[DTrace-devel] [PATCH 02/12] cg: Dummy implementation for d_path()
Eugene Loh
eugene.loh at oracle.com
Fri Jan 5 20:56:12 UTC 2024
Reviewed-by: Eugene Loh <eugene.loh at oracle.com>
But why do the .r results files change fi_dirname to .? Why not to
<unknown>?
How about adding a @@nosort to tst.fds.d while we're at it? Not
strictly part of this patch, but this could be a convenient time to add it.
How about a more descriptive name than <unknown>? Say, <d_path not
implemented>? I can see someone thinking that's distasteful, so I won't
push that suggestion.
How about adding a comment to the commit message about the BPF d_path
helper function?
On 1/5/24 00:24, Kris Van Hees via DTrace-devel wrote:
> Hardwire d_path() to always return "<unknown>" pending an implementation
> that really works. This stub allows io and procfs translators to work.
> Tests that will have their expected output adjusted for this stub will
> FAIL when a real implementation is introduced, and should be adjusted at
> that time.
>
> Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
> ---
> libdtrace/dt_cg.c | 34 +++++++++++++++++++++++++++++-
> test/unittest/io/tst.fds.aarch64.r | 20 +++++++++---------
> test/unittest/io/tst.fds.d | 3 +--
> test/unittest/io/tst.fds.sparc64.r | 20 +++++++++---------
> test/unittest/io/tst.fds.x86_64.r | 20 +++++++++---------
> 5 files changed, 64 insertions(+), 33 deletions(-)
>
> diff --git a/libdtrace/dt_cg.c b/libdtrace/dt_cg.c
> index 4332954e..30b1da16 100644
> --- a/libdtrace/dt_cg.c
> +++ b/libdtrace/dt_cg.c
> @@ -6257,6 +6257,38 @@ dt_cg_subr_inet_ntop(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
> tnp->dn_tstring = NULL;
> }
>
> +static void
> +dt_cg_subr_d_path(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
> +{
> + dt_node_t *arg = dnp->dn_args;
> +
> + dt_cg_node(arg, dlp, drp);
> + dt_cg_check_ptr_arg(dlp, drp, arg, NULL);
> +
> + /* Allocate a temporary string for the result. */
> + dnp->dn_reg = dt_regset_alloc(drp);
> + if (dnp->dn_reg == -1)
> + longjmp(yypcb->pcb_jmpbuf, EDT_NOREG);
> + dt_cg_tstring_alloc(yypcb, dnp);
> + emit(dlp, BPF_LOAD(BPF_DW, dnp->dn_reg, BPF_REG_FP, DT_STK_DCTX));
> + emit(dlp, BPF_LOAD(BPF_DW, dnp->dn_reg, dnp->dn_reg, DCTX_MEM));
> + emit(dlp, BPF_ALU64_IMM(BPF_ADD, dnp->dn_reg, dnp->dn_tstring->dn_value));
> +
> + /*
> + * We do not have a real implementation yet, so throw away the result
> + * of evaluating the argument, and return a default value "<unknown>"
> + * in a temporary string.
