This patchset adds support syscall event tracing for compat syscalls. Patch 1 removes the unnecessary syscall_nr field from syscall metadata, which was one of the obstacles for adding proper support for compat syscalls.
Patch 2 adds a method to distinguish handling of syscalls for compat tasks if an arch requires that. In disussions about an earlier version of these patches (http://marc.info/?l=linux-mips&m=147259973128606&w=2) it was suggested to use audit arch for detecting syscall type. After analysing the code for various arches it seemed to me that this would add an unnecessary complexity (as would require extra APIs to enumerate and map all audit arch types) and I've just simply used compat task status to determine call type. I cannot see any added value from using the audit arch type in this context. Patch 3 removes arch_syscall_match_sym_name function which was only redefined by ppc and replaces it with a a more simple solution that makes it easy to modify the method later without changing arch-specific method Patch 4 (3 in pre rev 4) add compat syscall metadata - this is mostly a copy of a set of macros for generating metadata for standard syscalls. Further patches add arch-specific methods required for differentiating between standard and compat syscalls as well as for finding syscall addresses from inside syscall tables. I have tried to keep the tracing system working for bisections - and most things work as previously until arch-specific patch is applied. The only exception here is x86 which had extra methods to prevent incorrect syscall reporting for compat tasks - this may happen after patch 2 is applied and without x86/tracing patch. version 4: - fix an invalid exit handler registration - drop arch_syscall_match_sym_name as only used by ppc and replace it with a single #define for string offset (suggested by Michael Ellerman) - x86: reword and bring back a comment on ia32/x86_64 syscall number differences (suggested by tglx) - arm64: drop __NR_compat_syscalls (suggested by Will Deacon) version 3: - rebase on top of linux-next-20161011 - tile: change in_compat_syscall to is_compat_task (suggested and signed-off by Chris Metcalf) Marcin Nowakowski (12): tracing/syscalls: remove syscall_nr from syscall metadata tracing/syscalls: add handling for compat tasks tracing/syscalls: drop arch_syscall_match_sym_name tracing/syscalls: add compat syscall metadata syscall/tracing: allow arch to override syscall_get_nr for ftrace x86/tracing: fix compat syscall handling s390/tracing: fix compat syscall handling arm64/tracing: fix compat syscall handling powerpc/tracing: fix compat syscall handling tile/tracing: fix compat syscall handling sparc/tracing: fix compat syscall handling parisc/tracing: fix compat syscall handling Documentation/trace/ftrace-design.txt | 4 - arch/arm64/include/asm/ftrace.h | 12 +- arch/arm64/include/asm/unistd.h | 2 +- arch/arm64/include/asm/unistd32.h | 2 +- arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/entry.S | 2 +- arch/arm64/kernel/ftrace.c | 16 ++ arch/arm64/kernel/sys32.c | 4 +- arch/mips/kernel/ftrace.c | 4 +- arch/parisc/include/asm/ftrace.h | 10 ++ arch/parisc/kernel/Makefile | 1 + arch/parisc/kernel/ftrace.c | 15 ++ arch/powerpc/include/asm/ftrace.h | 24 +-- arch/powerpc/kernel/ftrace.c | 6 +- arch/s390/include/asm/ftrace.h | 11 ++ arch/s390/include/asm/syscall.h | 1 + arch/s390/kernel/Makefile | 1 + arch/s390/kernel/ftrace.c | 12 ++ arch/sparc/include/asm/ftrace.h | 10 ++ arch/sparc/kernel/Makefile | 1 + arch/sparc/kernel/ftrace.c | 14 ++ arch/tile/include/asm/ftrace.h | 10 ++ arch/tile/kernel/Makefile | 1 + arch/tile/kernel/ftrace.c | 13 ++ arch/x86/include/asm/ftrace.h | 14 +- arch/x86/include/asm/syscall.h | 9 ++ arch/x86/kernel/ftrace.c | 23 +++ include/linux/compat.h | 74 ++++++++++ include/linux/ftrace.h | 2 +- include/linux/syscalls.h | 1 - include/trace/syscall.h | 2 - kernel/trace/trace.h | 17 ++- kernel/trace/trace_syscalls.c | 271 +++++++++++++++++++++------------- 33 files changed, 432 insertions(+), 158 deletions(-) -- 2.7.4