diff options
| author | Linus Walleij <linus.walleij@linaro.org> | 2024-04-23 08:50:38 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2024-04-29 14:14:21 +0100 |
| commit | 7339fb11aea8387d1ceb260323a2c87faa48fdcd (patch) | |
| tree | a8c7c58084ce572998e3ac2036a405c13ef1724e | |
| parent | 393999fa96273bab8d6efb2f4724030916afd61b (diff) | |
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 <keescook@chromium.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
| -rw-r--r-- | arch/arm/lib/delay-loop.S | 16 |
1 files changed, 10 insertions, 6 deletions
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 <linux/linkage.h> +#include <linux/cfi_types.h> #include <asm/assembler.h> #include <asm/delay.h> @@ -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) |