configs/qemu_mips32r6: fix Linux kernel build with gcc 10.x

From [1]:

"GCC 10 (PR 91233) won't silently allow registers that are not architecturally
available to be present in the clobber list anymore, resulting in build failure
for mips*r6 targets in form of:
...
.../sysdep.h:146:2: error: the register ‘lo’ cannot be clobbered in ‘asm’ for the current target
  146 |  __asm__ volatile (	 \
      |  ^~~~~~~

This is because base R6 ISA doesn't define hi and lo registers w/o DSP extension.
This patch provides the alternative clobber list for r6 targets that won't include
those registers."

Since kernel 5.4 and mips support for generic vDSO [2], the kernel fail to build
for mips r6 cpus with gcc 10 for the same reason as glibc.

[1] https://sourceware.org/git/?p=glibc.git;a=commit;h=020b2a97bb15f807c0482f0faee2184ed05bcad8
[2] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=24640f233b466051ad3a5d2786d2951e43026c9d

Fixes:
https://gitlab.com/kubu93/buildroot/-/jobs/655618359
https://gitlab.com/kubu93/buildroot/-/jobs/655618360

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
This commit is contained in:
Romain Naour 2020-07-26 00:06:39 +02:00 committed by Thomas Petazzoni
parent 5b9ffa6fa9
commit 39a9a0117d
4 changed files with 300 additions and 0 deletions

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@ -0,0 +1,149 @@
From bb04c220d82598066eeadf49defaec1157d4d206 Mon Sep 17 00:00:00 2001
From: Romain Naour <romain.naour@gmail.com>
Date: Sat, 25 Jul 2020 11:46:01 +0200
Subject: [PATCH] mips: Do not include hi and lo in clobber list for R6
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
From [1]
"GCC 10 (PR 91233) won't silently allow registers that are not architecturally
available to be present in the clobber list anymore, resulting in build failure
for mips*r6 targets in form of:
...
.../sysdep.h:146:2: error: the register lo cannot be clobbered in asm for the current target
146 | __asm__ volatile ( \
| ^~~~~~~
This is because base R6 ISA doesn't define hi and lo registers w/o DSP extension.
This patch provides the alternative clobber list for r6 targets that won't include
those registers."
Since kernel 5.4 and mips support for generic vDSO [2], the kernel fail to build
for mips r6 cpus with gcc 10 for the same reason as glibc.
[1] https://sourceware.org/git/?p=glibc.git;a=commit;h=020b2a97bb15f807c0482f0faee2184ed05bcad8
[2] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=24640f233b466051ad3a5d2786d2951e43026c9d
Signed-off-by: Romain Naour <romain.naour@gmail.com>
---
arch/mips/include/asm/vdso/gettimeofday.h | 45 +++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h
index 0ae9b4cbc153..ea600e0ebfe7 100644
--- a/arch/mips/include/asm/vdso/gettimeofday.h
+++ b/arch/mips/include/asm/vdso/gettimeofday.h
@@ -36,12 +36,21 @@ static __always_inline long gettimeofday_fallback(
register long nr asm("v0") = __NR_gettimeofday;
register long error asm("a3");
+#if MIPS_ISA_REV >= 6
+ asm volatile(
+ " syscall\n"
+ : "=r" (ret), "=r" (error)
+ : "r" (tv), "r" (tz), "r" (nr)
+ : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+ "$14", "$15", "$24", "$25", "memory");
+#else
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (tv), "r" (tz), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
+#endif
return error ? -ret : ret;
}
@@ -60,12 +69,21 @@ static __always_inline long clock_gettime_fallback(
#endif
register long error asm("a3");
+#if MIPS_ISA_REV >= 6
+ asm volatile(
+ " syscall\n"
+ : "=r" (ret), "=r" (error)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+ "$14", "$15", "$24", "$25", "memory");
+#else
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
+#endif
return error ? -ret : ret;
}
@@ -84,12 +102,21 @@ static __always_inline int clock_getres_fallback(
#endif
register long error asm("a3");
+#if MIPS_ISA_REV >= 6
+ asm volatile(
+ " syscall\n"
+ : "=r" (ret), "=r" (error)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+ "$14", "$15", "$24", "$25", "memory");
+#else
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
+#endif
return error ? -ret : ret;
}
@@ -108,12 +135,21 @@ static __always_inline long clock_gettime32_fallback(
register long nr asm("v0") = __NR_clock_gettime;
register long error asm("a3");
+#if MIPS_ISA_REV >= 6
+ asm volatile(
+ " syscall\n"
+ : "=r" (ret), "=r" (error)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+ "$14", "$15", "$24", "$25", "memory");
+#else
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
+#endif
return error ? -ret : ret;
}
@@ -128,12 +164,21 @@ static __always_inline int clock_getres32_fallback(
register long nr asm("v0") = __NR_clock_getres;
register long error asm("a3");
+#if MIPS_ISA_REV >= 6
+ asm volatile(
+ " syscall\n"
+ : "=r" (ret), "=r" (error)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+ "$14", "$15", "$24", "$25", "memory");
+#else
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
+#endif
return error ? -ret : ret;
}
--
2.25.4

