From: Victor Do Nascimento <victor.donascimento@arm.com>
To: <newlib@sourceware.org>
Cc: <richard.earnshaw@arm.com>,
Victor Do Nascimento <victor.donascimento@arm.com>
Subject: [PATCH v2 3/8] newlib: libc: strlen M-profile PACBTI-enablement
Date: Wed, 3 Aug 2022 16:35:19 +0100 [thread overview]
Message-ID: <20220803153524.20631-4-victor.donascimento@arm.com> (raw)
In-Reply-To: <20220803153524.20631-1-victor.donascimento@arm.com>
Add function prologue/epilogue to conditionally add BTI landing pads
and/or PAC code generation & authentication instructions depending on
compilation flags.
This patch enables PACBTI for all relevant variants of strlen:
* Newlib for armv8.1-m.main+pacbti
* Newlib for armv8.1-m.main+pacbti+mve
* Newlib-nano
---
newlib/libc/machine/arm/strlen-armv7.S | 53 ++++++++++++++++++++--
newlib/libc/machine/arm/strlen-thumb2-Os.S | 13 ++++--
2 files changed, 60 insertions(+), 6 deletions(-)
diff --git a/newlib/libc/machine/arm/strlen-armv7.S b/newlib/libc/machine/arm/strlen-armv7.S
index f3dda0d60..0492800f9 100644
--- a/newlib/libc/machine/arm/strlen-armv7.S
+++ b/newlib/libc/machine/arm/strlen-armv7.S
@@ -59,6 +59,7 @@
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
#include "acle-compat.h"
+#include "pacbti.h"
.macro def_fn f p2align=0
.text
@@ -78,7 +79,11 @@
/* This code requires Thumb. */
#if __ARM_ARCH_PROFILE == 'M'
+#if __ARM_ARCH >= 8
+ /* keep config inherited from -march=. */
+#else
.arch armv7e-m
+#endif /* if __ARM_ARCH >= 8 */
#else
.arch armv6t2
#endif
@@ -100,8 +105,35 @@
#define tmp2 r5
def_fn strlen p2align=6
+ .fnstart
+ .cfi_startproc
+ /* common pacbti_prologue macro from pacbti.h not used.
+ handwritten prologue saves one push instruction. */
+#if __HAVE_PAC_LEAF
+#if __ARM_FEATURE_BTI_DEFAULT
+ pacbti ip, lr, sp
+#else
+ pac ip, lr, sp
+#endif /* __ARM_FEATURE_BTI_DEFAULT */
+ .cfi_register 143, 12
+ push {r4, r5, ip}
+ .save {r4, r5, ra_auth_code}
+ .cfi_def_cfa_offset 12
+ .cfi_offset 143, -4
+ .cfi_offset 5, -8
+ .cfi_offset 4, -12
+
+#else
+#if __ARM_FEATURE_BTI_DEFAULT
+ bti
+#endif /* __ARM_FEATURE_BTI_DEFAULT */
+ push {r4, r5}
+ .save {r4, r5}
+ .cfi_def_cfa_offset 8
+ .cfi_offset 5, -4
+ .cfi_offset 4, -8
+#endif /* __HAVE_PAC_LEAF */
pld [srcin, #0]
- strd r4, r5, [sp, #-8]!
bic src, srcin, #7
mvn const_m1, #0
ands tmp1, srcin, #7 /* (8 - bytes) to alignment. */
@@ -159,9 +191,22 @@ def_fn strlen p2align=6
rev data1a, data1a
#endif
clz data1a, data1a
- ldrd r4, r5, [sp], #8
add result, result, data1a, lsr #3 /* Bits -> Bytes. */
- bx lr
+#if __HAVE_PAC_LEAF
+ pop {r4, r5, ip}
+ .cfi_restore 4
+ .cfi_restore 5
+ .cfi_restore 143
+ .cfi_def_cfa_offset 0
+ aut ip, lr, sp
+#else
+ ldrd r4, r5, [sp], #8
+ .cfi_restore 4
+ .cfi_restore 5
+ .cfi_def_cfa_offset 0
+#endif /* __HAVE_PAC_LEAF */
+ bx lr
+
.Lmisaligned8:
ldrd data1a, data1b, [src]
@@ -177,4 +222,6 @@ def_fn strlen p2align=6
movne data1a, const_m1
mov const_0, #0
b .Lstart_realigned
+ .cfi_endproc
+ .fnend
.size strlen, . - strlen
diff --git a/newlib/libc/machine/arm/strlen-thumb2-Os.S b/newlib/libc/machine/arm/strlen-thumb2-Os.S
index 961f41a0a..571068dac 100644
--- a/newlib/libc/machine/arm/strlen-thumb2-Os.S
+++ b/newlib/libc/machine/arm/strlen-thumb2-Os.S
@@ -25,6 +25,7 @@
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
#include "acle-compat.h"
+#include "pacbti.h"
.macro def_fn f p2align=0
.text
@@ -33,8 +34,9 @@
.type \f, %function
\f:
.endm
-
-#if __ARM_ARCH_ISA_THUMB >= 2 && __ARM_ARCH >= 7
+#if __ARM_ARCH_PROFILE == 'M' && __ARM_ARCH >= 8
+ /* keep config inherited from -march=. */
+#elif __ARM_ARCH_ISA_THUMB >= 2 && __ARM_ARCH >= 7
.arch armv7
#else
.arch armv6t2
@@ -44,11 +46,16 @@
.syntax unified
def_fn strlen p2align=1
+ .fnstart
+ .cfi_startproc
+ pacbti_prologue
mov r3, r0
1: ldrb.w r2, [r3], #1
cmp r2, #0
bne 1b
subs r0, r3, r0
subs r0, #1
- bx lr
+ pacbti_epilogue
+ .cfi_endproc
+ .fnend
.size strlen, . - strlen
--
2.36.1
next prev parent reply other threads:[~2022-08-03 15:35 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-03 15:35 [PATCH v2 0/8] Implement assembly cortex-M PACBTI functionality Victor Do Nascimento
2022-08-03 15:35 ` [PATCH v2 1/8] newlib: libc: define M-profile PACBTI-enablement macros Victor Do Nascimento
2022-08-04 15:19 ` Richard Earnshaw
2022-08-05 9:21 ` Victor L. Do Nascimento
2022-08-16 16:11 ` Victor L. Do Nascimento
2022-08-18 16:28 ` Victor L. Do Nascimento
2022-08-03 15:35 ` [PATCH v2 2/8] newlib: libc: strcmp M-profile PACBTI-enablement Victor Do Nascimento
2022-08-04 15:48 ` Richard Earnshaw
2022-08-05 10:51 ` Victor L. Do Nascimento
2022-08-05 14:34 ` Richard Earnshaw
2022-08-05 14:58 ` Victor L. Do Nascimento
2022-08-05 15:15 ` Richard Earnshaw
2022-08-03 15:35 ` Victor Do Nascimento [this message]
2022-08-03 15:35 ` [PATCH v2 4/8] newlib: libc: memchr " Victor Do Nascimento
2022-08-03 15:35 ` [PATCH v2 5/8] newlib: libc: memcpy " Victor Do Nascimento
2022-08-03 15:35 ` [PATCH v2 6/8] newlib: libc: setjmp/longjmp " Victor Do Nascimento
2022-08-03 15:35 ` [PATCH v2 7/8] newlib: libc: aeabi_memmove " Victor Do Nascimento
2022-08-03 15:35 ` [PATCH v2 8/8] newlib: libc: aeabi_memset " Victor Do Nascimento
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