diff mbox series

[bpf-next,v1,3/3] bpf: Disable exceptions when CONFIG_UNWINDER_FRAME_POINTER=y

Message ID 20230918143914.292526-4-memxor@gmail.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series Fixes for Exceptions | expand

Checks

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bpf/vmtest-bpf-next-PR success PR summary
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bpf/vmtest-bpf-next-VM_Test-1 pending Logs for build for aarch64 with gcc
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netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 9 this patch: 9
netdev/cc_maintainers warning 15 maintainers not CCed: bp@alien8.de tglx@linutronix.de jolsa@kernel.org haoluo@google.com davem@davemloft.net sdf@google.com mingo@redhat.com dsahern@kernel.org netdev@vger.kernel.org x86@kernel.org john.fastabend@gmail.com hpa@zytor.com kpsingh@kernel.org song@kernel.org dave.hansen@linux.intel.com
netdev/build_clang success Errors and warnings before: 1364 this patch: 1364
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1365 this patch: 1365
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 20 lines checked
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netdev/source_inline success Was 0 now: 0

Commit Message

Kumar Kartikeya Dwivedi Sept. 18, 2023, 2:39 p.m. UTC
The build with CONFIG_UNWINDER_FRAME_POINTER=y is broken for
current exceptions feature as it assumes ORC unwinder specific fields in
the unwind_state. Disable exceptions when frame_pointer unwinder is
enabled for now.

Fixes: fd5d27b70188 ("arch/x86: Implement arch_bpf_stack_walk")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 arch/x86/net/bpf_jit_comp.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Comments

Alexei Starovoitov Sept. 18, 2023, 3:47 p.m. UTC | #1
On Mon, Sep 18, 2023 at 7:39 AM Kumar Kartikeya Dwivedi
<memxor@gmail.com> wrote:
>
> The build with CONFIG_UNWINDER_FRAME_POINTER=y is broken for
> current exceptions feature as it assumes ORC unwinder specific fields in
> the unwind_state. Disable exceptions when frame_pointer unwinder is
> enabled for now.
>
> Fixes: fd5d27b70188 ("arch/x86: Implement arch_bpf_stack_walk")
> Reported-by: Eric Dumazet <edumazet@google.com>
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

Very weird that only this patch reached patchwork.
Could you resend and trim cc list significantly?
Kumar Kartikeya Dwivedi Sept. 18, 2023, 3:55 p.m. UTC | #2
On Mon, 18 Sept 2023 at 17:48, Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Mon, Sep 18, 2023 at 7:39 AM Kumar Kartikeya Dwivedi
> <memxor@gmail.com> wrote:
> >
> > The build with CONFIG_UNWINDER_FRAME_POINTER=y is broken for
> > current exceptions feature as it assumes ORC unwinder specific fields in
> > the unwind_state. Disable exceptions when frame_pointer unwinder is
> > enabled for now.
> >
> > Fixes: fd5d27b70188 ("arch/x86: Implement arch_bpf_stack_walk")
> > Reported-by: Eric Dumazet <edumazet@google.com>
> > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
>
> Very weird that only this patch reached patchwork.
> Could you resend and trim cc list significantly?

I have resent it with just BPF and you in To:.
But I think it's not with this patch, a lot of emails are not
appearing on the list.
diff mbox series

Patch

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 84005f2114e0..8c10d9abc239 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -3003,16 +3003,15 @@  void bpf_jit_free(struct bpf_prog *prog)
 bool bpf_jit_supports_exceptions(void)
 {
 	/* We unwind through both kernel frames (starting from within bpf_throw
-	 * call) and BPF frames. Therefore we require one of ORC or FP unwinder
-	 * to be enabled to walk kernel frames and reach BPF frames in the stack
-	 * trace.
+	 * call) and BPF frames. Therefore we require ORC unwinder to be enabled
+	 * to walk kernel frames and reach BPF frames in the stack trace.
 	 */
-	return IS_ENABLED(CONFIG_UNWINDER_ORC) || IS_ENABLED(CONFIG_UNWINDER_FRAME_POINTER);
+	return IS_ENABLED(CONFIG_UNWINDER_ORC);
 }
 
 void arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp), void *cookie)
 {
-#if defined(CONFIG_UNWINDER_ORC) || defined(CONFIG_UNWINDER_FRAME_POINTER)
+#if defined(CONFIG_UNWINDER_ORC)
 	struct unwind_state state;
 	unsigned long addr;