* Re: [PATCH] bpf: mark get_entry_ip as __maybe_unused [not found] <20221103150303.974028-1-rabenstein@cs.fau.de> @ 2022-11-03 15:32 ` Jonas Rabenstein 2022-11-04 23:03 ` Daniel Borkmann 2022-11-07 8:56 ` Greg KH 0 siblings, 2 replies; 6+ messages in thread From: Jonas Rabenstein @ 2022-11-03 15:32 UTC (permalink / raw) To: stable Cc: Jiri Olsa, Song Liu, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Yonghong Song, John Fastabend, KP Singh, Stanislav Fomichev, Hao Luo, Steven Rostedt, Masami Hiramatsu, bpf, linux-kernel Hi again, after sending this out, I noticed this is only a problem in the stable versions (starting from v6.0.3), as c09eb2e578eb1668bbc has been applied (as 03f148c159a250dd454) but not 0e253f7e558a3e250902 ("bpf: Return value in kprobe get_func_ip only for entry address") which makes always use of get_entry_ip. I therefore think, 0e253f7e558a3e250902 needs to be added to the stable v6.0 series as well as otherwise it can't be compiled with -Werror if CONFIG_X6_KERNEL_IBT is set but CONFIG_FPROBE isn't. - Jonas On Thu, Nov 03, 2022 at 04:03:03PM +0100, Jonas Rabenstein wrote: > Commit c09eb2e578eb1668bbc ("bpf: Adjust kprobe_multi entry_ip > for CONFIG_X86_KERNEL_IBT") introduced the get_entry_ip() function. > Depending on CONFIG_X86_KERNEL_IBT it is a static function or only > a macro definition. The only user of this symbol so far is in > kprobe_multi_link_handler() if CONFIG_FPROBE is enabled. > If CONFIG_FROBE is not set, the symbol is not used and - depending > on CONFIG_X86_KERNEL_IBT - a warning for get_entry_ip() is emitted. > To solve this, the function should be marked as __maybe_unused. > > Signed-off-by: Jonas Rabenstein <rabenstein@cs.fau.de> > --- > kernel/trace/bpf_trace.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index f2d8d070d024..19131aae0bc3 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -1032,7 +1032,7 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { > }; > > #ifdef CONFIG_X86_KERNEL_IBT > -static unsigned long get_entry_ip(unsigned long fentry_ip) > +static unsigned long __maybe_unused get_entry_ip(unsigned long fentry_ip) > { > u32 instr; > > -- > 2.37.4 > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] bpf: mark get_entry_ip as __maybe_unused 2022-11-03 15:32 ` [PATCH] bpf: mark get_entry_ip as __maybe_unused Jonas Rabenstein @ 2022-11-04 23:03 ` Daniel Borkmann 2022-11-07 8:56 ` Greg KH 1 sibling, 0 replies; 6+ messages in thread From: Daniel Borkmann @ 2022-11-04 23:03 UTC (permalink / raw) To: Jonas Rabenstein, stable Cc: Jiri Olsa, Song Liu, Alexei Starovoitov, Andrii Nakryiko, Martin KaFai Lau, Yonghong Song, John Fastabend, KP Singh, Stanislav Fomichev, Hao Luo, Steven Rostedt, Masami Hiramatsu, bpf, linux-kernel, gregkh On 11/3/22 4:32 PM, Jonas Rabenstein wrote: > Hi again, > after sending this out, I noticed this is only a problem in the stable > versions (starting from v6.0.3), as c09eb2e578eb1668bbc has been applied (as > 03f148c159a250dd454) but not 0e253f7e558a3e250902 ("bpf: Return value in kprobe > get_func_ip only for entry address") which makes always use of get_entry_ip. > I therefore think, 0e253f7e558a3e250902 needs to be added to the stable v6.0 > series as well as otherwise it can't be compiled with -Werror if > CONFIG_X6_KERNEL_IBT is set but CONFIG_FPROBE isn't. Thanks for the info, Jonas. Added Greg wrt stable cherry-pick. > On Thu, Nov 03, 2022 at 04:03:03PM +0100, Jonas Rabenstein wrote: >> Commit c09eb2e578eb1668bbc ("bpf: Adjust kprobe_multi entry_ip >> for CONFIG_X86_KERNEL_IBT") introduced the get_entry_ip() function. >> Depending on CONFIG_X86_KERNEL_IBT it is a static function or only >> a macro definition. The only user of this symbol so far is in >> kprobe_multi_link_handler() if CONFIG_FPROBE is enabled. >> If CONFIG_FROBE is not set, the symbol is not used and - depending >> on CONFIG_X86_KERNEL_IBT - a warning for get_entry_ip() is emitted. >> To solve this, the function should be marked as __maybe_unused. >> >> Signed-off-by: Jonas Rabenstein <rabenstein@cs.fau.de> >> --- >> kernel/trace/bpf_trace.