diff options
| author | Jerome Forissier <jerome.forissier@linaro.org> | 2016-10-13 15:21:53 +0200 |
|---|---|---|
| committer | Jerome Forissier <jerome.forissier@linaro.org> | 2017-01-24 18:33:32 +0100 |
| commit | 883c4be3d11cacf49665f51d1d6af4c02a0a0afd (patch) | |
| tree | 05e131182cd9c1223c0be98e58d3632cf65d4f5a /ta | |
| parent | f3bb2312f41f85790c77e749f096f10be36e9506 (diff) | |
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>
Diffstat (limited to 'ta')
| -rw-r--r-- | ta/arch/arm/ta.ld.S | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/ta/arch/arm/ta.ld.S b/ta/arch/arm/ta.ld.S index 8a318401..b80abc34 100644 --- a/ta/arch/arm/ta.ld.S +++ b/ta/arch/arm/ta.ld.S @@ -1,10 +1,18 @@ #ifdef ARM32 OUTPUT_FORMAT("elf32-littlearm") OUTPUT_ARCH(arm) +#define MCOUNT_SYM __gnu_mcount_nc +/* + * This magic value corresponds to the size requested by + * libutee/arch/arm/gprof/gprof.c + */ +#define GPROF_BUF_MULT(x) ((x) * 136) / 100 #endif #ifdef ARM64 OUTPUT_FORMAT("elf64-littleaarch64") OUTPUT_ARCH(aarch64) +#define MCOUNT_SYM _mcount +#define GPROF_BUF_MULT(x) ((x) * 177) / 100 #endif PHDRS { @@ -24,6 +32,7 @@ SECTIONS { .ta_head : {*(.ta_head)} :exec .text : { + __text_start = .; *(.text .text.*) *(.stub) *(.glue_7) @@ -31,6 +40,8 @@ SECTIONS { *(.gnu.linkonce.t.*) /* Workaround for an erratum in ARM's VFP11 coprocessor */ *(.vfp11_veneer) + PROVIDE(MCOUNT_SYM = __utee_mcount); + __text_end = .; } .eh_frame : { *(.eh_frame) } :rodata .rodata : { @@ -77,7 +88,24 @@ SECTIONS { .data : { *(.data .data.* .gnu.linkonce.d.*) } :rwdata - .bss : { *(.bss .bss.* .gnu.linkonce.b.* COMMON) } + .bss : { + *(.bss .bss.* .gnu.linkonce.b.* COMMON) + + /* + * TA profiling with gprof + * Reserve some space for the profiling buffer, only if the + * TA is instrumented (i.e., some files were built with -pg). + * Note that PROVIDE() above defines a symbol only if it is + * referenced in the object files. + * This also provides a way to detect at runtime if the TA is + * instrumented or not. + */ + . = ALIGN(8); + __gprof_buf_start = .; + . += DEFINED(MCOUNT_SYM) ? + GPROF_BUF_MULT(__text_end - __text_start) : 0; + __gprof_buf_end = .; + } /DISCARD/ : { *(.interp) } } |