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@ -0,0 +1,149 @@
From bb04c220d82598066eeadf49defaec1157d4d206 Mon Sep 17 00:00:00 2001
From: Romain Naour <romain.naour@gmail.com>
Date: Sat, 25 Jul 2020 11:46:01 +0200
Subject: [PATCH] mips: Do not include hi and lo in clobber list for R6
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
From [1]
"GCC 10 (PR 91233) won't silently allow registers that are not architecturally
available to be present in the clobber list anymore, resulting in build failure
for mips*r6 targets in form of:
...
.../sysdep.h:146:2: error: the register lo cannot be clobbered in asm for the current target
146 | __asm__ volatile ( \
| ^~~~~~~
This is because base R6 ISA doesn't define hi and lo registers w/o DSP extension.
This patch provides the alternative clobber list for r6 targets that won't include
those registers."
Since kernel 5.4 and mips support for generic vDSO [2], the kernel fail to build
for mips r6 cpus with gcc 10 for the same reason as glibc.
[1] https://sourceware.org/git/?p=glibc.git;a=commit;h=020b2a97bb15f807c0482f0faee2184ed05bcad8
[2] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=24640f233b466051ad3a5d2786d2951e43026c9d
Signed-off-by: Romain Naour <romain.naour@gmail.com>
---
arch/mips/include/asm/vdso/gettimeofday.h | 45 +++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h
index 0ae9b4cbc153..ea600e0ebfe7 100644
--- a/arch/mips/include/asm/vdso/gettimeofday.h
+++ b/arch/mips/include/asm/vdso/gettimeofday.h
@@ -36,12 +36,21 @@ static __always_inline long gettimeofday_fallback(
register long nr asm("v0") = __NR_gettimeofday;
register long error asm("a3");
+#if MIPS_ISA_REV >= 6
+ asm volatile(
+ " syscall\n"
+ : "=r" (ret), "=r" (error)
+ : "r" (tv), "r" (tz), "r" (nr)
+ : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+ "$14", "$15", "$24", "$25", "memory");
+#else
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (tv), "r" (tz), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
+#endif
return error ? -ret : ret;
}
@@ -60,12 +69,21 @@ static __always_inline long clock_gettime_fallback(
#endif
register long error asm("a3");
+#if MIPS_ISA_REV >= 6
+ asm volatile(
+ " syscall\n"
+ : "=r" (ret), "=r" (error)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+ "$14", "$15", "$24", "$25", "memory");
+#else
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
+#endif
return error ? -ret : ret;
}
@@ -84,12 +102,21 @@ static __always_inline int clock_getres_fallback(
#endif
register long error asm("a3");
+#if MIPS_ISA_REV >= 6
+ asm volatile(
+ " syscall\n"
+ : "=r" (ret), "=r" (error)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+ "$14", "$15", "$24", "$25", "memory");
+#else
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
+#endif
return error ? -ret : ret;
}
@@ -108,12 +135,21 @@ static __always_inline long clock_gettime32_fallback(
register long nr asm("v0") = __NR_clock_gettime;
register long error asm("a3");
+#if MIPS_ISA_REV >= 6
+ asm volatile(
+ " syscall\n"
+ : "=r" (ret), "=r" (error)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+ "$14", "$15", "$24", "$25", "memory");
+#else
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
+#endif
return error ? -ret : ret;
}
@@ -128,12 +164,21 @@ static __always_inline int clock_getres32_fallback(
register long nr asm("v0") = __NR_clock_getres;
register long error asm("a3");
+#if MIPS_ISA_REV >= 6
+ asm volatile(
+ " syscall\n"
+ : "=r" (ret), "=r" (error)
+ : "r" (clkid), "r" (ts), "r" (nr)
+ : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+ "$14", "$15", "$24", "$25", "memory");
+#else
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
+#endif
return error ? -ret : ret;
}
--
2.25.4

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@ -23,6 +23,7 @@ BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.4.42"
BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/qemu/mips32r6-malta/linux.config"
BR2_LINUX_KERNEL_VMLINUX=y
BR2_GLOBAL_PATCH_DIR="board/qemu/mips32r6-malta/patches"
# Serial port config
BR2_TARGET_GENERIC_GETTY=y

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@ -23,6 +23,7 @@ BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.4.42"
BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/qemu/mips32r6el-malta/linux.config"
BR2_LINUX_KERNEL_VMLINUX=y
BR2_GLOBAL_PATCH_DIR="board/qemu/mips32r6el-malta/patches"
# Serial port config
BR2_TARGET_GENERIC_GETTY=y