Message ID | 20221212091136.969960-1-hengqi.chen@gmail.com (mailing list archive) |
---|---|
State | Superseded |
Delegated to: | BPF |
Headers | show |
Series | [bpf-next] libbpf: Add LoongArch support to bpf_tracing.h | expand |
On Mon, Dec 12, 2022 at 1:11 AM Hengqi Chen <hengqi.chen@gmail.com> wrote: > > Add PT_REGS macros for LoongArch64. > > Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> > --- > tools/lib/bpf/bpf_tracing.h | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h > index 2972dc25ff72..2d7da1caa961 100644 > --- a/tools/lib/bpf/bpf_tracing.h > +++ b/tools/lib/bpf/bpf_tracing.h > @@ -32,6 +32,9 @@ > #elif defined(__TARGET_ARCH_arc) > #define bpf_target_arc > #define bpf_target_defined > +#elif defined(__TARGET_ARCH_loongarch) > + #define bpf_target_loongarch > + #define bpf_target_defined > #else > > /* Fall back to what the compiler says */ > @@ -62,6 +65,9 @@ > #elif defined(__arc__) > #define bpf_target_arc > #define bpf_target_defined > +#elif defined(__loongarch__) && __loongarch_grlen == 64 > + #define bpf_target_loongarch > + #define bpf_target_defined > #endif /* no compiler target */ > > #endif > @@ -258,6 +264,21 @@ struct pt_regs___arm64 { > /* arc does not select ARCH_HAS_SYSCALL_WRAPPER. */ > #define PT_REGS_SYSCALL_REGS(ctx) ctx > > +#elif defined(bpf_target_loongarch) > + > +#define __PT_PARM1_REG regs[5] > +#define __PT_PARM2_REG regs[6] > +#define __PT_PARM3_REG regs[7] > +#define __PT_PARM4_REG regs[8] > +#define __PT_PARM5_REG regs[9] > +#define __PT_RET_REG regs[1] > +#define __PT_FP_REG regs[22] > +#define __PT_RC_REG regs[4] > +#define __PT_SP_REG regs[3] > +#define __PT_IP_REG csr_era > +/* loongarch does not select ARCH_HAS_SYSCALL_WRAPPER. */ > +#define PT_REGS_SYSCALL_REGS(ctx) ctx Is there some online documentation explaining this architecture's calling conventions? It would be useful to include that as a comment to be able to refer back to it. On a related note, are there any syscall specific calling convention differences, similar to PT_REGS_PARM1_SYSCALL for arm64 or PT_REGS_PARM4_SYSCALL for x86-64? > + > #endif > > #if defined(bpf_target_defined) > -- > 2.31.1
On Mon, Dec 12, 2022 at 4:17 PM Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote: > > On Mon, Dec 12, 2022 at 1:11 AM Hengqi Chen <hengqi.chen@gmail.com> wrote: > > > > Add PT_REGS macros for LoongArch64. > > > > Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> > > --- > > tools/lib/bpf/bpf_tracing.h | 21 +++++++++++++++++++++ > > 1 file changed, 21 insertions(+) > > > > diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h > > index 2972dc25ff72..2d7da1caa961 100644 > > --- a/tools/lib/bpf/bpf_tracing.h > > +++ b/tools/lib/bpf/bpf_tracing.h > > @@ -32,6 +32,9 @@ > > #elif defined(__TARGET_ARCH_arc) > > #define bpf_target_arc > > #define bpf_target_defined > > +#elif defined(__TARGET_ARCH_loongarch) > > + #define bpf_target_loongarch > > + #define bpf_target_defined > > #else > > > > /* Fall back to what the compiler says */ > > @@ -62,6 +65,9 @@ > > #elif defined(__arc__) > > #define bpf_target_arc > > #define bpf_target_defined > > +#elif defined(__loongarch__) && __loongarch_grlen == 64 > > + #define bpf_target_loongarch > > + #define bpf_target_defined > > #endif /* no