| Message ID | 20220829055223.24767-9-sv@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | objtool: Enable and implement --mcount option on powerpc | expand |
On Mon, Aug 29, 2022 at 11:22:15AM +0530, Sathvika Vasireddy wrote: > From: Christophe Leroy <christophe.leroy@csgroup.eu> > > find_insn() will return NULL in case of failure. Check insn in order > to avoid a kernel Oops for NULL pointer dereference. > > Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> > --- > tools/objtool/check.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/objtool/check.c b/tools/objtool/check.c > index 91678252a9b6..ed2fdfeb1d9c 100644 > --- a/tools/objtool/check.c > +++ b/tools/objtool/check.c > @@ -205,7 +205,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, > return false; > > insn = find_insn(file, func->sec, func->offset); > - if (!insn->func) > + if (!insn || !insn->func) > return false; I suppose this is ok, but how can the lookup for func->sec, func->offset *not* find an instruction ?!
Le 01/09/2022 à 21:20, Peter Zijlstra a écrit : > On Mon, Aug 29, 2022 at 11:22:15AM +0530, Sathvika Vasireddy wrote: >> From: Christophe Leroy <christophe.leroy@csgroup.eu> >> >> find_insn() will return NULL in case of failure. Check insn in order >> to avoid a kernel Oops for NULL pointer dereference. >> >> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> >> --- >> tools/objtool/check.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/objtool/check.c b/tools/objtool/check.c >> index 91678252a9b6..ed2fdfeb1d9c 100644 >> --- a/tools/objtool/check.c >> +++ b/tools/objtool/check.c >> @@ -205,7 +205,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, >> return false; >> >> insn = find_insn(file, func->sec, func->offset); >> - if (!insn->func) >> + if (!insn || !insn->func) >> return false; > > I suppose this is ok, but how can the lookup for func->sec, func->offset > *not* find an instruction ?! That happened to me at the begining when the port to powerpc was not fully functionnal. I guess that could also happen with a corrupted object file so better safe than sorry.
On Fri, Sep 02, 2022 at 08:06:28AM +0000, Christophe Leroy wrote: > > > Le 01/09/2022 à 21:20, Peter Zijlstra a écrit : > > On Mon, Aug 29, 2022 at 11:22:15AM +0530, Sathvika Vasireddy wrote: > >> From: Christophe Leroy <christophe.leroy@csgroup.eu> > >> > >> find_insn() will return NULL in case of failure. Check insn in order > >> to avoid a kernel Oops for NULL pointer dereference. > >> > >> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> > >> --- > >> tools/objtool/check.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/tools/objtool/check.c b/tools/objtool/check.c > >> index 91678252a9b6..ed2fdfeb1d9c 100644 > >> --- a/tools/objtool/check.c > >> +++ b/tools/objtool/check.c > >> @@ -205,7 +205,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, > >> return false; > >> > >> insn = find_insn(file, func->sec, func->offset); > >> - if (!insn->func) > >> + if (!insn || !insn->func) > >> return false; > > > > I suppose this is ok, but how can the lookup for func->sec, func->offset > > *not* find an instruction ?! > > That happened to me at the begining when the port to powerpc was not > fully functionnal. > > I guess that could also happen with a corrupted object file so better > safe than sorry. Fair enough. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 91678252a9b6..ed2fdfeb1d9c 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -205,7 +205,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, return false; insn = find_insn(file, func->sec, func->offset); - if (!insn->func) + if (!insn || !insn->func) return false; func_for_each_insn(file, func, insn) {