Commit 94de486e authored by Mark Brown's avatar Mark Brown Committed by Catalin Marinas
Browse files

kselftest/arm64: Correct misleading comments on fp-stress irritators 



The comments in the handlers for the irritator signal in the test threads
for fp-stress suggest that the irritator will corrupt the register state
observed by the main thread but this is not the case, instead the FPSIMD
and SVE irritators (which are the only ones that are implemented) modify
the current register state which is expected to be overwritten on return
from the handler by the saved register state. Update the comment to reflect
what the handler is actually doing.

Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241107-arm64-fp-stress-irritator-v2-1-c4b9622e36ee@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 161e9925

tools/testing/selftests/arm64/fp/fpsimd-test.S

+1 −2
Original line number Diff line number Diff line
@@ -134,8 +134,7 @@ function check_vreg 
	b	memcmp

endfunction



// Any SVE register modified here can cause corruption in the main

// thread -- but *only* the registers modified here.

// Modify live register state, the signal return will undo our changes

function irritator_handler

	// Increment the irritation signal count (x23):

	ldr	x0, [x2, #ucontext_regs + 8 * 23]

tools/testing/selftests/arm64/fp/sve-test.S

+1 −2
Original line number Diff line number Diff line
@@ -291,8 +291,7 @@ function check_ffr 
#endif

endfunction



// Any SVE register modified here can cause corruption in the main

// thread -- but *only* the registers modified here.

// Modify live register state, the signal return will undo our changes

function irritator_handler

	// Increment the irritation signal count (x23):

	ldr	x0, [x2, #ucontext_regs + 8 * 23]