compiler target */ > > > > #endif > > @@ -258,6 +264,21 @@ struct pt_regs___arm64 { > > /* arc does not select ARCH_HAS_SYSCALL_WRAPPER. */ > > #define PT_REGS_SYSCALL_REGS(ctx) ctx > > > > +#elif defined(bpf_target_loongarch) > > + > > +#define __PT_PARM1_REG regs[5] > > +#define __PT_PARM2_REG regs[6] > > +#define __PT_PARM3_REG regs[7] > > +#define __PT_PARM4_REG regs[8] > > +#define __PT_PARM5_REG regs[9] > > +#define __PT_RET_REG regs[1] > > +#define __PT_FP_REG regs[22] > > +#define __PT_RC_REG regs[4] > > +#define __PT_SP_REG regs[3] > > +#define __PT_IP_REG csr_era > > +/* loongarch does not select ARCH_HAS_SYSCALL_WRAPPER. */ > > +#define PT_REGS_SYSCALL_REGS(ctx) ctx > > Is there some online documentation explaining this architecture's > calling conventions? It would be useful to include that as a comment > to be able to refer back to it. On a related note, are there any > syscall specific calling convention differences, similar to > PT_REGS_PARM1_SYSCALL for arm64 or PT_REGS_PARM4_SYSCALL for x86-64? > Ok, I think [0] would be a good resource, please add a link to it in the comment. But also it seems like PARM1-5 should map to regs[6] through regs[10] (not regs[5] - regs[9] that you have here). And BTW, seems like architecture supports passing more than five, PARM6 would be regs[11]. I've been wanting to add 6th+ argument to libbpf macros' for a while (it came up in x86-64 world for uprobes as well), so if you have cycles, please consider helping with that as well. Also I see orig_a0 in struct pt_regs, which seems suspiciously similar to arm64's PT_REGS_PARM1_SYSCALL's use of orig_x0, please check about that as well. As I said, syscalls usually have some additional quirks. [0] https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html > > + > > #endif > > > > #if defined(bpf_target_defined) > > -- > > 2.31.1
On 2022/12/14 06:09, Andrii Nakryiko wrote: > On Mon, Dec 12, 2022 at 4:17 PM Andrii Nakryiko > <andrii.nakryiko@gmail.com> wrote: >> >> On Mon, Dec 12, 2022 at 1:11 AM Hengqi Chen <hengqi.chen@gmail.com> wrote: >>> >>> Add PT_REGS macros for LoongArch64. >>> >>> Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> >>> --- >>> tools/lib/bpf/bpf_tracing.h | 21 +++++++++++++++++++++ >>> 1 file changed, 21 insertions(+) >>> >>> diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h >>> index 2972dc25ff72..2d7da1caa961 100644 >>> --- a/tools/lib/bpf/bpf_tracing.h >>> +++ b/tools/lib/bpf/bpf_tracing.h >>> @@ -32,6 +32,9 @@ >>> #elif defined(__TARGET_ARCH_arc) >>> #define bpf_target_arc >>> #define bpf_target_defined >>> +#elif defined(__TARGET_ARCH_loongarch) >>> + #define bpf_target_loongarch >>> + #define bpf_target_defined >>> #else >>> >>> /* Fall back to what the compiler says */ >>> @@ -62,6 +65,9 @@ >>> #elif defined(__arc__) >>> #define bpf_target_arc >>> #define bpf_target_defined >>> +#elif defined(__loongarch__) && __loongarch_grlen == 64 >>> + #define bpf_target_loongarch >>> + #define bpf_target_defined >>> #endif /* no compiler target */ >>> >>> #endif >>> @@ -258,6 +264,21 @@ struct pt_regs___arm64 { >>> /* arc does not select ARCH_HAS_SYSCALL_WRAPPER. */ >>> #define PT_REGS_SYSCALL_REGS(ctx) ctx >>> >>> +#elif defined(bpf_target_loongarch) >>> + >>> +#define __PT_PARM1_REG regs[5] >>> +#define __PT_PARM2_REG regs[6] >>> +#define __PT_PARM3_REG regs[7] >>> +#define __PT_PARM4_REG regs[8] >>> +#define __PT_PARM5_REG regs[9] >>> +#define __PT_RET_REG regs[1] >>> +#define __PT_FP_REG regs[22] >>> +#define __PT_RC_REG regs[4] >>> +#define __PT_SP_REG regs[3] >>> +#define __PT_IP_REG csr_era >>> +/* loongarch does not select ARCH_HAS_SYSCALL_WRAPPER. */ >>> +#define PT_REGS_SYSCALL_REGS(ctx) ctx >> >> Is there some online documentation explaining this architecture's >> calling conventions? It would be useful to include that as a comment >> to be able to refer back to it. On a related note, are there any >> syscall specific calling convention differences, similar to >> PT_REGS_PARM1_SYSCALL for arm64 or PT_REGS_PARM4_SYSCALL for x86-64? >> > > Ok, I think [0] would be a good resource, please add a link to it in > the comment. But also it seems like PARM1-5 should map to regs[6] > through regs[10] (not regs[5] - regs[9] that you have here). And BTW, > seems like architecture supports passing more than five, PARM6 would > be regs[11]. I've been wanting to add 6th+ argument to libbpf macros' > for a while (it came up in x86-64 world for uprobes as well), so if > you have cycles, please consider helping with that as well. > I've seen this on GitHub. Let me have a try. > Also I see orig_a0 in struct pt_regs, which seems suspiciously similar > to arm64's PT_REGS_PARM1_SYSCALL's use of orig_x0, please check about > that as well. As I said, syscalls usually have some additional quirks. > > > [0] https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html > > >>> + >>> #endif >>> >>> #if defined(bpf_target_defined) >>> -- >>> 2.31.1 Thanks, Andrii. After some investigation, I do find some quirks on syscalls. Will update this patch.
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h index 2972dc25ff72..2d7da1caa961 100644 --- a/tools/lib/bpf/bpf_tracing.h +++ b/tools/lib/bpf/bpf_tracing.h @@ -32,6 +32,9 @@ #elif defined(__TARGET_ARCH_arc) #define bpf_target_arc #define bpf_target_defined +#elif defined(__TARGET_ARCH_loongarch) + #define bpf_target_loongarch + #define bpf_target_defined #else /* Fall back to what the compiler says */ @@ -62,6 +65,9 @@ #elif defined(__arc__) #define bpf_target_arc #define bpf_target_defined +#elif defined(__loongarch__) && __loongarch_grlen == 64 + #define bpf_target_loongarch + #define bpf_target_defined #endif /* no compiler target */ #endif @@ -258,6 +264,21 @@ struct pt_regs___arm64 { /* arc does not select ARCH_HAS_SYSCALL_WRAPPER. */ #define PT_REGS_SYSCALL_REGS(ctx) ctx +#elif defined(bpf_target_loongarch) + +#define __PT_PARM1_REG regs[5] +#define __PT_PARM2_REG regs[6] +#define __PT_PARM3_REG regs[7] +#define __PT_PARM4_REG regs[8] +#define __PT_PARM5_REG regs[9] +#define __PT_RET_REG regs[1] +#define __PT_FP_REG regs[22] +#define __PT_RC_REG regs[4] +#define __PT_SP_REG regs[3] +#define __PT_IP_REG csr_era +/* loongarch does not select ARCH_HAS_SYSCALL_WRAPPER. */ +#define PT_REGS_SYSCALL_REGS(ctx) ctx + #endif #if defined(bpf_target_defined)
Add PT_REGS macros for LoongArch64. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> --- tools/lib/bpf/bpf_tracing.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) -- 2.31.1