From 9914215d8992b66bf7ccedf0befb31581955fae5 Mon Sep 17 00:00:00 2001 From: Zakharov Vlad Date: Thu, 18 Aug 2016 08:52:33 +0300 Subject: [PATCH] uclibc: ARC: Support syscall ABI v4 When used with GCC 6 ABIv4 is used. Missing this patch leads to numerous runtime errors. The patch has already been accepted in uclibc-ng: http://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/commit/?id=3e40f9669279f005f7154892539166f5081fbcb2 So the patch should be removed after update to a new version of uclibc-ng. Signed-off-by: Vlad Zakharov Signed-off-by: Thomas Petazzoni --- .../0003-ARC-Support-syscall-ABI-v4.patch | 54 +++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 package/uclibc/0003-ARC-Support-syscall-ABI-v4.patch diff --git a/package/uclibc/0003-ARC-Support-syscall-ABI-v4.patch b/package/uclibc/0003-ARC-Support-syscall-ABI-v4.patch new file mode 100644 index 0000000000..058adcac99 --- /dev/null +++ b/package/uclibc/0003-ARC-Support-syscall-ABI-v4.patch @@ -0,0 +1,54 @@ +From 3e40f9669279f005f7154892539166f5081fbcb2 Mon Sep 17 00:00:00 2001 +From: Vineet Gupta +Date: Tue, 16 Aug 2016 15:04:27 -0700 +Subject: [PATCH] ARC: Support syscall ABI v4 + +The syscall ABI includes the gcc functional calling ABI since a syscall +implies userland caller and kernel callee. + +The current gcc ABI (v3) for ARCv2 ISA required 64-bit data be passed in +even-odd register pairs, (potentially punching reg holes when passing such +values as args). This was partly driven by the fact that the double-word +LDD/STD instructions in ARCv2 expect the register alignment and thus gcc +forcing this avoids extra MOV at the cost of a few unused register (which we +have plenty anyways). + +This however was rejected as part of upstreaming gcc port to HS. So the new +ABI v4 doesn't enforce the even-odd reg restriction. + +Do note that for ARCompact ISA builds v3 and v4 are practically the same in +terms of gcc code generation. + +This change is dormant for now (gcc 4.8.x based tools) and will only kick +in with switch to gcc 6.x based tools. + +Signed-off-by: Vineet Gupta +Signed-off-by: Vlad Zakharov +--- + libc/sysdeps/linux/arc/bits/uClibc_arch_features.h | 10 ++++++++-- + 1 file changed, 8 insertions(+), 2 deletions(-) + +diff --git a/libc/sysdeps/linux/arc/bits/uClibc_arch_features.h b/libc/sysdeps/linux/arc/bits/uClibc_arch_features.h +index 5160724..94e089d 100755 +--- a/libc/sysdeps/linux/arc/bits/uClibc_arch_features.h ++++ b/libc/sysdeps/linux/arc/bits/uClibc_arch_features.h +@@ -41,8 +41,14 @@ + /* The default ';' is a comment on ARC. */ + #define __UCLIBC_ASM_LINE_SEP__ ` + +-/* does your target align 64bit values in register pairs ? (32bit arches only) */ +-#if defined(__A7__) ++/* does your target align 64bit values in register pairs ? (32bit arches only) ++ * - ARC700 never had any constraint on reg pairs (even if ABI v3) ++ * - Inital HS ABI (v3: non upstream gcc) had 64-bit data aligned in even-odd ++ * reg pairs (thus allowed reg holes when passing such args to calls) ++ * - Upstream gcc (6.x) HS ABI doesn't have that restriction ++ */ ++ ++#if defined(__A7__) || (__GNUC__ > 4) + #undef __UCLIBC_SYSCALL_ALIGN_64BIT__ + #else + #define __UCLIBC_SYSCALL_ALIGN_64BIT__ +-- +2.7.4 + -- 2.30.2