On 2023-05-23 22:12:38+0200, Willy Tarreau wrote:
Hi Thomas, Zhangjin,
I merged and pushed this series on top of the previous series, it's in branch 20230523-nolibc-rv32+stkp3.
However, Thomas, I found an issue with this last patch that I partially reverted in a last patch I pushed as well so that we can discuss it:
On Sun, May 21, 2023 at 11:36:35AM +0200, Thomas Weißschuh wrote:
-CFLAGS_STACKPROTECTOR = -DNOLIBC_STACKPROTECTOR \
$(call cc-option,-mstack-protector-guard=global) \$(call cc-option,-fstack-protector-all)-CFLAGS_STKP_i386 = $(CFLAGS_STACKPROTECTOR) -CFLAGS_STKP_x86_64 = $(CFLAGS_STACKPROTECTOR) -CFLAGS_STKP_x86 = $(CFLAGS_STACKPROTECTOR) -CFLAGS_STKP_arm64 = $(CFLAGS_STACKPROTECTOR) -CFLAGS_STKP_arm = $(CFLAGS_STACKPROTECTOR) -CFLAGS_STKP_mips = $(CFLAGS_STACKPROTECTOR) -CFLAGS_STKP_riscv = $(CFLAGS_STACKPROTECTOR) -CFLAGS_STKP_loongarch = $(CFLAGS_STACKPROTECTOR) +CFLAGS_STACKPROTECTOR = $(call cc-option,-mstack-protector-guard=global -fstack-protector-all) CFLAGS_s390 = -m64 CFLAGS ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c89 \ $(call cc-option,-fno-stack-protector) \
$(call cc-option,-mstack-protector-guard=global $(call cc-option,-fstack-protector-all)) \By doing so, we reintroduce the forced stack-protector mechanism that cannot be disabled anymore. The ability to disable it was the main point of the options above. In fact checking __SSP__* was a solution to save the user from having to set -DNOLIBC_STACKPROTECTOR to match their compiler's flags, but here in the nolibc-test we still want to be able to forcefully disable stkp for a run (at least to unbreak gcc-9, and possibly to confirm that non-stkp builds still continue to work when your local toolchain has it by default).
Wouldn't this work?
make CFLAGS_x86=-fno-stack-protector nolibc-test
Or we do
CFLAGS_STACKPROTECTOR ?= $(call cc-option,-mstack-protector-guard=global $(call cc-option,-fstack-protector-all)) CFLAGS ?= ... $(CFLAGS_STACKPROTECTOR)
And then it is always:
make CFLAGS_STACKPROTECTOR= nolibc-test
An alternative would also be to use a GCC 9 compatible mechanism:
#if __has_attribute(no_stack_protector) #define __no_stack_protector __attribute__((no_stack_protector)) #else #define __no_stack_protector __attribute__((__optimize__("-fno-stack-protector"))) #endif
Or we combine CFLAGS_STACKPROTECTOR and __no_stack_protector.
So I reverted that part and only dropped -DNOLIBC_STACKPROTECTOR. This way I could run the test on all archs with gcc-9 by forcing CFLAGS_STACKPROTECTOR= and verified it was still possible to disable it for a specific arch only by setting CFLAGS_STKP_$ARCH.
If you're fine with this we can squash this one into your cleanup patch.
To be honest I was happy to get rid of all these architecture specific variables.
Zhangjin I think this branch should work well enough for you to serve as a base for your upcoming series. We'll clean it up later once we all agree on the stat() replacement for syscall() and on the various remaining points including your time32 alternatives.
Thanks to you both, Willy
PS: we're still carrying a long CC list of individuals who are likely not that much interested in our discussion, I propose that we trim it on next exchanges and only keep us 3 and the lists, in order to remove some of their e-mail pollution.
I trimmed the list a bit.
Thomas