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yaml
---
r: 234433
b: refs/heads/master
c: b2d5549
h: refs/heads/master
i:
  234431: 21d26d6
v: v3
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Ian Munsie authored and Steven Rostedt committed Feb 8, 2011
1 parent 4894106 commit 4608a11
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Showing 3 changed files with 19 additions and 8 deletions.
2 changes: 1 addition & 1 deletion [refs]
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@@ -1,2 +1,2 @@
---
refs/heads/master: c763ba06bd9b5db2c46c36276c89103d92d2c604
refs/heads/master: b2d55496818d64310b9f5486d4eea76ea614d7f8
4 changes: 4 additions & 0 deletions trunk/Documentation/trace/ftrace-design.txt
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Expand Up @@ -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.


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21 changes: 14 additions & 7 deletions trunk/kernel/trace/trace_syscalls.c
Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
Expand All @@ -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;
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