From 560706d5d2589ef510f5436d69ab510a351b8cf7 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 18 Jan 2019 11:58:06 +0100 Subject: gcc-plugins: arm_ssp_per_task_plugin: sign extend the SP mask 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 Signed-off-by: Ard Biesheuvel Signed-off-by: Kees Cook --- scripts/gcc-plugins/arm_ssp_per_task_plugin.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'scripts/gcc-plugins/arm_ssp_per_task_plugin.c') diff --git a/scripts/gcc-plugins/arm_ssp_per_task_plugin.c b/scripts/gcc-plugins/arm_ssp_per_task_plugin.c index de70b8470971..a65fbefb8501 100644 --- a/scripts/gcc-plugins/arm_ssp_per_task_plugin.c +++ b/scripts/gcc-plugins/arm_ssp_per_task_plugin.c @@ -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, -- cgit v1.2.3-59-g8ed1b