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c >> index f2d8d070d024..19131aae0bc3 100644 >> --- a/kernel/trace/bpf_trace.c >> +++ b/kernel/trace/bpf_trace.c >> @@ -1032,7 +1032,7 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { >> }; >> >> #ifdef CONFIG_X86_KERNEL_IBT >> -static unsigned long get_entry_ip(unsigned long fentry_ip) >> +static unsigned long __maybe_unused get_entry_ip(unsigned long fentry_ip) >> { >> u32 instr; >> >> -- >> 2.37.4 >> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] bpf: mark get_entry_ip as __maybe_unused 2022-11-03 15:32 ` [PATCH] bpf: mark get_entry_ip as __maybe_unused Jonas Rabenstein 2022-11-04 23:03 ` Daniel Borkmann @ 2022-11-07 8:56 ` Greg KH 2022-11-07 9:29 ` Greg KH 1 sibling, 1 reply; 6+ messages in thread From: Greg KH @ 2022-11-07 8:56 UTC (permalink / raw) To: Jonas Rabenstein Cc: stable, Jiri Olsa, Song Liu, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Yonghong Song, John Fastabend, KP Singh, Stanislav Fomichev, Hao Luo, Steven Rostedt, Masami Hiramatsu, bpf, linux-kernel On Thu, Nov 03, 2022 at 04:32:47PM +0100, Jonas Rabenstein wrote: > Hi again, > after sending this out, I noticed this is only a problem in the stable > versions (starting from v6.0.3), as c09eb2e578eb1668bbc has been applied (as > 03f148c159a250dd454) but not 0e253f7e558a3e250902 ("bpf: Return value in kprobe > get_func_ip only for entry address") which makes always use of get_entry_ip. > I therefore think, 0e253f7e558a3e250902 needs to be added to the stable v6.0 > series as well as otherwise it can't be compiled with -Werror if > CONFIG_X6_KERNEL_IBT is set but CONFIG_FPROBE isn't. Ok, now queued up, thanks. greg k-h ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] bpf: mark get_entry_ip as __maybe_unused 2022-11-07 8:56 ` Greg KH @ 2022-11-07 9:29 ` Greg KH 2022-11-07 9:48 ` Jonas Rabenstein 0 siblings, 1 reply; 6+ messages in thread From: Greg KH @ 2022-11-07 9:29 UTC (permalink / raw) To: Jonas Rabenstein Cc: stable, Jiri Olsa, Song Liu, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Yonghong Song, John Fastabend, KP Singh, Stanislav Fomichev, Hao Luo, Steven Rostedt, Masami Hiramatsu, bpf, linux-kernel On Mon, Nov 07, 2022 at 09:56:42AM +0100, Greg KH wrote: > On Thu, Nov 03, 2022 at 04:32:47PM +0100, Jonas Rabenstein wrote: > > Hi again, > > after sending this out, I noticed this is only a problem in the stable > > versions (starting from v6.0.3), as c09eb2e578eb1668bbc has been applied (as > > 03f148c159a250dd454) but not 0e253f7e558a3e250902 ("bpf: Return value in kprobe > > get_func_ip only for entry address") which makes always use of get_entry_ip. > > I therefore think, 0e253f7e558a3e250902 needs to be added to the stable v6.0 > > series as well as otherwise it can't be compiled with -Werror if > > CONFIG_X6_KERNEL_IBT is set but CONFIG_FPROBE isn't. > > Ok, now queued up, thanks. Oops, this breaks the build, now dropping. greg k-h ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] bpf: mark get_entry_ip as __maybe_unused 2022-11-07 9:29 ` Greg KH @ 2022-11-07 9:48 ` Jonas Rabenstein 2022-11-07 9:51 ` Greg KH 0 siblings, 1 reply; 6+ messages in thread From: Jonas Rabenstein @ 2022-11-07 9:48 UTC (permalink / raw) To: Greg KH Cc: stable, Jiri Olsa, Song Liu, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Yonghong