kernel/arch/powerpc/include/asm/syscall.h, branch linux-5.1.y

syscalls: Remove start and number from syscall_set_arguments() args

2019-04-05T13:27:23Z

After removing the start and count arguments of syscall_get_arguments() it seems reasonable to remove them from syscall_set_arguments(). Note, as of today, there are no users of syscall_set_arguments(). But we are told that there will be soon. But for now, at least make it consistent with syscall_get_arguments(). Link: http://lkml.kernel.org/r/20190327222014.GA32540@altlinux.org Cc: Oleg Nesterov Cc: Kees Cook Cc: Andy Lutomirski Cc: Dominik Brodowski Cc: Dave Martin Cc: "Dmitry V. Levin" Cc: x86@kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-hexagon@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: nios2-dev@lists.rocketboards.org Cc: openrisc@lists.librecores.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-riscv@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: linux-xtensa@linux-xtensa.org Cc: linux-arch@vger.kernel.org Acked-by: Max Filippov # For xtensa changes Acked-by: Will Deacon # For the arm64 bits Reviewed-by: Thomas Gleixner # for x86 Reviewed-by: Dmitry V. Levin Signed-off-by: Steven Rostedt (VMware)

syscalls: Remove start and number from syscall_get_arguments() args

2019-04-05T13:26:43Z

At Linux Plumbers, Andy Lutomirski approached me and pointed out that the function call syscall_get_arguments() implemented in x86 was horribly written and not optimized for the standard case of passing in 0 and 6 for the starting index and the number of system calls to get. When looking at all the users of this function, I discovered that all instances pass in only 0 and 6 for these arguments. Instead of having this function handle different cases that are never used, simply rewrite it to return the first 6 arguments of a system call. This should help out the performance of tracing system calls by ptrace, ftrace and perf. Link: http://lkml.kernel.org/r/20161107213233.754809394@goodmis.org Cc: Oleg Nesterov Cc: Kees Cook Cc: Andy Lutomirski Cc: Dominik Brodowski Cc: Dave Martin Cc: "Dmitry V. Levin" Cc: x86@kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-hexagon@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: nios2-dev@lists.rocketboards.org Cc: openrisc@lists.librecores.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-riscv@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: linux-xtensa@linux-xtensa.org Cc: linux-arch@vger.kernel.org Acked-by: Paul Burton # MIPS parts Acked-by: Max Filippov # For xtensa changes Acked-by: Will Deacon # For the arm64 bits Reviewed-by: Thomas Gleixner # for x86 Reviewed-by: Dmitry V. Levin Reported-by: Andy Lutomirski Signed-off-by: Steven Rostedt (VMware)

powerpc: split compat syscall table out from native table

2018-12-21T03:46:50Z

PowerPC uses a syscall table with native and compat calls interleaved, which is a slightly simpler way to define two matching tables. As we move to having the tables generated, that advantage is no longer important, but the interleaved table gets in the way of using the same scripts as on the other archit- ectures. Split out a new compat_sys_call_table symbol that contains all the compat calls, and leave the main table for the nat- ive calls, to more closely match the method we use every- where else. Suggested-by: Arnd Bergmann Signed-off-by: Firoz Khan Signed-off-by: Michael Ellerman

powerpc: Change syscall_get_nr() to return int

2015-07-29T01:56:13Z

The documentation for syscall_get_nr() in asm-generic says: Note this returns int even on 64-bit machines. Only 32 bits of system call number can be meaningful. If the actual arch value is 64 bits, this truncates to 32 bits so 0xffffffff means -1. However our implementation was never updated to reflect this. Generally it's not important, but there is once case where it matters. For seccomp filter with SECCOMP_RET_TRACE, the tracer will set regs->gpr[0] to -1 to reject the syscall. When the task is a compat task, this means we end up with 0xffffffff in r0 because ptrace will zero extend the 32-bit value. If syscall_get_nr() returns an unsigned long, then a 64-bit kernel will see a positive value in r0 and will incorrectly allow the syscall through seccomp. Signed-off-by: Michael Ellerman Reviewed-by: Kees Cook

powerpc: Use orig_gpr3 in syscall_get_arguments()

