entry_core+0x1cfa> 2010: ff 24 c1 jmp *(%rcx,%rax,8) 2013: c3 ret ------ clang.-Og.log.elf 0000000000002000 <encl_body>: 2000: 50 push %rax 2001: 48 8b 07 mov (%rdi),%rax 2004: 48 83 f8 07 cmp $0x7,%rax 2008: 77 0a ja 2014 <encl_body+0x14> 200a: 48 8d 0d ef 1f 00 00 lea 0x1fef(%rip),%rcx # 4000 <encl_entry_core+0x1d86> 2011: ff 14 c1 call *(%rcx,%rax,8) 2014: 58 pop %rax 2015: c3 ret ------ clang.-Os.log.elf 0000000000002000 <encl_body>: 2000: 48 8b 07 mov (%rdi),%rax 2003: 48 83 f8 07 cmp $0x7,%rax 2007: 77 0a ja 2013 <encl_body+0x13> 2009: 48 8d 0d f0 1f 00 00 lea 0x1ff0(%rip),%rcx # 4000 <encl_entry_core+0x1e36> 2010: ff 24 c1 jmp *(%rcx,%rax,8) 2013: c3 ret ------ gcc.-O0.log.elf 00000000000023f4 <encl_body>: 23f4: f3 0f 1e fa endbr64 23f8: 55 push %rbp 23f9: 48 89 e5 mov %rsp,%rbp 23fc: 48 83 ec 60 sub $0x60,%rsp 2400: 48 89 7d a8 mov %rdi,-0x58(%rbp) 2404: 48 89 75 a0 mov %rsi,-0x60(%rbp) 2408: 48 8d 05 ec fe ff ff lea -0x114(%rip),%rax # 22fb <do_encl_op_put_to_buf> 240f: 48 89 45 b0 mov %rax,-0x50(%rbp) 2413: 48 8d 05 18 ff ff ff lea -0xe8(%rip),%rax # 2332 <do_encl_op_get_from_buf> 241a: 48 89 45 b8 mov %rax,-0x48(%rbp) 241e: 48 8d 05 44 ff ff ff lea -0xbc(%rip),%rax # 2369 <do_encl_op_put_to_addr> 2425: 48 89 45 c0 mov %rax,-0x40(%rbp) 2429: 48 8d 05 77 ff ff ff lea -0x89(%rip),%rax # 23a7 <do_encl_op_get_from_addr> 2430: 48 89 45 c8 mov %rax,-0x38(%rbp) 2434: 48 8d 05 aa ff ff ff lea -0x56(%rip),%rax # 23e5 <do_encl_op_nop> 243b: 48 89 45 d0 mov %rax,-0x30(%rbp) 243f: 48 8d 05 4f fc ff ff lea -0x3b1(%rip),%rax # 2095 <do_encl_eaccept> 2446: 48 89 45 d8 mov %rax,-0x28(%rbp) 244a: 48 8d 05 af fb ff ff lea -0x451(%rip),%rax # 2000 <do_encl_emodpe> 2451: 48 89 45 e0 mov %rax,-0x20(%rbp) 2455: 48 8d 05 72 fd ff ff lea -0x28e(%rip),%rax # 21ce <do_encl_init_tcs_page> 245c: 48 89 45 e8 mov %rax,-0x18(%rbp) 2460: 48 8b 45 a8 mov -0x58(%rbp),%rax 2464: 48 89 45 f8 mov %rax,-0x8(%rbp) 2468: 48 8b 45 f8 mov -0x8(%rbp),%rax 246c: 48 8b 00 mov (%rax),%rax 246f: 48 83 f8 07 cmp $0x7,%rax 2473: 77 15 ja 248a <encl_body+0x96> 2475: 48 8b 45 f8 mov -0x8(%rbp),%rax 2479: 48 8b 00 mov (%rax),%rax 247c: 48 8b 54 c5 b0 mov -0x50(%rbp,%rax,8),%rdx 2481: 48 8b 45 f8 mov -0x8(%rbp),%rax 2485: 48 89 c7 mov %rax,%rdi 2488: ff d2 call *%rdx 248a: 90 nop 248b: c9 leave 248c: c3 ret ------ gcc.-O1.log.elf 0000000000002239 <encl_body>: 2239: f3 0f 1e fa endbr64 223d: 48 83 ec 48 sub $0x48,%rsp 2241: 48 8d 05 b6 fe ff ff lea -0x14a(%rip),%rax # 20fe <do_encl_op_put_to_buf> 2248: 48 89 04 24 mov %rax,(%rsp) 224c: 48 8d 05 c5 fe ff ff lea -0x13b(%rip),%rax # 2118 <do_encl_op_get_from_buf> 2253: 48 89 44 24 08 mov %rax,0x8(%rsp) 2258: 48 8d 05 d3 fe ff ff lea -0x12d(%rip),%rax # 2132 <do_encl_op_put_to_addr> 225f: 48 89 44 24 10 mov %rax,0x10(%rsp) 2264: 48 8d 05 de fe ff ff lea -0x122(%rip),%rax # 2149 <do_encl_op_get_from_addr> 226b: 48 89 44 24 18 mov %rax,0x18(%rsp) 2270: 48 8d 05 e9 fe ff ff lea -0x117(%rip),%rax # 2160 <do_encl_op_nop> 2277: 48 89 44 24 20 mov %rax,0x20(%rsp) 227c: 48 8d 05 e9 fd ff ff lea -0x217(%rip),%rax # 206c <do_encl_eaccept> 2283: 48 89 44 24 28 mov %rax,0x28(%rsp) 2288: 48 8d 05 71 fd ff ff lea -0x28f(%rip),%rax # 2000 <do_encl_emodpe> 228f: 48 89 44 24 30 mov %rax,0x30(%rsp) 2294: 48 8d 05 ca fe ff ff lea -0x136(%rip),%rax # 2165 <do_encl_init_tcs_page> 229b: 48 89 44 24 38 mov %rax,0x38(%rsp) 22a0: 48 8b 07 mov (%rdi),%rax 22a3: 48 83 f8 07 cmp $0x7,%rax 22a7: 77 03 ja 22ac <encl_body+0x73> 22a9: ff 14 c4 call *(%rsp,%rax,8) 22ac: 48 83 c4 48 add $0x48,%rsp 22b0: c3 ret ------ gcc.-O2.log.elf 0000000000002210 <encl_body>: 2210: f3 0f 1e fa endbr64 2214: 48 8d 05 25 ff ff ff lea -0xdb(%rip),%rax # 2140 <do_encl_op_put_to_buf> 221b: 48 89 44 24 b8 mov %rax,-0x48(%rsp) 2220: 48 8d 05 49 ff ff ff lea -0xb7(%rip),%rax # 2170 <do_encl_op_get_from_buf> 2227: 48 89 44 24 c0 mov %rax,-0x40(%rsp) 222c: 48 8d 05 6d ff ff ff lea -0x93(%rip),%rax # 21a0 <do_encl_op_put_to_addr> 2233: 48 89 44 24 c8 mov %rax,-0x38(%rsp) 2238: 48 8d 05 91 ff ff ff lea -0x6f(%rip),%rax # 21d0 <do_encl_op_get_from_addr> 223f: 48 89 44 24 d0 mov %rax,-0x30(%rsp) 2244: 48 8d 05 b5 ff ff ff lea -0x4b(%rip),%rax # 2200 <do_encl_op_nop> 224b: 48 89 44 24 d8 mov %rax,-0x28(%rsp) 2250: 48 8d 05 f9 fd ff ff lea -0x207(%rip),%rax # 2050 <do_encl_eaccept> 2257: 48 89 44 24 e0 mov %rax,-0x20(%rsp) 225c: 48 8d 05 9d fd ff ff lea -0x263(%rip),%rax # 2000 <do_encl_emodpe> 2263: 48 89 44 24 e8 mov %rax,-0x18(%rsp) 2268: 48 8d 05 31 fe ff ff lea -0x1cf(%rip),%rax # 20a0 <do_encl_init_tcs_page> 226f: 48 89 44 24 f0 mov %rax,-0x10(%rsp) 2274: 48 8b 07 mov (%rdi),%rax 2277: 48 83 f8 07 cmp $0x7,%rax 227b: 77 0b ja 2288 <encl_body+0x78> 227d: ff 64 c4 b8 jmp *-0x48(%rsp,%rax,8) 2281: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 2288: c3 ret ------ gcc.