commit a23860a812b3f671a869811e8a8dbeeced507618
author Jerome Forissier <jerome@forissier.org> Tue Nov 05 14:41:35 2019 +0000
committer Jérôme Forissier <jerome@forissier.org> Thu Nov 07 11:36:01 2019 +0000
tree 1ba4e385f16a09a98779306cb983a318c2b27b88
parent d135e217f7605fff80bf411084fdd25e2268755c

arm32: compile assembler code with -marm by default

When CFG_FTRACE_SUPPORT=y, thumb mode should not be used in TA code,
because the ftrace code assumes arm instructions. Therefore we have to
pass the -marm switch to the compiler and assembler. This is correctly
done for the C compiler but not for the assembler. The same applies to
assembler files in the TEE core when CFG_SYSCALL_FTRACE=y.

More generally and for simplicity, we will assume that all _a32.S files
should be compiled in arm mode and therefore add -marm to
arm32-platform-aflags. Any exception can be handled via file-specific
flags in sub.mk.

Fixes a crash in the setjmp()/longjmp() test of xtest 1006 when Linaro's
GCC 6.2 is used to build the user space libutils.a (more precisely:
lib/libutils/isoc/arch/arm/setjmp_a32.S):

 E/TC:? 0 User TA prefetch-abort at address 0x0 (translation fault)
 E/TC:? 0  fsr 0x00000005  ttbr0 0x0e19206a  ttbr1 0x0e18806a  cidr 0x2
 E/TC:? 0  cpu #1          cpsr 0x60000110
 E/TC:? 0  r0 0x00000000      r4 0x00115780    r8 0x00000000   r12 0x00115658
 E/TC:? 0  r1 0x00000001      r5 0x0011fb8c    r9 0x00000000    sp 0x001156a0
 E/TC:? 0  r2 0x00000000      r6 0x60000110   r10 0x00000000    lr 0x00000000
 E/TC:? 0  r3 0x00000000      r7 0x00000000   r11 0x001156bc    pc 0x00000000
 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 0x00a000 flags r-xs (ldelf)
 E/LD:  region  2: va 0x0010e000 pa 0x0e30c000 size 0x001000 flags rw-s (ldelf)
 E/LD:  region  3: va 0x0010f000 pa 0x0e30d000 size 0x003000 flags rw-s (ldelf)
 E/LD:  region  4: va 0x00112000 pa 0x0e310000 size 0x001000 flags r--s
 E/LD:  region  5: va 0x00113000 pa 0x0e444000 size 0x003000 flags rw-s (stack)
 E/LD:  region  6: va 0x0011b000 pa 0x00001000 size 0x024000 flags r-xs [0]
 E/LD:  region  7: va 0x0013f000 pa 0x00025000 size 0x10f000 flags rw-s [0]
 E/LD:  region  8: va 0x00266000 pa 0x00000000 size 0x003000 flags r-xs [1]
 E/LD:  region  9: va 0x00269000 pa 0x00002000 size 0x002000 flags rw-s [1]
 E/LD:  region 10: va 0x00300000 pa 0x40a67570 size 0x001000 flags rw-- (param)
 E/LD:   [0] 5b9e0e40-2636-11e1-ad9e-0002a5d5c51b @ 0x0011b000
 E/LD:   [1] ffd2bded-ab7d-4988-95ee-e4962fff7154 @ 0x00266000
 E/LD:  Call stack:
 E/LD:   0x00000000

Note: the crash is due to the fact that the compiler was configured for
-mthumb by default, whereas Arm's GCC 8.3 for instance defaults to
-marm. The compiler switches can be checked with:

 $ echo 'void f() {};' | \
     arm-linux-gnueabihf-gcc -frecord-gcc-switches -xc -c - -o test
 $ readelf -p .GCC.command.line test

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