Song, John Fastabend, KP Singh, Stanislav Fomichev, Hao Luo, Steven Rostedt, Masami Hiramatsu, bpf, linux-kernel On Mon, Nov 07, 2022 at 10:29:55AM +0100, Greg KH wrote: > On Mon, Nov 07, 2022 at 09:56:42AM +0100, Greg KH wrote: > > On Thu, Nov 03, 2022 at 04:32:47PM +0100, Jonas Rabenstein wrote: > > > Hi again, > > > after sending this out, I noticed this is only a problem in the stable > > > versions (starting from v6.0.3), as c09eb2e578eb1668bbc has been applied (as > > > 03f148c159a250dd454) but not 0e253f7e558a3e250902 ("bpf: Return value in kprobe > > > get_func_ip only for entry address") which makes always use of get_entry_ip. > > > I therefore think, 0e253f7e558a3e250902 needs to be added to the stable v6.0 > > > series as well as otherwise it can't be compiled with -Werror if > > > CONFIG_X6_KERNEL_IBT is set but CONFIG_FPROBE isn't. > > > > Ok, now queued up, thanks. > > Oops, this breaks the build, now dropping. Sorry, 0e253f7e558a3e250902 ("bpf: Return value in kprobe get_func_ip only for entry address") uses the macro KPROBE_FLAG_ON_FUNC_ENTRY that was introduced in bf7a87f1075f67c286f7 ("kprobes: Add new KPROBE_FLAG_ON_FUNC_ENTRY kprobe flag"). Applying those on top of v6.0.7 fixes the original compilation problem (CONFIG_X6_KERNEL_IBT but !CONFIG_FPROBE) and should not break anything - jonas > > greg k-h ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] bpf: mark get_entry_ip as __maybe_unused 2022-11-07 9:48 ` Jonas Rabenstein @ 2022-11-07 9:51 ` Greg KH 0 siblings, 0 replies; 6+ messages in thread From: Greg KH @ 2022-11-07 9:51 UTC (permalink / raw) To: Jonas Rabenstein Cc: stable, Jiri Olsa, Song Liu, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Yonghong Song, John Fastabend, KP Singh, Stanislav Fomichev, Hao Luo, Steven Rostedt, Masami Hiramatsu, bpf, linux-kernel On Mon, Nov 07, 2022 at 10:48:49AM +0100, Jonas Rabenstein wrote: > On Mon, Nov 07, 2022 at 10:29:55AM +0100, Greg KH wrote: > > On Mon, Nov 07, 2022 at 09:56:42AM +0100, Greg KH wrote: > > > On Thu, Nov 03, 2022 at 04:32:47PM +0100, Jonas Rabenstein wrote: > > > > Hi again, > > > > after sending this out, I noticed this is only a problem in the stable > > > > versions (starting from v6.0.3), as c09eb2e578eb1668bbc has been applied (as > > > > 03f148c159a250dd454) but not 0e253f7e558a3e250902 ("bpf: Return value in kprobe > > > > get_func_ip only for entry address") which makes always use of get_entry_ip. > > > > I therefore think, 0e253f7e558a3e250902 needs to be added to the stable v6.0 > > > > series as well as otherwise it can't be compiled with -Werror if > > > > CONFIG_X6_KERNEL_IBT is set but CONFIG_FPROBE isn't. > > > > > > Ok, now queued up, thanks. > > > > Oops, this breaks the build, now dropping. > Sorry, 0e253f7e558a3e250902 ("bpf: Return value in kprobe get_func_ip only for > entry address") uses the macro KPROBE_FLAG_ON_FUNC_ENTRY that was introduced > in bf7a87f1075f67c286f7 ("kprobes: Add new KPROBE_FLAG_ON_FUNC_ENTRY kprobe > flag"). Applying those on top of v6.0.7 fixes the original compilation problem > (CONFIG_X6_KERNEL_IBT but !CONFIG_FPROBE) and should not break anything Please submit a set of backports that you have verified works properly so that I know it is correct. thanks, greg k-h ^ permalink raw reply [flat|nested] 6+ messages in thread
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[not found] <20221103150303.974028-1-rabenstein@cs.fau.de>
2022-11-03 15:32 ` [PATCH] bpf: mark get_entry_ip as __maybe_unused Jonas Rabenstein
2022-11-04 23:03 ` Daniel Borkmann
2022-11-07 8:56 ` Greg KH
2022-11-07 9:29 ` Greg KH
2022-11-07 9:48 ` Jonas Rabenstein
2022-11-07 9:51 ` Greg KH
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