-O3.log.elf 0000000000002220 <encl_body>: 2220: f3 0f 1e fa endbr64 2224: 48 8d 05 55 ff ff ff lea -0xab(%rip),%rax # 2180 <do_encl_op_get_from_buf> 222b: 48 8d 15 3e ff ff ff lea -0xc2(%rip),%rdx # 2170 <do_encl_op_put_to_buf> 2232: 66 48 0f 6e c2 movq %rdx,%xmm0 2237: 66 48 0f 6e c8 movq %rax,%xmm1 223c: 48 8d 0d 4d ff ff ff lea -0xb3(%rip),%rcx # 2190 <do_encl_op_put_to_addr> 2243: 66 0f 6c c1 punpcklqdq %xmm1,%xmm0 2247: 48 8d 05 82 ff ff ff lea -0x7e(%rip),%rax # 21d0 <do_encl_op_get_from_addr> 224e: 48 8d 35 bb ff ff ff lea -0x45(%rip),%rsi # 2210 <do_encl_op_nop> 2255: 66 48 0f 6e d0 movq %rax,%xmm2 225a: 0f 29 44 24 b8 movaps %xmm0,-0x48(%rsp) 225f: 66 48 0f 6e c1 movq %rcx,%xmm0 2264: 48 8d 05 e5 fd ff ff lea -0x21b(%rip),%rax # 2050 <do_encl_eaccept> 226b: 66 0f 6c c2 punpcklqdq %xmm2,%xmm0 226f: 66 48 0f 6e d8 movq %rax,%xmm3 2274: 48 8d 15 85 fd ff ff lea -0x27b(%rip),%rdx # 2000 <do_encl_emodpe> 227b: 0f 29 44 24 c8 movaps %xmm0,-0x38(%rsp) 2280: 66 48 0f 6e c6 movq %rsi,%xmm0 2285: 48 8d 05 14 fe ff ff lea -0x1ec(%rip),%rax # 20a0 <do_encl_init_tcs_page> 228c: 66 0f 6c c3 punpcklqdq %xmm3,%xmm0 2290: 66 48 0f 6e e0 movq %rax,%xmm4 2295: 48 8b 07 mov (%rdi),%rax 2298: 0f 29 44 24 d8 movaps %xmm0,-0x28(%rsp) 229d: 66 48 0f 6e c2 movq %rdx,%xmm0 22a2: 66 0f 6c c4 punpcklqdq %xmm4,%xmm0 22a6: 0f 29 44 24 e8 movaps %xmm0,-0x18(%rsp) 22ab: 48 83 f8 07 cmp $0x7,%rax 22af: 77 07 ja 22b8 <encl_body+0x98> 22b1: ff 64 c4 b8 jmp *-0x48(%rsp,%rax,8) 22b5: 0f 1f 00 nopl (%rax) 22b8: c3 ret ------ gcc.-Ofast.log.elf 0000000000002220 <encl_body>: 2220: f3 0f 1e fa endbr64 2224: 48 8d 05 55 ff ff ff lea -0xab(%rip),%rax # 2180 <do_encl_op_get_from_buf> 222b: 48 8d 15 3e ff ff ff lea -0xc2(%rip),%rdx # 2170 <do_encl_op_put_to_buf> 2232: 66 48 0f 6e c2 movq %rdx,%xmm0 2237: 66 48 0f 6e c8 movq %rax,%xmm1 223c: 48 8d 0d 4d ff ff ff lea -0xb3(%rip),%rcx # 2190 <do_encl_op_put_to_addr> 2243: 66 0f 6c c1 punpcklqdq %xmm1,%xmm0 2247: 48 8d 05 82 ff ff ff lea -0x7e(%rip),%rax # 21d0 <do_encl_op_get_from_addr> 224e: 48 8d 35 bb ff ff ff lea -0x45(%rip),%rsi # 2210 <do_encl_op_nop> 2255: 66 48 0f 6e d0 movq %rax,%xmm2 225a: 0f 29 44 24 b8 movaps %xmm0,-0x48(%rsp) 225f: 66 48 0f 6e c1 movq %rcx,%xmm0 2264: 48 8d 05 e5 fd ff ff lea -0x21b(%rip),%rax # 2050 <do_encl_eaccept> 226b: 66 0f 6c c2 punpcklqdq %xmm2,%xmm0 226f: 66 48 0f 6e d8 movq %rax,%xmm3 2274: 48 8d 15 85 fd ff ff lea -0x27b(%rip),%rdx # 2000 <do_encl_emodpe> 227b: 0f 29 44 24 c8 movaps %xmm0,-0x38(%rsp) 2280: 66 48 0f 6e c6 movq %rsi,%xmm0 2285: 48 8d 05 14 fe ff ff lea -0x1ec(%rip),%rax # 20a0 <do_encl_init_tcs_page> 228c: 66 0f 6c c3 punpcklqdq %xmm3,%xmm0 2290: 66 48 0f 6e e0 movq %rax,%xmm4 2295: 48 8b 07 mov (%rdi),%rax 2298: 0f 29 44 24 d8 movaps %xmm0,-0x28(%rsp) 229d: 66 48 0f 6e c2 movq %rdx,%xmm0 22a2: 66 0f 6c c4 punpcklqdq %xmm4,%xmm0 22a6: 0f 29 44 24 e8 movaps %xmm0,-0x18(%rsp) 22ab: 48 83 f8 07 cmp $0x7,%rax 22af: 77 07 ja 22b8 <encl_body+0x98> 22b1: ff 64 c4 b8 jmp *-0x48(%rsp,%rax,8) 22b5: 0f 1f 00 nopl (%rax) 22b8: c3 ret ------ gcc.-Og.log.elf 000000000000225f <encl_body>: 225f: f3 0f 1e fa endbr64 2263: 48 83 ec 48 sub $0x48,%rsp 2267: 48 8d 05 8a ff ff ff lea -0x76(%rip),%rax # 21f8 <do_encl_op_put_to_buf> 226e: 48 89 04 24 mov %rax,(%rsp) 2272: 48 8d 05 99 ff ff ff lea -0x67(%rip),%rax # 2212 <do_encl_op_get_from_buf> 2279: 48 89 44 24 08 mov %rax,0x8(%rsp) 227e: 48 8d 05 a7 ff ff ff lea -0x59(%rip),%rax # 222c <do_encl_op_put_to_addr> 2285: 48 89 44 24 10 mov %rax,0x10(%rsp) 228a: 48 8d 05 b2 ff ff ff lea -0x4e(%rip),%rax # 2243 <do_encl_op_get_from_addr> 2291: 48 89 44 24 18 mov %rax,0x18(%rsp) 2296: 48 8d 05 bd ff ff ff lea -0x43(%rip),%rax # 225a <do_encl_op_nop> 229d: 48 89 44 24 20 mov %rax,0x20(%rsp) 22a2: 48 8d 05 cc fd ff ff lea -0x234(%rip),%rax # 2075 <do_encl_eaccept> 22a9: 48 89 44 24 28 mov %rax,0x28(%rsp) 22ae: 48 8d 05 4b fd ff ff lea -0x2b5(%rip),%rax # 2000 <do_encl_emodpe> 22b5: 48 89 44 24 30 mov %rax,0x30(%rsp) 22ba: 48 8d 05 64 fe ff ff lea -0x19c(%rip),%rax # 2125 <do_encl_init_tcs_page> 22c1: 48 89 44 24 38 mov %rax,0x38(%rsp) 22c6: 48 8b 07 mov (%rdi),%rax 22c9: 48 83 f8 07 cmp $0x7,%rax 22cd: 77 03 ja 22d2 <encl_body+0x73> 22cf: ff 14 c4 call *(%rsp,%rax,8) 22d2: 48 83 c4 48 add $0x48,%rsp 22d6: c3 ret ------ gcc.-Os.log.elf 00000000000021a9 <encl_body>: 21a9: f3 0f 1e fa endbr64 21ad: 49 89 f8 mov %rdi,%r8 21b0: 48 8d 35 49 1e 00 00 lea 0x1e49(%rip),%rsi # 4000 <encl_entry_core+0x1e0f> 21b7: 48 8d 7c 24 b8 lea -0x48(%rsp),%rdi 21bc: b9 10 00 00 00 mov $0x10,%ecx 21c1: f3 a5 rep movsl %ds:(%rsi),%es:(%rdi) 21c3: 49 8b 00 mov (%r8),%rax 21c6: 48 83 f8 07 cmp $0x7,%rax 21ca: 77 0a ja 21d6 <encl_body+0x2d> 21cc: 48 8b 44 c4 b8 mov -0x48(%rsp,%rax,8),%rax 21d1: 4c 89 c7 mov %r8,%rdi 21d4: ff e0 jmp *%rax 21d6: c3 ret ^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v4 04/13] selftests/sgx: Fix linker script asserts 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck ` (2 preceding siblings ...) 