* [PATCH] objtool: Move objtool_file struct off the stack
@ 2019-03-14 15:25 Josh Poimboeuf
2019-03-14 15:31 ` moosotc
0 siblings, 1 reply; 3+ messages in thread
From: Josh Poimboeuf @ 2019-03-14 15:25 UTC (permalink / raw)
To: x86; +Cc: linux-kernel, Peter Zijlstra, moosotc
Objtool uses over 512k of stack, thanks to the hash table embedded in
the objtool_file struct. This causes an unnecessarily large stack
allocation and breaks users with low stack limits.
Move the struct off the stack.
Fixes: 042ba73fe7eb ("objtool: Add several performance improvements")
Reported-by: Vassili Karpov <moosotc@gmail.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
tools/objtool/check.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 0414a0d52262..91c4799192e1 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2184,9 +2184,10 @@ static void cleanup(struct objtool_file *file)
elf_close(file->elf);
}
+struct objtool_file file;
+
int check(const char *_objname, bool orc)
{
- struct objtool_file file;
int ret, warnings = 0;
objname = _objname;
--
2.17.2
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] objtool: Move objtool_file struct off the stack
2019-03-14 15:25 [PATCH] objtool: Move objtool_file struct off the stack Josh Poimboeuf
@ 2019-03-14 15:31 ` moosotc
2019-03-14 16:15 ` Josh Poimboeuf
0 siblings, 1 reply; 3+ messages in thread
From: moosotc @ 2019-03-14 15:31 UTC (permalink / raw)
To: Josh Poimboeuf; +Cc: x86, linux-kernel, Peter Zijlstra
Josh Poimboeuf <jpoimboe@redhat.com> writes:
> Objtool uses over 512k of stack, thanks to the hash table embedded in
> the objtool_file struct. This causes an unnecessarily large stack
> allocation and breaks users with low stack limits.
>
> Move the struct off the stack.
>
> Fixes: 042ba73fe7eb ("objtool: Add several performance improvements")
> Reported-by: Vassili Karpov <moosotc@gmail.com>
> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> ---
> tools/objtool/check.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index 0414a0d52262..91c4799192e1 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -2184,9 +2184,10 @@ static void cleanup(struct objtool_file *file)
> elf_close(file->elf);
> }
>
> +struct objtool_file file;
> +
Maybe it also deserves a "static" storage duration (if nothing else this
would prevent possible name clashes)?
> int check(const char *_objname, bool orc)
> {
> - struct objtool_file file;
> int ret, warnings = 0;
>
> objname = _objname;
--
mailto:moosotc@gmail.com
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] objtool: Move objtool_file struct off the stack
2019-03-14 15:31 ` moosotc
@ 2019-03-14 16:15 ` Josh Poimboeuf
0 siblings, 0 replies; 3+ messages in thread
From: Josh Poimboeuf @ 2019-03-14 16:15 UTC (permalink / raw)
To: moosotc; +Cc: x86, linux-kernel, Peter Zijlstra
On Thu, Mar 14, 2019 at 06:31:37PM +0300, moosotc@gmail.com wrote:
> Josh Poimboeuf <jpoimboe@redhat.com> writes:
>
> > Objtool uses over 512k of stack, thanks to the hash table embedded in
> > the objtool_file struct. This causes an unnecessarily large stack
> > allocation and breaks users with low stack limits.
> >
> > Move the struct off the stack.
> >
> > Fixes: 042ba73fe7eb ("objtool: Add several performance improvements")
> > Reported-by: Vassili Karpov <moosotc@gmail.com>
> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> > ---
> > tools/objtool/check.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> > index 0414a0d52262..91c4799192e1 100644
> > --- a/tools/objtool/check.c
> > +++ b/tools/objtool/check.c
> > @@ -2184,9 +2184,10 @@ static void cleanup(struct objtool_file *file)
> > elf_close(file->elf);
> > }
> >
> > +struct objtool_file file;
> > +
>
> Maybe it also deserves a "static" storage duration (if nothing else this
> would prevent possible name clashes)?
Yeah, good point.
>
> > int check(const char *_objname, bool orc)
> > {
> > - struct objtool_file file;
> > int ret, warnings = 0;
> >
> > objname = _objname;
>
> --
> mailto:moosotc@gmail.com
--
Josh
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-03-14 15:25 [PATCH] objtool: Move objtool_file struct off the stack Josh Poimboeuf
2019-03-14 15:31 ` moosotc
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