gcc-plugins: arm_ssp_per_task_plugin: sign extend the SP mask (560706d5) · Commits · 戴 / test

The ARM per-task stack protector GCC plugin hits an assert in the compiler in some case, due to the fact the the SP mask expression is not sign-extended as it should be. So fix that. Suggested-by:

Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org> Signed-off-by:

Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by:

Kees Cook <keescook@chromium.org>

scripts/gcc-plugins/arm_ssp_per_task_plugin.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -13,7 +13,7 @@ static unsigned int arm_pertask_ssp_rtl_execute(void)
		for (insn = get_insns(); insn; insn = NEXT_INSN(insn)) {
		const char *sym;
		rtx body;
		rtx masked_sp;
		rtx mask, masked_sp;

		/*
		* Find a SET insn involving a SYMBOL_REF to __stack_chk_guard
		@@ -33,12 +33,13 @@ static unsigned int arm_pertask_ssp_rtl_execute(void)
		* produces the address of the copy of the stack canary value
		* stored in struct thread_info
		*/
		mask = GEN_INT(sext_hwi(sp_mask, GET_MODE_PRECISION(Pmode)));
		masked_sp = gen_reg_rtx(Pmode);

		emit_insn_before(gen_rtx_SET(masked_sp,
		gen_rtx_AND(Pmode,
		stack_pointer_rtx,
		GEN_INT(sp_mask))),
		mask)),
		insn);

		SET_SRC(body) = gen_rtx_PLUS(Pmode, masked_sp,

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