From 344717a14cd7272f88346022a77742323346299e Mon Sep 17 00:00:00 2001 From: Ravi Bangoria Date: Fri, 29 Jan 2021 12:47:45 +0530 Subject: powerpc/sstep: Fix array out of bound warning Compiling kernel with -Warray-bounds throws below warning: In function 'emulate_vsx_store': warning: array subscript is above array bounds [-Warray-bounds] buf.d[2] = byterev_8(reg->d[1]); ~~~~~^~~ buf.d[3] = byterev_8(reg->d[0]); ~~~~~^~~ Fix it by using temporary array variable 'union vsx_reg buf32[]' in that code block. Also, with element_size = 32, 'union vsx_reg *reg' is an array of size 2. So, use 'reg' as an array instead of pointer in the same code block. Fixes: af99da74333b ("powerpc/sstep: Support VSX vector paired storage access instructions") Suggested-by: Naveen N. Rao Signed-off-by: Ravi Bangoria Tested-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210129071745.111466-1-ravi.bangoria@linux.ibm.com --- arch/powerpc/lib/sstep.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index bf7a7d62ae8b..ede093e96234 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -818,13 +818,15 @@ void emulate_vsx_store(struct instruction_op *op, const union vsx_reg *reg, break; if (rev) { /* reverse 32 bytes */ - buf.d[0] = byterev_8(reg->d[3]); - buf.d[1] = byterev_8(reg->d[2]); - buf.d[2] = byterev_8(reg->d[1]); - buf.d[3] = byterev_8(reg->d[0]); - reg = &buf; + union vsx_reg buf32[2]; + buf32[0].d[0] = byterev_8(reg[1].d[1]); + buf32[0].d[1] = byterev_8(reg[1].d[0]); + buf32[1].d[0] = byterev_8(reg[0].d[1]); + buf32[1].d[1] = byterev_8(reg[0].d[0]); + memcpy(mem, buf32, size); + } else { + memcpy(mem, reg, size); } - memcpy(mem, reg, size); break; case 16: /* stxv, stxvx, stxvl, stxvll */ -- cgit v1.2.3 From bce74491c3008e27dd6e8f79a83b4faa77a08f7e Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 24 Dec 2020 02:11:41 +0900 Subject: powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o vgettimeofday.o is unnecessarily rebuilt. Adding it to 'targets' is not enough to fix the issue. Kbuild is correctly rebuilding it because the command line is changed. PowerPC builds each vdso directory twice; first in vdso_prepare to generate vdso{32,64}-offsets.h, second as part of the ordinary build process to embed vdso{32,64}.so.dbg into the kernel. The problem shows up when CONFIG_PPC_WERROR=y due to the following line in arch/powerpc/Kbuild: subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror In the preparation stage, Kbuild directly visits the vdso directories, hence it does not inherit subdir-ccflags-y. In the second descend, Kbuild adds -Werror, which results in the command line flipping with/without -Werror. It implies a potential danger; if a more critical flag that would impact the resulted vdso, the offsets recorded in the headers might be different from real offsets in the embedded vdso images. Removing the unneeded second descend solves the problem. Reported-by: Michael Ellerman Signed-off-by: Masahiro Yamada Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/linuxppc-dev/87tuslxhry.fsf@mpe.ellerman.id.au/ Link: https://lore.kernel.org/r/20201223171142.707053-1-masahiroy@kernel.org --- arch/powerpc/kernel/Makefile | 4 ++-- arch/powerpc/kernel/vdso32/Makefile | 5 +---- arch/powerpc/kernel/vdso32/vdso32_wrapper.S | 14 -------------- arch/powerpc/kernel/vdso32_wrapper.S | 14 ++++++++++++++ arch/powerpc/kernel/vdso64/Makefile | 6 +----- arch/powerpc/kernel/vdso64/vdso64_wrapper.S | 14 -------------- arch/powerpc/kernel/vdso64_wrapper.S | 14 ++++++++++++++ 7 files changed, 32 insertions(+), 39 deletions(-) delete mode 100644 arch/powerpc/kernel/vdso32/vdso32_wrapper.S create mode 100644 arch/powerpc/kernel/vdso32_wrapper.S delete mode 100644 arch/powerpc/kernel/vdso64/vdso64_wrapper.S create mode 100644 arch/powerpc/kernel/vdso64_wrapper.S (limited to 'arch') diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index fe2ef598e2ea..79ee7750937d 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -51,7 +51,7 @@ obj-y += ptrace/ obj-$(CONFIG_PPC64) += setup_64.o \ paca.o nvram_64.o note.o syscall_64.o obj-$(CONFIG_COMPAT) += sys_ppc32.o signal_32.o -obj-$(CONFIG_VDSO32) += vdso32/ +obj-$(CONFIG_VDSO32) += vdso32_wrapper.o