diff options
Diffstat (limited to 'target/linux/generic/backport-5.4/310-v5.6-mips-vdso-fix-jalr-t9-crash-in-vdso-code.patch')
| -rw-r--r-- | target/linux/generic/backport-5.4/310-v5.6-mips-vdso-fix-jalr-t9-crash-in-vdso-code.patch | 54 |
1 files changed, 0 insertions, 54 deletions
diff --git a/target/linux/generic/backport-5.4/310-v5.6-mips-vdso-fix-jalr-t9-crash-in-vdso-code.patch b/target/linux/generic/backport-5.4/310-v5.6-mips-vdso-fix-jalr-t9-crash-in-vdso-code.patch deleted file mode 100644 index 51eef4b26b..0000000000 --- a/target/linux/generic/backport-5.4/310-v5.6-mips-vdso-fix-jalr-t9-crash-in-vdso-code.patch +++ /dev/null @@ -1,54 +0,0 @@ -From d3f703c4359ff06619b2322b91f69710453e6b6d Mon Sep 17 00:00:00 2001 -From: Victor Kamensky <kamensky@cisco.com> -Date: Tue, 11 Feb 2020 11:24:33 -0800 -Subject: [PATCH] mips: vdso: fix 'jalr t9' crash in vdso code - -Observed that when kernel is built with Yocto mips64-poky-linux-gcc, -and mips64-poky-linux-gnun32-gcc toolchain, resulting vdso contains -'jalr t9' instructions in its code and since in vdso case nobody -sets GOT table code crashes when instruction reached. On other hand -observed that when kernel is built mips-poky-linux-gcc toolchain, the -same 'jalr t9' instruction are replaced with PC relative function -calls using 'bal' instructions. - -The difference boils down to -mrelax-pic-calls and -mexplicit-relocs -gcc options that gets different default values depending on gcc -target triplets and corresponding binutils. -mrelax-pic-calls got -enabled by default only in mips-poky-linux-gcc case. MIPS binutils -ld relies on R_MIPS_JALR relocation to convert 'jalr t9' into 'bal' -and such relocation is generated only if -mrelax-pic-calls option -is on. - -Please note 'jalr t9' conversion to 'bal' can happen only to static -functions. These static PIC calls use mips local GOT entries that -are supposed to be filled with start of DSO value by run-time linker -(missing in VDSO case) and they do not have dynamic relocations. -Global mips GOT entries must have dynamic relocations and they should -be prevented by cmd_vdso_check Makefile rule. - -Solution call out -mrelax-pic-calls and -mexplicit-relocs options -explicitly while compiling MIPS vdso code. That would get correct -and consistent between different toolchains behaviour. - -Reported-by: Bruce Ashfield <bruce.ashfield@gmail.com> -Signed-off-by: Victor Kamensky <kamensky@cisco.com> -Signed-off-by: Paul Burton <paulburton@kernel.org> -Cc: linux-mips@vger.kernel.org -Cc: Ralf Baechle <ralf@linux-mips.org> -Cc: James Hogan <jhogan@kernel.org> -Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> -Cc: richard.purdie@linuxfoundation.org ---- - arch/mips/vdso/Makefile | 1 + - 1 file changed, 1 insertion(+) - ---- a/arch/mips/vdso/Makefile -+++ b/arch/mips/vdso/Makefile -@@ -26,6 +26,7 @@ ccflags-vdso := \ - cflags-vdso := $(ccflags-vdso) \ - $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \ - -O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ -+ -mrelax-pic-calls -mexplicit-relocs \ - -fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \ - $(call cc-option, -fno-asynchronous-unwind-tables) \ - $(call cc-option, -fno-stack-protector) |