gprof: fix TEE core crash by allocating sample buffer dynamically

The gprof sample buffer is in user space memory but is also accessed by
the TEE core. Currently, space is reserved by the TA linker

gprof: fix TEE core crash by allocating sample buffer dynamically

The gprof sample buffer is in user space memory but is also accessed by
the TEE core. Currently, space is reserved by the TA linker script. The
address and size of the buffer is passed to the TEE core via a call to
the gprof PTA. After this call, the TEE core accesses the buffer
periodically, such as when the TA is interrupted by a timer interrupt.

Commit ef305e54eac8 ("libutee: allocate temp secmem for invoke")
modified the way that private TA memory is mapped in TA to TA
invocations, so that memory is mapped only for the duration of the
call. After this point, the memory is unmapped so the gprof sample
buffer becomes inaccessible, resulting in a crash:

E/TC:0 0 Core data-abort at address 0x121356 (translation fault)
E/TC:0 0 fsr 0x00000007 ttbr0 0x0e19206a ttbr1 0x0e18806a cidr 0x2
E/TC:0 0 cpu #0 cpsr 0x800001f2
E/TC:0 0 r0 0x00000000 r4 0x00000000 r8 0x00000000 r12 0x0017bb4b
E/TC:0 0 r1 0x000021ab r5 0x00000000 r9 0x00000000 sp 0x0e1928f0
E/TC:0 0 r2 0x0011d000 r6 0x00000000 r10 0x00000000 lr 0x0e112763
E/TC:0 0 r3 0x00121356 r7 0x0e1928f0 r11 0x00000000 pc 0x0e12958e
E/TC:0 0 Core data-abort at address 0x121356 .debug_info+1184598 (translation fault)
E/TC:0 0 Call stack:
E/TC:0 0 0x0e12958e tee_ta_gprof_sample_pc at optee_os/core/kernel/tee_ta_manager.c:897

The solution is to allocate and map the sample buffer explicitly in
user space when profiling is initialized, and at the same time get rid
of the reserved area in the TA linker script. The TEE core also needs
to check that the sample buffer is valid before writing to it,
otherwise a malicious TA could crash the core by unmapping that memory.

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

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Add SPDX license identifiers

Adds one SPDX-License-Identifier line [1] to each source files that
contains license text.

Generated by [2]:
spdxify.py --add-spdx optee_os/

The scancode tool [3] wa

Add SPDX license identifiers

Adds one SPDX-License-Identifier line [1] to each source files that
contains license text.

Generated by [2]:
spdxify.py --add-spdx optee_os/

The scancode tool [3] was used to double check the license matching
code in the Python script. All the licenses detected by scancode are
either detected by spdxify.py, or have no SPDX identifier, or are false
matches.

Link: [1] https://spdx.org/licenses/
Link: [2] https://github.com/jforissier/misc/blob/f7b56c8/spdxify.py
Link: [3] https://github.com/nexB/scancode-toolkit
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Acked-by: Joakim Bech <joakim.bech@linaro.org>

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Add support for user TA profiling with gprof (-pg)

Adds the infrastructure to collect profiling information from Trusted
Applications running in user mode and instrumented with -pg.
Enable with: CFG

Add support for user TA profiling with gprof (-pg)

Adds the infrastructure to collect profiling information from Trusted
Applications running in user mode and instrumented with -pg.
Enable with: CFG_TA_GPROF_SUPPORT=y.

Profiling support in itself adds no significant performance overhead.
Instrumented applications however may run 1.3x - 2x slower, and have a
larger .bss section (+1.36 times .text size for 32-bit TAs, +1.77 times
.text size for 64-bit ones).

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Tested-by: Jerome Forissier <jerome.forissier@linaro.org> (D02 64-bit)
Tested-by: Jerome Forissier <jerome.forissier@linaro.org> (QEMU 32-bit)
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>

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