Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | [PATCH 02/12] tracing/kprobes: Add fetch{,_size} member into symbol and deref fetch method | Date | Wed, 3 Jul 2013 21:35:36 +0900 |
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From: Hyeoncheol Lee <cheol.lee@lge.com>
Those symbol and deref fetch methods access a memory region but they assume it's a kernel memory since uprobes does not support them.
Add ->fetch and ->fetch_size member in order to provide a proper access method for supporting uprobes.
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Hyeoncheol Lee <cheol.lee@lge.com> [namhyung@kernel.org: Split original patch into pieces as requested] Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- kernel/trace/trace_probe.c | 48 ++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 42 insertions(+), 6 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index c58c25d81591..c123a890c5b1 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -93,6 +93,8 @@ struct symbol_cache { char *symbol; long offset; unsigned long addr; + fetch_func_t fetch; + fetch_func_t fetch_size; }; static unsigned long update_symbol_cache(struct symbol_cache *sc) @@ -139,18 +141,29 @@ __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, \ { \ struct symbol_cache *sc = data; \ if (sc->addr) \ - fetch_memory_##type(regs, (void *)sc->addr, dest); \ + sc->fetch(regs, (void *)sc->addr, dest); \ else \ *(type *)dest = 0; \ } DEFINE_BASIC_FETCH_FUNCS(symbol) DEFINE_FETCH_symbol(string) -DEFINE_FETCH_symbol(string_size) + +__kprobes void FETCH_FUNC_NAME(symbol, string_size)(struct pt_regs *regs, + void *data, void *dest) +{ + struct symbol_cache *sc = data; + if (sc->addr && sc->fetch_size) + sc->fetch_size(regs, (void *)sc->addr, dest); + else + *(string_size *)dest = 0; +} /* Dereference memory access function */ struct deref_fetch_param { struct fetch_param orig; long offset; + fetch_func_t fetch; + fetch_func_t fetch_size; }; #define DEFINE_FETCH_deref(type) \ @@ -162,13 +175,26 @@ __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ call_fetch(&dprm->orig, regs, &addr); \ if (addr) { \ addr += dprm->offset; \ - fetch_memory_##type(regs, (void *)addr, dest); \ + dprm->fetch(regs, (void *)addr, dest); \ } else \ *(type *)dest = 0; \ } DEFINE_BASIC_FETCH_FUNCS(deref) DEFINE_FETCH_deref(string) -DEFINE_FETCH_deref(string_size) + +__kprobes void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, + void *data, void *dest) +{ + struct deref_fetch_param *dprm = data; + unsigned long addr; + + call_fetch(&dprm->orig, regs, &addr); + if (addr && dprm->fetch_size) { + addr += dprm->offset; + dprm->fetch_size(regs, (void *)addr, dest); + } else + *(string_size *)dest = 0; +} static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) { @@ -410,13 +436,20 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, f->fn = t->fetch[FETCH_MTD_memory]; f->data = (void *)param; } else { + struct symbol_cache *sc; + ret = traceprobe_split_symbol_offset(arg + 1, &offset); if (ret) break; - f->data = alloc_symbol_cache(arg + 1, offset); - if (f->data) + sc = alloc_symbol_cache(arg + 1, offset); + if (sc) { f->fn = t->fetch[FETCH_MTD_symbol]; + sc->fetch = t->fetch[FETCH_MTD_memory]; + sc->fetch_size = get_fetch_size_function(t, + sc->fetch, ttbl); + f->data = sc; + } } break; @@ -448,6 +481,9 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t, return -ENOMEM; dprm->offset = offset; + dprm->fetch = t->fetch[FETCH_MTD_memory]; + dprm->fetch_size = get_fetch_size_function(t, + dprm->fetch, ttbl); ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, is_kprobe); if (ret) -- 1.7.11.7
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