2023-08-25 13:32 ` [PATCH v4 03/13] selftests/sgx: Handle relocations in " Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 05/13] selftests/sgx: Include memory clobber for inline asm in test enclave Jo Van Bulck ` (8 subsequent siblings) 12 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck DEFINED only considers symbols, not section names. Hence, replace the check for .got.plt with the _GLOBAL_OFFSET_TABLE_ symbol and remove other (non-essential) asserts. Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> --- tools/testing/selftests/sgx/test_encl.lds | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/tools/testing/selftests/sgx/test_encl.lds b/tools/testing/selftests/sgx/test_encl.lds index 62d37160f59b..6ffdfc9fb4cf 100644 --- a/tools/testing/selftests/sgx/test_encl.lds +++ b/tools/testing/selftests/sgx/test_encl.lds @@ -35,8 +35,4 @@ SECTIONS } } -ASSERT(!DEFINED(.altinstructions), "ALTERNATIVES are not supported in enclaves") -ASSERT(!DEFINED(.altinstr_replacement), "ALTERNATIVES are not supported in enclaves") -ASSERT(!DEFINED(.discard.retpoline_safe), "RETPOLINE ALTERNATIVES are not supported in enclaves") -ASSERT(!DEFINED(.discard.nospec), "RETPOLINE ALTERNATIVES are not supported in enclaves") -ASSERT(!DEFINED(.got.plt), "Libcalls are not supported in enclaves") +ASSERT(!DEFINED(_GLOBAL_OFFSET_TABLE_), "Libcalls through GOT are not supported in enclaves") -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH v4 05/13] selftests/sgx: Include memory clobber for inline asm in test enclave 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck ` (3 preceding siblings ...) 2023-08-25 13:32 ` [PATCH v4 04/13] selftests/sgx: Fix linker script asserts Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-29 11:07 ` Huang, Kai 2023-08-25 13:32 ` [PATCH v4 06/13] selftests/sgx: Ensure test enclave buffer is entirely preserved Jo Van Bulck ` (7 subsequent siblings) 12 siblings, 1 reply; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck Add the "memory" clobber to the EMODPE and EACCEPT asm blocks to tell the compiler the assembly code accesses to the secinfo struct. This ensures the compiler treats the asm block as a memory barrier and the write to secinfo will be visible to ENCLU. Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> Reviewed-by: Kai Huang <kai.huang@intel.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> --- tools/testing/selftests/sgx/test_encl.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c index 706c1f7260ff..dfe531c5f560 100644 --- a/tools/testing/selftests/sgx/test_encl.c +++ b/tools/testing/selftests/sgx/test_encl.c @@ -24,10 +24,11 @@ static void do_encl_emodpe(void *_op) secinfo.flags = op->flags; asm volatile(".byte 0x0f, 0x01, 0xd7" - : + : /* no outputs */ : "a" (EMODPE), "b" (&secinfo), - "c" (op->epc_addr)); + "c" (op->epc_addr) + : "memory" /* read from secinfo pointer */); } static void do_encl_eaccept(void *_op) @@ -42,7 +43,8 @@ static void do_encl_eaccept(void *_op) : "=a" (rax) : "a" (EACCEPT), "b" (&secinfo), - "c" (op->epc_addr)); + "c" (op->epc_addr) + : "memory" /* read from secinfo pointer */); op->ret = rax; } -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* Re: [PATCH v4 05/13] selftests/sgx: Include memory clobber for inline asm in test enclave 2023-08-25 13:32 ` [PATCH v4 05/13] selftests/sgx: Include memory clobber for inline asm in test enclave Jo Van Bulck @ 2023-08-29 11:07 ` Huang, Kai 2023-08-31 8:31 ` Jo Van Bulck 0 siblings, 1 reply; 25+ messages in thread From: Huang, Kai @ 2023-08-29 11:07 UTC (permalink / raw) To: linux-sgx, jarkko, linux-kernel, Van Bulck, Jo; +Cc: dave.hansen On Fri, 2023-08-25 at 15:32 +0200, Jo Van Bulck wrote: > Add the "memory" clobber to the EMODPE and EACCEPT asm blocks to tell the > compiler the assembly code accesses to the secinfo struct. This ensures > the compiler treats the asm block as a memory barrier and the write to > secinfo will be visible to ENCLU. > > Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> > Reviewed-by: Kai Huang <kai.huang@intel.com> > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> > --- > tools/testing/selftests/sgx/test_encl.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c > index 706c1f7260ff..dfe531c5f560 100644 > --- a/tools/testing/selftests/sgx/test_encl.c > +++ b/tools/testing/selftests/sgx/test_encl.c > @@ -24,10 +24,11 @@ static void do_encl_emodpe(void *_op) > secinfo.flags = op->flags; > > asm volatile(".byte 0x0f, 0x01, 0xd7" > - : > + : /* no outputs */ > : "a" (EMODPE), > "b" (&secinfo), > - "c" (op->epc_addr)); > + "c" (op->epc_addr) > + : "memory" /* read from secinfo pointer */); > } > > static void do_encl_eaccept(void *_op) > @@ -42,7 +43,8 @@ static void do_encl_eaccept(void *_op) > : "=a" (rax) > : "a" (EACCEPT), > "b" (&secinfo), > - "c" (op->epc_addr)); > + "c" (op->epc_addr) > + : "memory" /* read from secinfo pointer */); > > op->ret = rax; > } To me this is also a bug fix patch, thus as Jarkko said should be ahead of other non-bug fix patches. And also include the Fixes tag? ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH v4 05/13] selftests/sgx: Include memory clobber for inline asm in test enclave 2023-08-29 11:07 ` Huang, Kai @ 2023-08-31 8:31 ` Jo Van Bulck 0 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-31 8:31 UTC (permalink / raw) To: Huang, Kai, linux-sgx, jarkko, linux-kernel; +Cc: dave.hansen On 29.08.23 13:07, Huang, Kai wrote:> To me this is also a bug fix patch, thus as Jarkko said should be ahead of other > non-bug fix patches. > > And also include the Fixes tag? Thanks, moving this ahead and including the tag Fixes: 20404a808593 ("selftests/sgx: Add test for EPCM permission changes") Best, Jo ^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v4 06/13] selftests/sgx: Ensure test enclave buffer is entirely preserved 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck ` (4 preceding siblings ...) 2023-08-25 13:32 ` [PATCH v4 05/13] selftests/sgx: Include memory clobber for inline asm in test enclave Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 07/13] selftests/sgx: Ensure expected location of test enclave buffer Jo Van Bulck ` (6 subsequent siblings) 12 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck Attach the "used" attribute to instruct the compiler to preserve the static encl_buffer, even if it appears it is not entirely referenced in the enclave code, as expected by the external tests manipulating page permissions. Link: https://lore.kernel.org/all/a2732938-f3db-a0af-3d68-a18060f66e79@cs.kuleuven.be/ Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Acked-by: Kai Huang <kai.huang@intel.com> --- tools/testing/selftests/sgx/defines.h | 1 + tools/testing/selftests/sgx/test_encl.c | 9 +++++---- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h index d8587c971941..b8f482667ce1 100644 --- a/tools/testing/selftests/sgx/defines.h +++ b/tools/testing/selftests/sgx/defines.h @@ -13,6 +13,7 @@ #define __aligned(x) __attribute__((__aligned__(x))) #define __packed __attribute__((packed)) +#define __used __attribute__((used)) #include "../../../../arch/x86/include/asm/sgx.h" #include "../../../../arch/x86/include/asm/enclu.h" diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c index dfe531c5f560..81070492230f 100644 --- a/tools/testing/selftests/sgx/test_encl.c +++ b/tools/testing/selftests/sgx/test_encl.c @@ -5,11 +5,12 @@ #include "defines.h" /* - * Data buffer spanning two pages that will be placed first in .data - * segment. Even if not used internally the second page is needed by - * external test manipulating page permissions. + * Data buffer spanning two pages that will be placed first in the .data + * segment. Even if not used internally the second page is needed by external + * test manipulating page permissions, so mark encl_buffer as "used" to make + * sure it is entirely preserved by the compiler. */ -static uint8_t encl_buffer[8192] = { 1 }; +static uint8_t __used encl_buffer[8192] = { 1 }; enum sgx_enclu_function { EACCEPT = 0x5, -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH v4 07/13] selftests/sgx: Ensure expected location of test enclave buffer 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck ` (5 preceding siblings ...) 2023-08-25 13:32 ` [PATCH v4 06/13] selftests/sgx: Ensure test enclave buffer is entirely preserved Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 08/13] selftests/sgx: Separate linker options Jo Van Bulck ` (5 subsequent siblings) 12 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck The external tests manipulating page permissions expect encl_buffer to be placed at the start of the test enclave's .data section. As this is not guaranteed per the C standard, explicitly place encl_buffer in a separate section that is explicitly placed at the start of the .data segment in the linker script to avoid the compiler placing it somewhere else in .data. Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Acked-by: Kai Huang <kai.huang@intel.com> --- tools/testing/selftests/sgx/defines.h | 1 + tools/testing/selftests/sgx/test_encl.c | 8 ++++---- tools/testing/selftests/sgx/test_encl.lds | 1 + 3 files changed, 6 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h index b8f482667ce1..402f8787a71c 100644 --- a/tools/testing/selftests/sgx/defines.h +++ b/tools/testing/selftests/sgx/defines.h @@ -14,6 +14,7 @@ #define __aligned(x) __attribute__((__aligned__(x))) #define __packed __attribute__((packed)) #define __used __attribute__((used)) +#define __section(x)__attribute__((__section__(x))) #include "../../../../arch/x86/include/asm/sgx.h" #include "../../../../arch/x86/include/asm/enclu.h" diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c index 81070492230f..2ee597b9d14b 100644 --- a/tools/testing/selftests/sgx/test_encl.c +++ b/tools/testing/selftests/sgx/test_encl.c @@ -6,11 +6,11 @@ /* * Data buffer spanning two pages that will be placed first in the .data - * segment. Even if not used internally the second page is needed by external - * test manipulating page permissions, so mark encl_buffer as "used" to make - * sure it is entirely preserved by the compiler. + * segment via the linker script. Even if not used internally the