commit b1c6ecfdd06907554518ec384ce8e99889d15193 upstream. Function syscall_trace_exit expects pointer to pt_regs. However r0 is also used to keep syscall return value. Restore pointer to pt_regs before calling syscall_trace_exit. Cc: <stable@vger.kernel.org> Signed-off-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bd71c453db91ecb464405411f2821d040f2a0d44 upstream. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3433adc8bd09fc9f29b8baddf33b4ecd1ecd2cdc upstream. We have NR_syscall syscalls from [0 .. NR_syscall-1]. However the check for invalid syscall number is "> NR_syscall" as opposed to >=. This off-by-one error erronesously allows "NR_syscall" to be treated as valid syscall causeing out-of-bounds access into syscall-call table ensuing a crash (holes within syscall table have a invalid-entry handler but this is beyond the array implementing the table). This problem showed up on v5.6 kernel when testing glibc 2.33 (v5.10 kernel capable, includng faccessat2 syscall 439). The v5.6 kernel has NR_syscalls=439 (0 to 438). Due to the bug, 439 passed by glibc was not handled as -ENOSYS but processed leading to a crash. Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/48 Reported-by: Shahab Vahedi <shahab@synopsys.com> Cc: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 00fdec98d9881bf5173af09aebd353ab3b9ac729 upstream. Trap handler for syscall tracing reads EFA (Exception Fault Address), in case strace wants PC of trap instruction (EFA is not part of pt_regs as of current code). However this EFA read is racy as it happens after dropping to pure kernel mode (re-enabling interrupts). A taken interrupt could context-switch, trigger a different task's trap, clobbering EFA for this execution context. Fix this by reading EFA early, before re-enabling interrupts. A slight side benefit is de-duplication of FAKE_RET_FROM_EXCPN in trap handler. The trap handler is common to both ARCompact and ARCv2 builds too. This just came out of code rework/review and no real problem was reported but is clearly a potential problem specially for strace. Cc: <stable@vger.kernel.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
avoids 1 MOV instruction in light of double load/store code Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I recently came upon a scenario where I would get a double fault machine check exception tiriggered by a kernel module. However the ensuing crash stacktrace (ksym lookup) was not working correctly. Turns out that machine check auto-disables MMU while modules are allocated in kernel vaddr spapce. This patch re-enables the MMU before start printing the stacktrace making stacktracing of modules work upon a fatal exception. Cc: stable@kernel.org Signed-off-by: Jose Abreu <joabreu@synopsys.com> Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> [vgupta: moved code into low level handler to avoid in 2 places]
This essentially removes ENTRY() assembler annotation for this symbol since it didn't have a pairing END() This in ahead of introducing cfi pseudo ops in ENTRY/END which expects paired cfi_startproc/cfi_endproc | ../arch/arc/kernel/entry.S: Assembler messages: | ../arch/arc/kernel/entry.S:270: Error: previous CFI entry not closed (missing .cfi_endproc) | ../scripts/Makefile.build:326: recipe for target 'arch/arc/kernel/entry-arcv2.o' failed | make[4]: *** [arch/arc/kernel/entry-arcv2.o] Error 1 Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
So finally after almost 8 years of dealing with .debug_frame, we are
finally switching to .eh_frame. The reason being stripped kernel
binaries had non-functional unwinder as .debug_frame was gone.
Also, in general .eh_frame seems more common way of doing unwinding.
This also folds a revert of f52e126cc747 ("ARC: unwind: ensure that
.debug_frame is generated (vs. .eh_frame)") to ensure that we start
getting .eh_frame
Reported-by: Daniel Mentz <danielmentz@google.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Bus errors from userspace on ARCompact based cores are handled by core as a high priority L2 interrupt but current code treated it as interrupt Handling an interrupt like exception is certainly not going to go unnoticed. (and it worked so far as we never saw a Bus error from userspace until IPPK guys tested a DDR controller with ECC error detection etc hence needed to explicitly trigger/handle such errors) - So move mem_service exception handler from common code into ARCv2 code. - In ARCompact code, define mem_service as L2 interrupt handler which just drops down to pure kernel mode and goes of to enqueue SIGBUS Reported-by: Nelson Pereira <npereira@synopsys.com> Tested-by: Ana Martins <amartins@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>