Re: [PATCH][v4] livepatch/ppc: Enable livepatching on powerpc
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2016-03-08 21:43:12
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On Thu, 3 Mar 2016 17:52:01 +0100 Petr Mladek [off-list ref] wrote:
From: Balbir Singh <bsingharora@gmail.com> Changelog v4: 1. Renamed klp_matchaddr() to klp_get_ftrace_location() and used it just to convert the function address. 2. Synced klp_write_module_reloc() with s390(); made it inline, no error message, return -ENOSYS 3. Added an error message when including powerpc/include/asm/livepatch.h without HAVE_LIVEPATCH 4. Update some comments. Changelog v3: 1. Moved -ENOSYS to -EINVAL in klp_write_module_reloc 2. Moved klp_matchaddr to use ftrace_location_range Changelog v2: 1. Implement review comments by Michael 2. The previous version compared _NIP from the wrong location to check for whether we are going to a patched location This applies on top of the patches posted by Michael https://patchwork.ozlabs.org/patch/589791/ It enables livepatching. This takes patch 6/8 and 7/8 of v8 as the base. (See the reference [1] below) and adds logic for checking offset ranges in livepatch with ftrace_location_range. I tested the sample in the livepatch Signed-off-by: Torsten Duwe <redacted> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> --- arch/powerpc/Kconfig | 3 +++ arch/powerpc/include/asm/livepatch.h | 47 +++++++++++++++++++++++++++++++++ arch/powerpc/kernel/Makefile | 1 + arch/powerpc/kernel/entry_64.S | 50 ++++++++++++++++++++++++++++++++++++ arch/powerpc/kernel/livepatch.c | 29 +++++++++++++++++++++ include/linux/ftrace.h | 1 + include/linux/livepatch.h | 2 ++ kernel/livepatch/core.c | 28 +++++++++++++++++--- kernel/trace/ftrace.c | 14 +++++++++-
For the changes to the ftrace files, add my: Acked-by: Steven Rostedt <rostedt@goodmis.org> You can take the rest. -- Steve
9 files changed, 171 insertions(+), 4 deletions(-) create mode 100644 arch/powerpc/include/asm/livepatch.h create mode 100644 arch/powerpc/kernel/livepatch.c
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diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index c2b340e23f62..fb13cd3e68f9 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h@@ -455,6 +455,7 @@ int ftrace_update_record(struct dyn_ftrace *rec, int enable); int ftrace_test_record(struct dyn_ftrace *rec, int enable); void ftrace_run_stop_machine(int command); unsigned long ftrace_location(unsigned long ip); +unsigned long ftrace_location_range(unsigned long start, unsigned long end); unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
quoted hunk ↗ jump to hunk
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 57a6eea84694..f4e6aae6ebe7 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c@@ -1533,7 +1533,19 @@ static int ftrace_cmp_recs(const void *a, const void *b) return 0; } -static unsigned long ftrace_location_range(unsigned long start, unsigned long end) +/** + * ftrace_location_range - return the first address of a traced location + * if it touches the given ip range + * @start: start of range to search. + * @end: end of range to search (inclusive). @end points to the last byte + * to check. + * + * Returns rec->ip if the related ftrace location is a least partly within + * the given address range. That is, the first address of the instruction + * that is either a NOP or call to the function tracer. It checks the ftrace + * internal tables to determine if the address belongs or not. + */ +unsigned long ftrace_location_range(unsigned long start, unsigned long end) { struct ftrace_page *pg; struct dyn_ftrace *rec;