arm32: libutils, libutee, ta: add .note.GNU-stack section to .S files

When building for arm32 with GNU binutils 2.39, the linker outputs
warnings when linking Trusted Applications:

arm-unknown-lin

arm32: libutils, libutee, ta: add .note.GNU-stack section to .S files

When building for arm32 with GNU binutils 2.39, the linker outputs
warnings when linking Trusted Applications:

arm-unknown-linux-uclibcgnueabihf-ld.bfd: warning: utee_syscalls_a32.o: missing .note.GNU-stack section implies executable stack
arm-unknown-linux-uclibcgnueabihf-ld.bfd: NOTE: This behaviour is deprecated and will be removed in a future version of the linker

We could silence the warning by adding the '--no-warn-execstack' option
to the TA link flags, like we did in the parent commit for the TEE core
and ldelf. Indeed, ldelf always allocates a non-executable piece of
memory for the TA to use as a stack.

However it seems preferable to comply with the common ELF practices in
this case. A better fix is therefore to add the missing .note.GNU-stack
sections in the assembler files.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

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libutils: arm: add .cantunwind to __gnu_mcount_nc()

The __gnu_mcount_nc() function lacks proper annotation as registers are
pushed onto the stack. The unwind table information for this symbol is
the

libutils: arm: add .cantunwind to __gnu_mcount_nc()

The __gnu_mcount_nc() function lacks proper annotation as registers are
pushed onto the stack. The unwind table information for this symbol is
therefore incorrect and stack unwinding may fail in spectacular ways.
For example, xtest 1007 enters an infinite loop as ldelf tries to unwind
the call stack when the TA panics:

# Platform: QEMU
(buildhost)$ make CFG_FTRACE_SUPPORT=y CFLAGS_ta_arm32=-pg run
(qemu)$ xtest 1007
...
E/TC:? 0 TA panicked with code 0xbeef
E/LD: Status of TA 5b9e0e40-2636-11e1-ad9e-0002a5d5c51b
E/LD: arch: arm
E/LD: region 0: va 0x00102000 pa 0x0e300000 size 0x002000 flags rw-s (ldelf)
E/LD: region 1: va 0x00104000 pa 0x0e302000 size 0x00c000 flags r-xs (ldelf)
E/LD: region 2: va 0x00110000 pa 0x0e30e000 size 0x001000 flags rw-s (ldelf)
E/LD: region 3: va 0x00111000 pa 0x0e30f000 size 0x004000 flags rw-s (ldelf)
E/LD: region 4: va 0x00115000 pa 0x0e313000 size 0x001000 flags r--s
E/LD: region 5: va 0x00116000 pa 0x0e426000 size 0x003000 flags rw-s (stack)
E/LD: region 6: va 0x00149000 pa 0x00001000 size 0x02b000 flags r-xs [0] .ta_head .text .plt .rodata .gnu.hash .ARM.extab .ARM.exidx .dynsym .dynstr .hash
E/LD: region 7: va 0x00174000 pa 0x0002c000 size 0x0e7000 flags rw-s [0] .dynamic .tdata .tbss .got .rel.got .rel.plt .data .init_array .bss .rel.dyn
E/LD: region 8: va 0x00291000 pa 0x00000000 size 0x00b000 flags r-xs [1] .hash .gnu.hash .dynsym .dynstr .rel.dyn .rel.plt .plt .text .rodata .ARM.extab .ARM.exidx
E/LD: region 9: va 0x0029c000 pa 0x0000a000 size 0x002000 flags rw-s [1] .tdata .tbss .init_array .dynamic .got .data .bss
E/LD: [0] 5b9e0e40-2636-11e1-ad9e-0002a5d5c51b @ 0x00149000 (out-br/build/optee_test_ext-1.0/ta/os_test/out/5b9e0e40-2636-11e1-ad9e-0002a5d5c51b.elf)
E/LD: [1] ffd2bded-ab7d-4988-95ee-e4962fff7154 @ 0x00291000 (out-br/build/optee_test_ext-1.0/ta/os_test_lib/out/libos_test.so)
E/LD: Call stack:
E/LD: 0x0029481c _utee_panic at optee_os/lib/libutee/arch/arm/utee_syscalls_a32.S:51
E/LD: 0x002944fc TEE_Panic at optee_os/lib/libutee/tee_api_panic.c:24
E/LD: 0x0014c494 ta_entry_panic at out-br/build/optee_test_ext-1.0/ta/os_test/os_test.c:787
E/LD: 0x00293574 __gnu_mcount_nc at optee_os/lib/libutils/ext/arch/arm/mcount_a32.S:44
E/LD: 0x00293574 __gnu_mcount_nc at optee_os/lib/libutils/ext/arch/arm/mcount_a32.S:44
E/LD: 0x00293574 __gnu_mcount_nc at optee_os/lib/libutils/ext/arch/arm/mcount_a32.S:44
[repeats indefinitely]

The bug is triggered by commit 3513f961cda0 ("arm32: fold
UNWIND(.fnstart/.fnend) into the FUNC macros"). Prior to that commit,
the unwind entry for __gnu_mcount_nc() was "0x1 [cantunwind]", probably
because the function had no .fnstart/.fnend directive.

This commit adds a .cantunwind directive to restore the previous
behavior: unwinding stops at __gnu_mcount_nc(). Since the ftrace code
overwrites LR on the stack, it seems there is no simple way to produce
correct and comprehensive stack dumps short of introducing an unwind
helper function with a knowledge of the ftrace transformation, similar
to what ftrace_return() does.

At least with this patch the unwinding code does not fail.

Fixes: 3513f961cda0 ("arm32: fold UNWIND(.fnstart/.fnend) into the FUNC macros")
Signed-off-by: Jerome Forissier <jerome@forissier.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

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ftrace: Add support for syscall function tracer

This patch adds support for syscall tracing in TEE core. It complements
existing ftrace support for user TAs via adding trace for syscalls that
are in

ftrace: Add support for syscall function tracer

This patch adds support for syscall tracing in TEE core. It complements
existing ftrace support for user TAs via adding trace for syscalls that
are invoked by user TAs into the TEE core.

And after this patch ftrace will cover both TA and TEE core code. So lets
rename config option from CFG_TA_FTRACE_SUPPORT to CFG_FTRACE_SUPPORT.

It is optional to enable syscall trace via CFG_SYSCALL_FTRACE=y config
option in addition to CFG_FTRACE_SUPPORT=y config option.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Jerome Forissier <jerome@forissier.org>

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ftrace: core: prepare support for syscall ftrace

Enable compilation of ftrace library code for TEE core.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Jerome Forissier <jerome@fori

ftrace: core: prepare support for syscall ftrace

Enable compilation of ftrace library code for TEE core.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Jerome Forissier <jerome@forissier.org>

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ftrace: move ftrace code from libutee to libutils

Since TEE core and TA can share most of ftrace library code, so move
ftrace code from libutee to libutils library which is shared among TEE
core and

ftrace: move ftrace code from libutee to libutils

Since TEE core and TA can share most of ftrace library code, so move
ftrace code from libutee to libutils library which is shared among TEE
core and TA.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Jerome Forissier <jerome@forissier.org>

show more ...