kernel.git/arch/powerpc/kernel/kprobes.c, branch linux-4.10.y

Replace with globally

2016-12-24T19:46:01Z

This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*' sed -i -e "s!$PATT!#include !" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro Signed-off-by: Linus Torvalds

powerpc/kprobes: Invoke handlers directly

2016-11-23T11:56:25Z

Invoke the kprobe handlers directly rather than through notify_die(), to reduce path taken for handling kprobes. Similar to commit 6f6343f53d13 ("kprobes/x86: Call exception handlers directly from do_int3/do_debug"). While at it, rename post_kprobe_handler() to kprobe_post_handler() for more uniform naming. Reported-by: Masami Hiramatsu Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman

powerpc: Add support for relative exception tables

2016-11-14T00:11:51Z

This halves the exception table size on 64-bit builds, and it allows build-time sorting of exception tables to work on relocated kernels. Signed-off-by: Nicholas Piggin [mpe: Minor asm fixups and bits to keep the selftests working] Signed-off-by: Michael Ellerman

powerpc: migrate exception table users off module.h and onto extable.h

2016-08-22T01:09:33Z

These files were only including module.h for exception table related functions. We've now separated that content out into its own file "extable.h" so now move over to that and avoid all the extra header content in module.h that we don't really need to compile these files. Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Paul Gortmaker Signed-off-by: Benjamin Herrenschmidt

powerpc/kprobes: Remove kretprobe_trampoline_holder.

2016-06-21T05:30:49Z

Fixes the following testsuite failure: $ sudo ./perf test -v kallsyms 1: vmlinux symtab matches kallsyms : --- start --- test child forked, pid 12489 Using /proc/kcore for kernel object code Looking at the vmlinux_path (8 entries long) Using /boot/vmlinux for symbols 0xc00000000003d300: diff name v: .kretprobe_trampoline_holder k: kretprobe_trampoline Maps only in vmlinux: c00000000086ca38-c000000000879b6c 87ca38 [kernel].text.unlikely c000000000879b6c-c000000000bf0000 889b6c [kernel].meminit.text c000000000bf0000-c000000000c53264 c00000 [kernel].init.text c000000000c53264-d000000004250000 c63264 [kernel].exit.text d000000004250000-d000000004450000 0 [libcrc32c] d000000004450000-d000000004620000 0 [xfs] d000000004620000-d000000004680000 0 [autofs4] d000000004680000-d0000000046e0000 0 [x_tables] d0000000046e0000-d000000004780000 0 [ip_tables] d000000004780000-d0000000047e0000 0 [rng_core] d0000000047e0000-ffffffffffffffff 0 [pseries_rng] Maps in vmlinux with a different name in kallsyms: Maps only in kallsyms: d000000000000000-f000000000000000 1000000000010000 [kernel.kallsyms] f000000000000000-ffffffffffffffff 3000000000010000 [kernel.kallsyms] test child finished with -1 ---- end ---- vmlinux symtab matches kallsyms: FAILED! The problem is that the kretprobe_trampoline symbol looks like this: $ eu-readelf -s /boot/vmlinux G kretprobe_trampoline 2431: c000000001302368 24 NOTYPE LOCAL DEFAULT 37 kretprobe_trampoline_holder 2432: c00000000003d300 8 FUNC LOCAL DEFAULT 1 .kretprobe_trampoline_holder 97543: c00000000003d300 0 NOTYPE GLOBAL DEFAULT 1 kretprobe_trampoline Its type is NOTYPE, and its size is 0, and this is a problem because symbol-elf.c:dso__load_sym skips function symbols that are not STT_FUNC or STT_GNU_IFUNC (this is determined by elf_sym__is_function). Even if the type is changed to STT_FUNC, when dso__load_sym calls symbols__fixup_duplicate, the kretprobe_trampoline symbol is dropped in favour of .kretprobe_trampoline_holder because the latter has non-zero size (as determined by choose_best_symbol). With this patch, all vmlinux symbols match /proc/kallsyms and the testcase passes. Commit c1c355ce14c0 ("x86/kprobes: Get rid of kretprobe_trampoline_holder()") gets rid of kretprobe_trampoline_holder altogether on x86. This commit does the same on powerpc. This change introduces no regressions on the perf and ftracetest testsuite results. Reviewed-by: Naveen N. Rao Signed-off-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman

powerpc: Define and use PPC64_ELF_ABI_v2/v1

2016-06-14T03:58:27Z

We're approaching 20 locations where we need to check for ELF ABI v2. That's fine, except the logic is a bit awkward, because we have to check that _CALL_ELF is defined and then what its value is. So check it once in asm/types.h and define PPC64_ELF_ABI_v2 when ELF ABI v2 is detected. We also have a few places where what we're really trying to check is that we are using the 64-bit v1 ABI, ie. function descriptors. So also add a #define for that, which simplifies several checks. Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman

powerpc: Replace __get_cpu_var uses

2014-11-03T01:12:32Z

This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt CC: Paul Mackerras Signed-off-by: Christoph Lameter [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman

powerpc/kprobes: Fix jprobes on ABI v2 (LE)

2014-06-24T04:05:55Z

In commit 721aeaa9 "Build little endian ppc64 kernel with ABIv2", we missed some updates required in the kprobes code to make jprobes work when the kernel is built with ABI v2. Firstly update arch_deref_entry_point() to do the right thing. Now that we have added ppc_global_function_entry() we can just always use that, it will do the right thing for 32 & 64 bit and ABI v1 & v2. Secondly we need to update the code that sets up the register state before calling the jprobe handler. On ABI v1 we setup r2 to hold the TOC, on ABI v2 we need to populate r12 with the function entry point address. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

doc: typo on word accounting in kprobes.c in mutliple architectures

2013-10-14T13:46:39Z

Signed-off-by: Anoop Thomas Mathew Signed-off-by: Jiri Kosina

powerpc: Move the single step enable code to a generic path

2013-06-20T06:55:09Z

This patch moves the single step enable code used by kprobe to a generic routine header so that, it can be re-used by other code, in this case, uprobes. No functional changes. Signed-off-by: Suzuki K. Poulose Cc: Ananth N Mavinakaynahalli Cc: Kumar Gala Cc: linuxppc-dev@ozlabs.org Acked-by: Ananth N Mavinakayanahalli Signed-off-by: Benjamin Herrenschmidt