From 7339fb11aea8387d1ceb260323a2c87faa48fdcd Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 23 Apr 2024 08:50:38 +0100 Subject: ARM: 9390/2: lib: Annotate loop delay instructions for CFI When we annotate the loop delay code with SYM_TYPED_FUNC_START() a function prototype signature will be emitted into the object file above each site called from C, and the delay loop code is using "fallthroughs" from the different assembly callbacks. This will not work as the execution flow will run into the prototype signatures. Rewrite the code to use explicit branches to the other code segments and annotate the code using SYM_TYPED_FUNC_START(). Tested on the ARM Versatile which uses the calibrated loop delay. Tested-by: Kees Cook Reviewed-by: Sami Tolvanen Signed-off-by: Linus Walleij Signed-off-by: Russell King (Oracle) --- arch/arm/lib/delay-loop.S | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'arch/arm/lib/delay-loop.S') diff --git a/arch/arm/lib/delay-loop.S b/arch/arm/lib/delay-loop.S index 3ac05177d097..33b08ca1c242 100644 --- a/arch/arm/lib/delay-loop.S +++ b/arch/arm/lib/delay-loop.S @@ -5,6 +5,7 @@ * Copyright (C) 1995, 1996 Russell King */ #include +#include #include #include @@ -24,21 +25,26 @@ * HZ <= 1000 */ -ENTRY(__loop_udelay) +SYM_TYPED_FUNC_START(__loop_udelay) ldr r2, .LC1 mul r0, r2, r0 @ r0 = delay_us * UDELAY_MULT -ENTRY(__loop_const_udelay) @ 0 <= r0 <= 0xfffffaf0 + b __loop_const_udelay +SYM_FUNC_END(__loop_udelay) + +SYM_TYPED_FUNC_START(__loop_const_udelay) @ 0 <= r0 <= 0xfffffaf0 ldr r2, .LC0 ldr r2, [r2] umull r1, r0, r2, r0 @ r0-r1 = r0 * loops_per_jiffy adds r1, r1, #0xffffffff @ rounding up ... adcs r0, r0, r0 @ and right shift by 31 reteq lr + b __loop_delay +SYM_FUNC_END(__loop_const_udelay) .align 3 @ Delay routine -ENTRY(__loop_delay) +SYM_TYPED_FUNC_START(__loop_delay) subs r0, r0, #1 #if 0 retls lr @@ -58,6 +64,4 @@ ENTRY(__loop_delay) #endif bhi __loop_delay ret lr -ENDPROC(__loop_udelay) -ENDPROC(__loop_const_udelay) -ENDPROC(__loop_delay) +SYM_FUNC_END(__loop_delay) -- cgit v1.2.3