obj-$(CONFIG_PPC_WATCHDOG) += watchdog.o obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o obj-$(CONFIG_PPC_DAWR) += dawr.o @@ -60,7 +60,7 @@ obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o obj-$(CONFIG_PPC_BOOK3S_64) += mce.o mce_power.o obj-$(CONFIG_PPC_BOOK3E_64) += exceptions-64e.o idle_book3e.o obj-$(CONFIG_PPC_BARRIER_NOSPEC) += security.o -obj-$(CONFIG_PPC64) += vdso64/ +obj-$(CONFIG_PPC64) += vdso64_wrapper.o obj-$(CONFIG_ALTIVEC) += vecemu.o obj-$(CONFIG_PPC_BOOK3S_IDLE) += idle_book3s.o procfs-y := proc_powerpc.o diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile index 9cb6f524854b..7d9a6fee0e3d 100644 --- a/arch/powerpc/kernel/vdso32/Makefile +++ b/arch/powerpc/kernel/vdso32/Makefile @@ -30,7 +30,7 @@ CC32FLAGS += -m32 KBUILD_CFLAGS := $(filter-out -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc,$(KBUILD_CFLAGS)) endif -targets := $(obj-vdso32) vdso32.so.dbg +targets := $(obj-vdso32) vdso32.so.dbg vgettimeofday.o obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32)) GCOV_PROFILE := n @@ -46,9 +46,6 @@ obj-y += vdso32_wrapper.o targets += vdso32.lds CPPFLAGS_vdso32.lds += -P -C -Upowerpc -# Force dependency (incbin is bad) -$(obj)/vdso32_wrapper.o : $(obj)/vdso32.so.dbg - # link rule for the .so file, .lds has to be first $(obj)/vdso32.so.dbg: $(src)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday.o FORCE $(call if_changed,vdso32ld_and_check) diff --git a/arch/powerpc/kernel/vdso32/vdso32_wrapper.S b/arch/powerpc/kernel/vdso32/vdso32_wrapper.S deleted file mode 100644 index 3f5ef035b0a9..000000000000 --- a/arch/powerpc/kernel/vdso32/vdso32_wrapper.S +++ /dev/null @@ -1,14 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#include -#include - - __PAGE_ALIGNED_DATA - - .globl vdso32_start, vdso32_end - .balign PAGE_SIZE -vdso32_start: - .incbin "arch/powerpc/kernel/vdso32/vdso32.so.dbg" - .balign PAGE_SIZE -vdso32_end: - - .previous diff --git a/arch/powerpc/kernel/vdso32_wrapper.S b/arch/powerpc/kernel/vdso32_wrapper.S new file mode 100644 index 000000000000..3f5ef035b0a9 --- /dev/null +++ b/arch/powerpc/kernel/vdso32_wrapper.S @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include +#include + + __PAGE_ALIGNED_DATA + + .globl vdso32_start, vdso32_end + .balign PAGE_SIZE +vdso32_start: + .incbin "arch/powerpc/kernel/vdso32/vdso32.so.dbg" + .balign PAGE_SIZE +vdso32_end: + + .previous diff --git a/arch/powerpc/kernel/vdso64/Makefile b/arch/powerpc/kernel/vdso64/Makefile index bf363ff37152..a06fb9b461fc 100644 --- a/arch/powerpc/kernel/vdso64/Makefile +++ b/arch/powerpc/kernel/vdso64/Makefile @@ -17,7 +17,7 @@ endif # Build rules -targets := $(obj-vdso64) vdso64.so.dbg +targets := $(obj-vdso64) vdso64.so.dbg vgettimeofday.o obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64)) GCOV_PROFILE := n @@ -29,15 +29,11 @@ ccflags-y := -shared -fno-common -fno-builtin -nostdlib \ -Wl,-soname=linux-vdso64.so.1 -Wl,--hash-style=both asflags-y := -D__VDSO64__ -s -obj-y += vdso64_wrapper.o targets += vdso64.lds CPPFLAGS_vdso64.lds += -P -C -U$(ARCH) $(obj)/vgettimeofday.o: %.o: %.c FORCE -# Force dependency (incbin is bad) -$(obj)/vdso64_wrapper.o : $(obj)/vdso64.so.dbg - # link rule for the .so file, .lds has to be first $(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday.o FORCE $(call if_changed,vdso64ld_and_check) diff --git a/arch/powerpc/kernel/vdso64/vdso64_wrapper.S b/arch/powerpc/kernel/vdso64/vdso64_wrapper.S deleted file mode 100644 index 1d56d81fe3b3..000000000000 --- a/arch/powerpc/kernel/vdso64/vdso64_wrapper.S +++ /dev/null @@ -1,14 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#include -#include - - __PAGE_ALIGNED_DATA - - .globl vdso64_start, vdso64_end - .balign PAGE_SIZE -vdso64_start: - .incbin "arch/powerpc/kernel/vdso64/vdso64.so.dbg" - .balign PAGE_SIZE -vdso64_end: - - .previous diff --git a/arch/powerpc/kernel/vdso64_wrapper.S b/arch/powerpc/kernel/vdso64_wrapper.S new file mode 100644 index 000000000000..1d56d81fe3b3 --- /dev/null +++ b/arch/powerpc/kernel/vdso64_wrapper.S @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include +#include + + __PAGE_ALIGNED_DATA + + .globl vdso64_start, vdso64_end + .balign PAGE_SIZE +vdso64_start: + .incbin "arch/powerpc/kernel/vdso64/vdso64.so.dbg" + .balign PAGE_SIZE +vdso64_end: + + .previous -- cgit v1.2.3 From 66f0a9e058fad50e569ad752be72e52701991fd5 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 24 Dec 2020 02:11:42 +0900 Subject: powerpc/vdso64: remove meaningless vgettimeofday.o build rule VDSO64 is only built for the 64-bit kernel, hence vgettimeofday.o is built by the generic rule in scripts/Makefile.build. This line does not provide anything useful. Signed-off-by: Masahiro Yamada Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201223171142.707053-2-masahiroy@kernel.org --- arch/powerpc/kernel/vdso64/Makefile | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/kernel/vdso64/Makefile b/arch/powerpc/kernel/vdso64/Makefile index a06fb9b461fc..2813e3f98db6 100644 --- a/arch/powerpc/kernel/vdso64/Makefile +++ b/arch/powerpc/kernel/vdso64/Makefile @@ -32,8 +32,6 @@ asflags-y := -D__VDSO64__ -s targets += vdso64.lds CPPFLAGS_vdso64.lds += -P -C -U$(ARCH) -$(obj)/vgettimeofday.o: %.o: %.c FORCE - # link rule for the .so file, .lds has to be first $(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday.o FORCE $(call if_changed,vdso64ld_and_check) -- cgit v1.2.3 From 24321ac668e452a4942598533d267805f291fdc9 Mon Sep 17 00:00:00 2001 From: Raoni Fassina Firmino Date: Mon, 1 Feb 2021 17:05:05 -0300 Subject: powerpc/64/signal: Fix regression in __kernel_sigtramp_rt64() semantics Commit 0138ba5783ae ("powerpc/64/signal: Balance return predictor stack in signal trampoline") changed __kernel_sigtramp_rt64() VDSO and trampoline code, and introduced a regression in the way glibc's backtrace()[1] detects the signal-handler stack frame. Apart from the practical implications, __kernel_sigtramp_rt64() was a VDSO function with the semantics that it is a function you can call from userspace to end a signal handling. Now this semantics are no longer valid. I believe the aforementioned change affects all releases since 5.9. This patch tries to fix both the semantics and practical aspect of __kernel_sigtramp_rt64() returning it to the previous code, whilst keeping the intended behaviour of 0138ba5783ae by adding a new symbol to serve as the jump target from the kernel to the trampoline. Now the trampoline has two parts, a new entry point and the old return point. [1] https://lists.ozlabs.org/pipermail/linuxppc-dev/2021-January/223194.html Fixes: 0138ba5783ae ("powerpc/64/signal: Balance return predictor stack in signal trampoline") Cc: stable@vger.kernel.org # v5.9+ Signed-off-by: Raoni Fassina Firmino Acked-by: Nicholas Piggin [mpe: Minor tweaks to change log formatting, add stable tag] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210201200505.iz46ubcizipnkcxe@work-tp --- arch/powerpc/kernel/vdso64/sigtramp.S | 11 ++++++++++- arch/powerpc/kernel/vdso64/vdso64.lds.S | 2 +- 2 files changed, 11 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/kernel/vdso64/sigtramp.S b/arch/powerpc/kernel/vdso64/sigtramp.S index bbf68cd01088..2d4067561293 100644 --- a/arch/powerpc/kernel/vdso64/sigtramp.S +++ b/arch/powerpc/kernel/vdso64/sigtramp.S @@ -15,11 +15,20 @@ .text +/* + * __kernel_start_sigtramp_rt64 and __kernel_sigtramp_rt64 together + * are one function split in two parts. The kernel jumps to the former + * and the signal handler indirectly (by blr) returns to the latter. + * __kernel_sigtramp_rt64 needs to point to the return address so + * glibc can correctly identify the trampoline stack frame. + */ .balign 8 .balign IFETCH_ALIGN_BYTES -V_FUNCTION_BEGIN(__kernel_sigtramp_rt64) +V_FUNCTION_BEGIN(__kernel_start_sigtramp_rt64) .Lsigrt_start: bctrl /* call the handler */ +V_FUNCTION_END(__kernel_start_sigtramp_rt64) +V_FUNCTION_BEGIN(__kernel_sigtramp_rt64) addi r1, r1, __SIGNAL_FRAMESIZE li r0,__NR_rt_sigreturn sc diff --git a/arch/powerpc/kernel/vdso64/vdso64.lds.S b/arch/powerpc/kernel/vdso64/vdso64.lds.S index 6164d1a1ba11..2f3c359cacd3 100644 --- a/arch/powerpc/kernel/vdso64/vdso64.lds.S +++ b/arch/powerpc/kernel/vdso64/vdso64.lds.S @@ -131,4 +131,4 @@ VERSION /* * Make the sigreturn code visible to the kernel. */ -VDSO_sigtramp_rt64 = __kernel_sigtramp_rt64; +VDSO_sigtramp_rt64 = __kernel_start_sigtramp_rt64; -- cgit v1.2.3