> + *
> + * <unknown> is 3c 75 6e 6b 6e 6f 77 6e 3e 00
> + */
> + dt_regset_free(drp, arg->dn_reg);
> + dt_cg_tstring_free(yypcb, arg);
> +
> + emit(dlp, BPF_STORE_IMM(BPF_W, dnp->dn_reg, 0, 0x6b6e753c));
> + emit(dlp, BPF_STORE_IMM(BPF_W, dnp->dn_reg, 4, 0x6e776f6e));
> + emit(dlp, BPF_STORE_IMM(BPF_H, dnp->dn_reg, 8, 0x003e));
> +}
> +
> static void
> dt_cg_subr_link_ntop(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
> {
> @@ -6323,7 +6355,7 @@ static dt_cg_subr_f *_dt_cg_subr[DIF_SUBR_MAX + 1] = {
> [DIF_SUBR_INET_NTOP] = &dt_cg_subr_inet_ntop,
> [DIF_SUBR_INET_NTOA] = &dt_cg_subr_inet_ntoa,
> [DIF_SUBR_INET_NTOA6] = &dt_cg_subr_inet_ntoa6,
> - [DIF_SUBR_D_PATH] = NULL,
> + [DIF_SUBR_D_PATH] = &dt_cg_subr_d_path,
> [DIF_SUBR_LINK_NTOP] = &dt_cg_subr_link_ntop,
> };
>
> diff --git a/test/unittest/io/tst.fds.aarch64.r b/test/unittest/io/tst.fds.aarch64.r
> index e953785c..e1160e5d 100644
> --- a/test/unittest/io/tst.fds.aarch64.r
> +++ b/test/unittest/io/tst.fds.aarch64.r
> @@ -1,31 +1,31 @@
>
> -fds[0] fi_dirname = /proc/#
> +fds[0] fi_dirname = .
> fds[0] fi_mount = <unknown>
> fds[0] fi_name = mem
> fds[0] fi_offset = 0
> fds[0] fi_oflags = 20000
> -fds[0] fi_pathname = /proc/#/mem
> -fds[1] fi_dirname = /proc/#
> +fds[0] fi_pathname = <unknown>
> +fds[1] fi_dirname = .
> fds[1] fi_mount = <unknown>
> fds[1] fi_name = mem
> fds[1] fi_offset = 0
> fds[1] fi_oflags = 20001
> -fds[1] fi_pathname = /proc/#/mem
> -fds[2] fi_dirname = /proc/#
> +fds[1] fi_pathname = <unknown>
> +fds[2] fi_dirname = .
> fds[2] fi_mount = <unknown>
> fds[2] fi_name = mem
> fds[2] fi_offset = 0
> fds[2] fi_oflags = 20002
> -fds[2] fi_pathname = /proc/#/mem
> -fds[3] fi_dirname = /proc/#
> +fds[2] fi_pathname = <unknown>
> +fds[3] fi_dirname = .
> fds[3] fi_mount = <unknown>
> fds[3] fi_name = mem
> fds[3] fi_offset = 0
> fds[3] fi_oflags = 121c02
> -fds[3] fi_pathname = /proc/#/mem
> -fds[4] fi_dirname = /proc/#
> +fds[3] fi_pathname = <unknown>
> +fds[4] fi_dirname = .
> fds[4] fi_mount = <unknown>
> fds[4] fi_name = mem
> fds[4] fi_offset = 123
> fds[4] fi_oflags = 20002
> -fds[4] fi_pathname = /proc/#/mem
> +fds[4] fi_pathname = <unknown>
> diff --git a/test/unittest/io/tst.fds.d b/test/unittest/io/tst.fds.d
> index b762e6ac..06caefe4 100644
> --- a/test/unittest/io/tst.fds.d
> +++ b/test/unittest/io/tst.fds.d
> @@ -1,11 +1,10 @@
> /*
> * Oracle Linux DTrace.
> - * Copyright (c) 2006, 2020, Oracle and/or its affiliates. All rights reserved.
> + * Copyright (c) 2006, 2024, Oracle and/or its affiliates. All rights reserved.
> * Licensed under the Universal Permissive License v 1.0 as shown at
> * http://oss.oracle.com/licenses/upl.
> */
>
> -/* @@xfail: dtv2 */
> /* @@trigger: bogus-ioctl */
> /* @@trigger-timing: after */
> /* @@runtest-opts: -C $_pid */
> diff --git a/test/unittest/io/tst.fds.sparc64.r b/test/unittest/io/tst.fds.sparc64.r
> index d787a14b..71cc8309 100644
> --- a/test/unittest/io/tst.fds.sparc64.r
> +++ b/test/unittest/io/tst.fds.sparc64.r
> @@ -1,31 +1,31 @@
>
> -fds[0] fi_dirname = /proc/#
> +fds[0] fi_dirname = .
