diff options
| -rw-r--r-- | Documentation/trace/ftrace-design.txt | 4 | ||||
| -rw-r--r-- | kernel/trace/trace_syscalls.c | 21 |
2 files changed, 18 insertions, 7 deletions
diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt index 6fca17beee2..79fcafc7fd6 100644 --- a/Documentation/trace/ftrace-design.txt +++ b/Documentation/trace/ftrace-design.txt @@ -250,6 +250,10 @@ You need very few things to get the syscalls tracing in an arch. - If the system call table on this arch is more complicated than a simple array of addresses of the system calls, implement an arch_syscall_addr to return the address of a given system call. +- If the symbol names of the system calls do not match the function names on + this arch, define ARCH_HAS_SYSCALL_MATCH_SYM_NAME in asm/ftrace.h and + implement arch_syscall_match_sym_name with the appropriate logic to return + true if the function name corresponds with the symbol name. - Tag this arch as HAVE_SYSCALL_TRACEPOINTS. diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index af831545f65..86a23e7de03 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -60,6 +60,19 @@ extern struct syscall_metadata *__stop_syscalls_metadata[]; static struct syscall_metadata **syscalls_metadata; +#ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME +static inline bool arch_syscall_match_sym_name(const char *sym, const char *name) +{ + /* + * Only compare after the "sys" prefix. Archs that use + * syscall wrappers may have syscalls symbols aliases prefixed + * with "SyS" instead of "sys", leading to an unwanted + * mismatch. + */ + return !strcmp(sym + 3, name + 3); +} +#endif + static __init struct syscall_metadata * find_syscall_meta(unsigned long syscall) { @@ -73,13 +86,7 @@ find_syscall_meta(unsigned long syscall) kallsyms_lookup(syscall, NULL, NULL, NULL, str); for ( ; start < stop; start++) { - /* - * Only compare after the "sys" prefix. Archs that use - * syscall wrappers may have syscalls symbols aliases prefixed - * with "SyS" instead of "sys", leading to an unwanted - * mismatch. - */ - if ((*start)->name && !strcmp((*start)->name + 3, str + 3)) + if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name)) return *start; } return NULL; |