second page + * is needed by external test manipulating page permissions, so mark + * encl_buffer as "used" to make sure it is entirely preserved by the compiler. */ -static uint8_t __used encl_buffer[8192] = { 1 }; +static uint8_t __used __section(".data.encl_buffer") encl_buffer[8192] = { 1 }; enum sgx_enclu_function { EACCEPT = 0x5, diff --git a/tools/testing/selftests/sgx/test_encl.lds b/tools/testing/selftests/sgx/test_encl.lds index 6ffdfc9fb4cf..333a3e78fdc9 100644 --- a/tools/testing/selftests/sgx/test_encl.lds +++ b/tools/testing/selftests/sgx/test_encl.lds @@ -24,6 +24,7 @@ SECTIONS } : text .data : { + *(.data.encl_buffer) *(.data*) } : data -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH v4 08/13] selftests/sgx: Separate linker options 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck ` (6 preceding siblings ...) 2023-08-25 13:32 ` [PATCH v4 07/13] selftests/sgx: Ensure expected location of test enclave buffer Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 09/13] selftests/sgx: Specify freestanding environment for enclave compilation Jo Van Bulck ` (4 subsequent siblings) 12 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck Fixes "'linker' input unused [-Wunused-command-line-argument]" errors when compiling with clang. Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> --- tools/testing/selftests/sgx/Makefile | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/sgx/Makefile b/tools/testing/selftests/sgx/Makefile index 1d6315a2e5f5..2de970f7237c 100644 --- a/tools/testing/selftests/sgx/Makefile +++ b/tools/testing/selftests/sgx/Makefile @@ -12,9 +12,11 @@ OBJCOPY := $(CROSS_COMPILE)objcopy endif INCLUDES := -I$(top_srcdir)/tools/include -HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC -z noexecstack +HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC +HOST_LDFLAGS := -z noexecstack -lcrypto ENCL_CFLAGS := -Wall -Werror -static-pie -nostdlib -nostartfiles -fPIE \ -fno-stack-protector -mrdrnd $(INCLUDES) +ENCL_LDFLAGS := -Wl,-T,test_encl.lds,--build-id=none TEST_CUSTOM_PROGS := $(OUTPUT)/test_sgx TEST_FILES := $(OUTPUT)/test_encl.elf @@ -28,7 +30,7 @@ $(OUTPUT)/test_sgx: $(OUTPUT)/main.o \ $(OUTPUT)/sigstruct.o \ $(OUTPUT)/call.o \ $(OUTPUT)/sign_key.o - $(CC) $(HOST_CFLAGS) -o $@ $^ -lcrypto + $(CC) $(HOST_CFLAGS) -o $@ $^ $(HOST_LDFLAGS) $(OUTPUT)/main.o: main.c $(CC) $(HOST_CFLAGS) -c $< -o $@ @@ -45,8 +47,8 @@ $(OUTPUT)/call.o: call.S $(OUTPUT)/sign_key.o: sign_key.S $(CC) $(HOST_CFLAGS) -c $< -o $@ -$(OUTPUT)/test_encl.elf: test_encl.lds test_encl.c test_encl_bootstrap.S - $(CC) $(ENCL_CFLAGS) -T $^ -o $@ -Wl,--build-id=none +$(OUTPUT)/test_encl.elf: test_encl.c test_encl_bootstrap.S + $(CC) $(ENCL_CFLAGS) $^ -o $@ $(ENCL_LDFLAGS) EXTRA_CLEAN := \ $(OUTPUT)/test_encl.elf \ -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH v4 09/13] selftests/sgx: Specify freestanding environment for enclave compilation 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck ` (7 preceding siblings ...) 2023-08-25 13:32 ` [PATCH v4 08/13] selftests/sgx: Separate linker options Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-27 18:35 ` Jarkko Sakkinen 2023-08-25 13:32 ` [PATCH v4 10/13] selftests/sgx: Fix uninitialized pointer dereferences Jo Van Bulck ` (3 subsequent siblings) 12 siblings, 1 reply; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck Use -ffreestanding to assert the enclave compilation targets a freestanding environment (i.e., without "main" or standard libraries). This fixes clang reporting "undefined reference to `memset'" after erroneously optimizing away the provided memset/memcpy implementations. Still need to instruct the linker from using standard system startup functions, but drop -nostartfiles as it is implied by -nostdlib. Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> --- tools/testing/selftests/sgx/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/sgx/Makefile b/tools/testing/selftests/sgx/Makefile index 2de970f7237c..f96667bdf9f2 100644 --- a/tools/testing/selftests/sgx/Makefile +++ b/tools/testing/selftests/sgx/Makefile @@ -14,8 +14,8 @@ endif INCLUDES := -I$(top_srcdir)/tools/include HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC HOST_LDFLAGS := -z noexecstack -lcrypto -ENCL_CFLAGS := -Wall -Werror -static-pie -nostdlib -nostartfiles -fPIE \ - -fno-stack-protector -mrdrnd $(INCLUDES) +ENCL_CFLAGS := -Wall -Werror -static-pie -nostdlib -ffreestanding -fPIE \ + -fno-stack-protector -mrdrnd $(INCLUDES) ENCL_LDFLAGS := -Wl,-T,test_encl.lds,--build-id=none TEST_CUSTOM_PROGS := $(OUTPUT)/test_sgx -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* Re: [PATCH v4 09/13] selftests/sgx: Specify freestanding environment for enclave compilation 2023-08-25 13:32 ` [PATCH v4 09/13] selftests/sgx: Specify freestanding environment for enclave compilation Jo Van Bulck @ 2023-08-27 18:35 ` Jarkko Sakkinen 0 siblings, 0 replies; 25+ messages in thread From: Jarkko Sakkinen @ 2023-08-27 18:35 UTC (permalink / raw) To: Jo Van