> fds[0] fi_mount = <unknown>
> fds[0] fi_name = mem
> fds[0] fi_offset = 0
> fds[0] fi_oflags = 40000
> -fds[0] fi_pathname = /proc/#/mem
> -fds[1] fi_dirname = /proc/#
> +fds[0] fi_pathname = <unknown>
> +fds[1] fi_dirname = .
> fds[1] fi_mount = <unknown>
> fds[1] fi_name = mem
> fds[1] fi_offset = 0
> fds[1] fi_oflags = 40001
> -fds[1] fi_pathname = /proc/#/mem
> -fds[2] fi_dirname = /proc/#
> +fds[1] fi_pathname = <unknown>
> +fds[2] fi_dirname = .
> fds[2] fi_mount = <unknown>
> fds[2] fi_name = mem
> fds[2] fi_offset = 0
> fds[2] fi_oflags = 40002
> -fds[2] fi_pathname = /proc/#/mem
> -fds[3] fi_dirname = /proc/#
> +fds[2] fi_pathname = <unknown>
> +fds[3] fi_dirname = .
> fds[3] fi_mount = <unknown>
> fds[3] fi_name = mem
> fds[3] fi_offset = 0
> fds[3] fi_oflags = 84600e
> -fds[3] fi_pathname = /proc/#/mem
> -fds[4] fi_dirname = /proc/#
> +fds[3] fi_pathname = <unknown>
> +fds[4] fi_dirname = .
> fds[4] fi_mount = <unknown>
> fds[4] fi_name = mem
> fds[4] fi_offset = 123
> fds[4] fi_oflags = 40002
> -fds[4] fi_pathname = /proc/#/mem
> +fds[4] fi_pathname = <unknown>
> diff --git a/test/unittest/io/tst.fds.x86_64.r b/test/unittest/io/tst.fds.x86_64.r
> index ec42330c..799e8562 100644
> --- a/test/unittest/io/tst.fds.x86_64.r
> +++ b/test/unittest/io/tst.fds.x86_64.r
> @@ -1,31 +1,31 @@
>
> -fds[0] fi_dirname = /proc/#
> +fds[0] fi_dirname = .
> fds[0] fi_mount = <unknown>
> fds[0] fi_name = mem
> fds[0] fi_offset = 0
> fds[0] fi_oflags = 8000
> -fds[0] fi_pathname = /proc/#/mem
> -fds[1] fi_dirname = /proc/#
> +fds[0] fi_pathname = <unknown>
> +fds[1] fi_dirname = .
> fds[1] fi_mount = <unknown>
> fds[1] fi_name = mem
> fds[1] fi_offset = 0
> fds[1] fi_oflags = 8001
> -fds[1] fi_pathname = /proc/#/mem
> -fds[2] fi_dirname = /proc/#
> +fds[1] fi_pathname = <unknown>
> +fds[2] fi_dirname = .
> fds[2] fi_mount = <unknown>
> fds[2] fi_name = mem
> fds[2] fi_offset = 0
> fds[2] fi_oflags = 8002
> -fds[2] fi_pathname = /proc/#/mem
> -fds[3] fi_dirname = /proc/#
> +fds[2] fi_pathname = <unknown>
> +fds[3] fi_dirname = .
> fds[3] fi_mount = <unknown>
> fds[3] fi_name = mem
> fds[3] fi_offset = 0
> fds[3] fi_oflags = 109c02
> -fds[3] fi_pathname = /proc/#/mem
> -fds[4] fi_dirname = /proc/#
> +fds[3] fi_pathname = <unknown>
> +fds[4] fi_dirname = .
> fds[4] fi_mount = <unknown>
> fds[4] fi_name = mem
> fds[4] fi_offset = 123
> fds[4] fi_oflags = 8002
> -fds[4] fi_pathname = /proc/#/mem
> +fds[4] fi_pathname = <unknown>
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