2015-07-29T01:56:13Z

Currently syscall_get_arguments() is used by syscall tracepoints, and collect_syscall() which is used in some debugging as well as /proc/pid/syscall. The current implementation just copies regs->gpr[3 .. 5] out, which is fine for all the current use cases. When we enable seccomp filter, that will also start using syscall_get_arguments(). However for seccomp filter we want to use r3 as the return value of the syscall, and orig_gpr3 as the first parameter. This will allow seccomp to modify the return value in r3. To support this we need to modify syscall_get_arguments() to return orig_gpr3 instead of r3. This is safe for all uses because orig_gpr3 always contains the r3 value that was passed to the syscall. We store it in the syscall entry path and never modify it. Update syscall_set_arguments() while we're here, even though it's never used. Signed-off-by: Michael Ellerman Reviewed-by: Kees Cook

powerpc: Rework syscall_get_arguments() so there is only one loop

2015-07-29T01:56:12Z

Currently syscall_get_arguments() has two loops, one for compat and one for regular tasks. In prepartion for the next patch, which changes which registers we use, switch it to only have one loop, so we only have one place to update. Signed-off-by: Michael Ellerman Reviewed-by: Kees Cook

powerpc: Don't negate error in syscall_set_return_value()

2015-07-29T01:56:12Z

Currently the only caller of syscall_set_return_value() is seccomp filter, which is not enabled on powerpc. This means we have not noticed that our implementation of syscall_set_return_value() negates error, even though the value passed in is already negative. So remove the negation in syscall_set_return_value(), and expect the caller to do it like all other implementations do. Also add a comment about the ccr handling. Signed-off-by: Michael Ellerman Reviewed-by: Kees Cook

powerpc: Drop unused syscall_get_error()

2015-07-29T01:56:12Z

syscall_get_error() is unused, and never has been. It's also probably wrong, as it negates r3 before returning it, but that depends on what the caller is expecting. It also doesn't deal with compat, and doesn't deal with TIF_NOERROR. Although we could fix those, until it has a caller and it's clear what semantics the caller wants it's just untested code. So drop it. Signed-off-by: Michael Ellerman Reviewed-by: Kees Cook

powerpc: add little endian flag to syscall_get_arch()

2014-12-12T09:14:08Z

Since both ppc and ppc64 have LE variants which are now reported by uname, add that flag (__AUDIT_ARCH_LE) to syscall_get_arch() and add AUDIT_ARCH_PPC64LE variant. Without this, perf trace and auditctl fail. Mainline kernel reports ppc64le (per a058801) but there is no matching AUDIT_ARCH_PPC64LE. Since 32-bit PPC LE is not supported by audit, don't advertise it in AUDIT_ARCH_PPC* variants. See: https://www.redhat.com/archives/linux-audit/2014-August/msg00082.html https://www.redhat.com/archives/linux-audit/2014-December/msg00004.html Signed-off-by: Richard Guy Briggs Acked-by: Paul Moore Signed-off-by: Michael Ellerman

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

2014-10-21T14:48:56Z

Pull more powerpc updates from Michael Ellerman: "Here's some more updates for powerpc for 3.18. They are a bit late I know, though must are actually bug fixes. In my defence I nearly cut the top of my finger off last weekend in a gruesome bike maintenance accident, so I spent a good part of the week waiting around for doctors. True story, I can send photos if you like :) Probably the most interesting fix is the sys_call_table one, which enables syscall tracing for powerpc. There's a fix for HMI handling for old firmware, more endian fixes for firmware interfaces, more EEH fixes, Anton fixed our routine that gets the current stack pointer, and a few other misc bits" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (22 commits) powerpc: Only do dynamic DMA zone limits on platforms that need it powerpc: sync pseries_le_defconfig with pseries_defconfig powerpc: Add printk levels to setup_system output powerpc/vphn: NUMA node code expects big-endian powerpc/msi: Use WARN_ON() in msi bitmap selftests powerpc/msi: Fix the msi bitmap alignment tests powerpc/eeh: Block CFG upon frozen Shiner adapter powerpc/eeh: Don't collect logs on PE with blocked config space powerpc/eeh: Block PCI config access upon frozen PE powerpc/pseries: Drop config requests in EEH accessors powerpc/powernv: Drop config requests in EEH accessors powerpc/eeh: Rename flag EEH_PE_RESET to EEH_PE_CFG_BLOCKED powerpc/eeh: Fix condition for isolated state powerpc/pseries: Make CPU hotplug path endian safe powerpc/pseries: Use dump_stack instead of show_stack powerpc: Rename __get_SP() to current_stack_pointer() powerpc: Reimplement __get_SP() as a function not a define powerpc/numa: Add ability to disable and debug topology updates powerpc/numa: check error return from proc_create powerpc/powernv: Fallback to old HMI handling behavior for old firmware ...