Bulck, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen On Fri Aug 25, 2023 at 4:32 PM EEST, Jo Van Bulck wrote: > Use -ffreestanding to assert the enclave compilation targets a > freestanding environment (i.e., without "main" or standard libraries). > This fixes clang reporting "undefined reference to `memset'" after > erroneously optimizing away the provided memset/memcpy implementations. > > Still need to instruct the linker from using standard system startup > functions, but drop -nostartfiles as it is implied by -nostdlib. > > Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> > --- > tools/testing/selftests/sgx/Makefile | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/sgx/Makefile b/tools/testing/selftests/sgx/Makefile > index 2de970f7237c..f96667bdf9f2 100644 > --- a/tools/testing/selftests/sgx/Makefile > +++ b/tools/testing/selftests/sgx/Makefile > @@ -14,8 +14,8 @@ endif > INCLUDES := -I$(top_srcdir)/tools/include > HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC > HOST_LDFLAGS := -z noexecstack -lcrypto > -ENCL_CFLAGS := -Wall -Werror -static-pie -nostdlib -nostartfiles -fPIE \ > - -fno-stack-protector -mrdrnd $(INCLUDES) > +ENCL_CFLAGS := -Wall -Werror -static-pie -nostdlib -ffreestanding -fPIE \ > + -fno-stack-protector -mrdrnd $(INCLUDES) > ENCL_LDFLAGS := -Wl,-T,test_encl.lds,--build-id=none > > TEST_CUSTOM_PROGS := $(OUTPUT)/test_sgx > -- > 2.25.1 Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> BR, Jarkko ^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v4 10/13] selftests/sgx: Fix uninitialized pointer dereferences 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck ` (8 preceding siblings ...) 2023-08-25 13:32 ` [PATCH v4 09/13] selftests/sgx: Specify freestanding environment for enclave compilation Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-27 18:36 ` Jarkko Sakkinen 2023-08-25 13:32 ` [PATCH v4 11/13] selftests/sgx: Discard unsupported ELF sections Jo Van Bulck ` (2 subsequent siblings) 12 siblings, 1 reply; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck Ensure sym_tab and sym_names are zero-initialized and add an early-out condition in the unlikely (erroneous) case that the enclave ELF file would not contain a symbol table. This addresses -Werror=maybe-uninitialized compiler warnings for gcc -O2. Fixes: 33c5aac3bf32 ("selftests/sgx: Test complete changing of page type flow") Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> --- tools/testing/selftests/sgx/load.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c index 94bdeac1cf04..c9f658e44de6 100644 --- a/tools/testing/selftests/sgx/load.c +++ b/tools/testing/selftests/sgx/load.c @@ -136,11 +136,11 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg) */ uint64_t encl_get_entry(struct encl *encl, const char *symbol) { + Elf64_Sym *symtab = NULL; + char *sym_names = NULL; Elf64_Shdr *sections; - Elf64_Sym *symtab; Elf64_Ehdr *ehdr; - char *sym_names; - int num_sym; + int num_sym = 0; int i; ehdr = encl->bin; @@ -161,6 +161,9 @@ uint64_t encl_get_entry(struct encl *encl, const char *symbol) } } + if (!symtab || !sym_names) + return 0; + for (i = 0; i < num_sym; i++) { Elf64_Sym *sym = &symtab[i]; -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* Re: [PATCH v4 10/13] selftests/sgx: Fix uninitialized pointer dereferences 2023-08-25 13:32 ` [PATCH v4 10/13] selftests/sgx: Fix uninitialized pointer dereferences Jo Van Bulck @ 2023-08-27 18:36 ` Jarkko Sakkinen 2023-08-31 8:12 ` Jo Van Bulck 0 siblings, 1 reply; 25+ messages in thread From: Jarkko Sakkinen @ 2023-08-27 18:36 UTC (permalink / raw) To: Jo Van Bulck, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen On Fri Aug 25, 2023 at 4:32 PM EEST, Jo Van Bulck wrote: > Ensure sym_tab and sym_names are zero-initialized and add an early-out > condition in the unlikely (erroneous) case that the enclave ELF file would > not contain a symbol table. > > This addresses -Werror=maybe-uninitialized compiler warnings for gcc -O2. > > Fixes: 33c5aac3bf32 ("selftests/sgx: Test complete changing of page type flow") > Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> > --- > tools/testing/selftests/sgx/load.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c > index 94bdeac1cf04..c9f658e44de6 100644 > --- a/tools/testing/selftests/sgx/load.c > +++ b/tools/testing/selftests/sgx/load.c > @@ -136,11 +136,11 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg) > */ > uint64_t encl_get_entry(struct encl *encl, const char *symbol) > { > + Elf64_Sym *symtab = NULL; > + char *sym_names = NULL; > Elf64_Shdr *sections; > - Elf64_Sym *symtab; > Elf64_Ehdr *ehdr; > - char *sym_names; > - int num_sym; > + int num_sym = 0; > int i; > > ehdr = encl->bin; > @@ -161,6 +161,9 @@ uint64_t encl_get_entry(struct encl *encl, const char *symbol) > } > } > > + if (!symtab || !sym_names) > + return 0; > + > for (i = 0; i < num_sym; i++) { > Elf64_Sym *sym = &symtab[i]; > > -- > 2.25.1 Bug fixes should be always in the head of the patch set. BR, Jarkko ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH v4 10/13] selftests/sgx: Fix uninitialized pointer dereferences 2023-08-27 18:36 ` Jarkko Sakkinen @ 2023-08-31 8:12 ` Jo Van Bulck 0 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-31 8:12 UTC (permalink / raw) To: Jarkko Sakkinen, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen On 27.08.23 20:36, Jarkko Sakkinen wrote:> Bug fixes should be always in the head of the patch set. Thanks for pointing this out. I'll make sure to move this to the head in the next patch set revision. Best, Jo ^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v4 11/13] selftests/sgx: Discard unsupported ELF sections 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck ` (9 preceding siblings ...) 2023-08-25 13:32 ` [PATCH v4 10/13] selftests/sgx: Fix uninitialized pointer dereferences Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 12/13] selftests/sgx: Remove redundant enclave base address save/restore Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 13/13] selftests/sgx: Remove incomplete ABI sanitization code in test enclave Jo Van Bulck 12 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck Building the test enclave with -static-pie may produce a dynamic symbol table, but this is not supported for enclaves and any relocations need to happen manually (e.g., as for "encl_op_array"). Thus, opportunistically discard ".dyn*" and ".gnu.hash" which the enclave loader cannot handle. Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> --- tools/testing/selftests/sgx/test_encl.lds | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/sgx/test_encl.lds b/tools/testing/selftests/sgx/test_encl.lds index 333a3e78fdc9..ffe851a1cac4 100644 --- a/tools/testing/selftests/sgx/test_encl.lds +++ b/tools/testing/selftests/sgx/test_encl.lds @@ -33,6 +33,8 @@ SECTIONS *(.note*) *(.debug*) *(.eh_frame*) + *(.dyn*) + *(.gnu.hash) } } -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH v4 12/13] selftests/sgx: Remove redundant enclave base address save/restore 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck ` (10 preceding siblings ...) 2023-08-25 13:32 ` [PATCH v4 11/13] selftests/sgx: Discard unsupported ELF sections Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 2023-08-29 11:00 ` Huang, Kai 2023-08-25 13:32 ` [PATCH v4 13/13] selftests/sgx: Remove incomplete ABI sanitization code in test enclave Jo Van Bulck 12 siblings, 1 reply; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck Remove redundant push/pop pair that stores and restores the enclave base address in the test enclave, as it is never used after the pop and can anyway be easily retrieved via the __encl_base symbol. Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> --- tools/testing/selftests/sgx/test_encl_bootstrap.S | 3 --- 1 file changed, 3 deletions(-) diff --git a/tools/testing/selftests/sgx/test_encl_bootstrap.S b/tools/testing/selftests/sgx/test_encl_bootstrap.S index 4e55d91566c4..28fe5d2ac0af 100644 --- a/tools/testing/selftests/sgx/test_encl_bootstrap.S +++ b/tools/testing/selftests/sgx/test_encl_bootstrap.S @@ -58,12 +58,9 @@ encl_entry_core: push %rax push %rcx # push the address after EENTER - push %rbx # push the enclave base address call encl_body - pop %rbx # pop the enclave base address - /* Clear volatile GPRs, except RAX (EEXIT function). */ xor %rcx, %rcx xor %rdx, %rdx -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* Re: [PATCH v4 12/13] selftests/sgx: Remove redundant enclave base address save/restore 2023-08-25 13:32 ` [PATCH v4 12/13] selftests/sgx: Remove redundant enclave base address save/restore Jo Van Bulck @ 2023-08-29 11:00 ` Huang, Kai 2023-08-31 8:25 ` Jo Van Bulck 0 siblings, 1 reply; 25+ messages in thread From: Huang, Kai @ 2023-08-29 11:00 UTC (permalink / raw) To: linux-sgx, jarkko, linux-kernel, Van Bulck, Jo; +Cc: dave.hansen On Fri, 2023-08-25 at 15:32 +0200, Jo Van Bulck wrote: > Remove redundant push/pop pair that stores and restores the enclave base > address in the test enclave, as it is never used after the pop and can > anyway be easily retrieved via the __encl_base symbol. > > Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> Acked-by: Kai Huang <kai.huang@intel.com> Nit below... > --- > tools/testing/selftests/sgx/test_encl_bootstrap.S | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/tools/testing/selftests/sgx/test_encl_bootstrap.S b/tools/testing/selftests/sgx/test_encl_bootstrap.S > index 4e55d91566c4..28fe5d2ac0af 100644 > --- a/tools/testing/selftests/sgx/test_encl_bootstrap.S > +++ b/tools/testing/selftests/sgx/test_encl_bootstrap.S > @@ -58,12 +58,9 @@ encl_entry_core: > push %rax > > push %rcx # push the address after EENTER > - push %rbx # push the enclave base address > > call encl_body > > - pop %rbx # pop the enclave base address > - > /* Clear volatile GPRs, except RAX (EEXIT function). */ > xor %rcx, %rcx > xor %rdx, %rdx ... please move this patch before patch 2? Otherwise, strictly speaking patch 2 isn't complete, because after you apply patch 2 you still have this code which is obviously wrong -- %rbx is no longer enclave base address (although it never was even in the current upstream code). ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH v4 12/13] selftests/sgx: Remove redundant enclave base address save/restore 2023-08-29 11:00 ` Huang, Kai @ 2023-08-31 8:25 ` Jo Van Bulck 0 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-31 8:25 UTC (permalink / raw) To: Huang, Kai, linux-sgx, jarkko, linux-kernel; +Cc: dave.hansen On 29.08.23 13:00, Huang, Kai wrote: > ... please move this patch before patch 2? > > Otherwise, strictly speaking patch 2 isn't complete, because after you apply > patch 2 you still have this code which is obviously wrong -- %rbx is no longer > enclave base address (although it never was even in the current upstream code). Okay, moving this ahead. Best, Jo ^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v4 13/13] selftests/sgx: Remove incomplete ABI sanitization code in test enclave 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck ` (11 preceding siblings ...) 2023-08-25 13:32 ` [PATCH v4 12/13] selftests/sgx: Remove redundant enclave base address save/restore Jo Van Bulck @ 2023-08-25 13:32 ` Jo Van Bulck 12 siblings, 0 replies; 25+ messages in thread From: Jo Van Bulck @ 2023-08-25 13:32 UTC (permalink / raw) To: jarkko, kai.huang, linux-sgx, linux-kernel; +Cc: dave.hansen, Jo Van Bulck As the selftest enclave is *not* intended for production, simplify the code by not initializing CPU configuration registers as expected by the ABI on enclave entry or cleansing caller-save registers on enclave exit. Link: https://lore.kernel.org/all/da0cfb1e-e347-f7f2-ac72-aec0ee0d867d@intel.com/ Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be> --- .../testing/selftests/sgx/test_encl_bootstrap.S | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/tools/testing/selftests/sgx/test_encl_bootstrap.S b/tools/testing/selftests/sgx/test_encl_bootstrap.S index 28fe5d2ac0af..d8c4ac94e032 100644 --- a/tools/testing/selftests/sgx/test_encl_bootstrap.S +++ b/tools/testing/selftests/sgx/test_encl_bootstrap.S @@ -59,21 +59,11 @@ encl_entry_core: push %rcx # push the address after EENTER + # NOTE: as the selftest enclave is *not* intended for production, + # simplify the code by not initializing ABI registers on entry or + # cleansing caller-save registers on exit. call encl_body - /* Clear volatile GPRs, except RAX (EEXIT function). */ - xor %rcx, %rcx - xor %rdx, %rdx - xor %rdi, %rdi - xor %rsi, %rsi - xor %r8, %r8 - xor %r9, %r9 - xor %r10, %r10 - xor %r11, %r11 - - # Reset status flags. - add %rdx, %rdx # OF = SF = AF = CF = 0; ZF = PF = 1 - # Prepare EEXIT target by popping the address of the instruction after # EENTER to RBX. pop %rbx -- 2.25.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
end of thread, other threads:[~2023-08-31 12:48 UTC | newest] Thread overview: 25+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-08-25 13:32 [PATCH v4 00/13] selftests/sgx: Fix compilation errors Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 01/13] selftests/sgx: Fix uninitialized pointer dereference in error path Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 02/13] selftests/sgx: Produce static-pie executable for test enclave Jo Van Bulck 2023-08-29 10:55 ` Huang, Kai 2023-08-31 8:49 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 03/13] selftests/sgx: Handle relocations in " Jo Van Bulck 2023-08-28 13:15 ` Huang, Kai 2023-08-31 12:48 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 04/13] selftests/sgx: Fix linker script asserts Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 05/13] selftests/sgx: Include memory clobber for inline asm in test enclave Jo Van Bulck 2023-08-29 11:07 ` Huang, Kai 2023-08-31 8:31 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 06/13] selftests/sgx: Ensure test enclave buffer is entirely preserved Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 07/13] selftests/sgx: Ensure expected location of test enclave buffer Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 08/13] selftests/sgx: Separate linker options Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 09/13] selftests/sgx: Specify freestanding environment for enclave compilation Jo Van Bulck 2023-08-27 18:35 ` Jarkko Sakkinen 2023-08-25 13:32 ` [PATCH v4 10/13] selftests/sgx: Fix uninitialized pointer dereferences Jo Van Bulck 2023-08-27 18:36 ` Jarkko Sakkinen 2023-08-31 8:12 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 11/13] selftests/sgx: Discard unsupported ELF sections Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 12/13] selftests/sgx: Remove redundant enclave base address save/restore Jo Van Bulck 2023-08-29 11:00 ` Huang, Kai 2023-08-31 8:25 ` Jo Van Bulck 2023-08-25 13:32 ` [PATCH v4 13/13] selftests/sgx: Remove incomplete ABI sanitization code in test enclave Jo Van Bulck
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