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* [PATCH bpf-next] libbpf: Support riscv USDT argument parsing logic
@ 2022-04-18  4:22 ` Pu Lehui
  0 siblings, 0 replies; 6+ messages in thread
From: Pu Lehui @ 2022-04-18  4:22 UTC (permalink / raw)
  To: bpf, linux-kernel, netdev, linux-riscv
  Cc: andrii, ast, daniel, kafai, songliubraving, yhs, john.fastabend,
	kpsingh, paul.walmsley, palmer, aou, pulehui

Add riscv-specific USDT argument specification parsing logic.
riscv USDT argument format is shown below:
- Memory dereference case:
  "size@off(reg)", e.g. "-8@-88(s0)"
- Constant value case:
  "size@val", e.g. "4@5"
- Register read case:
  "size@reg", e.g. "-8@a1"

s8 will be marked as poison while it's a reg of riscv, we need
to alias it in advance.

Signed-off-by: Pu Lehui <pulehui@huawei.com>
---
 tools/lib/bpf/usdt.c | 107 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)

diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c
index 934c25301ac1..b8af409cc763 100644
--- a/tools/lib/bpf/usdt.c
+++ b/tools/lib/bpf/usdt.c
@@ -10,6 +10,11 @@
 #include <linux/ptrace.h>
 #include <linux/kernel.h>
 
+/* s8 will be marked as poison while it's a reg of riscv */
+#if defined(__riscv)
+#define rv_s8 s8
+#endif
+
 #include "bpf.h"
 #include "libbpf.h"
 #include "libbpf_common.h"
@@ -1400,6 +1405,108 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec
 	return len;
 }
 
+#elif defined(__riscv)
+
+static int calc_pt_regs_off(const char *reg_name)
+{
+	static struct {
+		const char *name;
+		size_t pt_regs_off;
+	} reg_map[] = {
+		{ "ra", offsetof(struct user_regs_struct, ra) },
+		{ "sp", offsetof(struct user_regs_struct, sp) },
+		{ "gp", offsetof(struct user_regs_struct, gp) },
+		{ "tp", offsetof(struct user_regs_struct, tp) },
+		{ "t0", offsetof(struct user_regs_struct, t0) },
+		{ "t1", offsetof(struct user_regs_struct, t1) },
+		{ "t2", offsetof(struct user_regs_struct, t2) },
+		{ "s0", offsetof(struct user_regs_struct, s0) },
+		{ "s1", offsetof(struct user_regs_struct, s1) },
+		{ "a0", offsetof(struct user_regs_struct, a0) },
+		{ "a1", offsetof(struct user_regs_struct, a1) },
+		{ "a2", offsetof(struct user_regs_struct, a2) },
+		{ "a3", offsetof(struct user_regs_struct, a3) },
+		{ "a4", offsetof(struct user_regs_struct, a4) },
+		{ "a5", offsetof(struct user_regs_struct, a5) },
+		{ "a6", offsetof(struct user_regs_struct, a6) },
+		{ "a7", offsetof(struct user_regs_struct, a7) },
+		{ "s2", offsetof(struct user_regs_struct, s2) },
+		{ "s3", offsetof(struct user_regs_struct, s3) },
+		{ "s4", offsetof(struct user_regs_struct, s4) },
+		{ "s5", offsetof(struct user_regs_struct, s5) },
+		{ "s6", offsetof(struct user_regs_struct, s6) },
+		{ "s7", offsetof(struct user_regs_struct, s7) },
+		{ "s8", offsetof(struct user_regs_struct, rv_s8) },
+		{ "s9", offsetof(struct user_regs_struct, s9) },
+		{ "s10", offsetof(struct user_regs_struct, s10) },
+		{ "s11", offsetof(struct user_regs_struct, s11) },
+		{ "t3", offsetof(struct user_regs_struct, t3) },
+		{ "t4", offsetof(struct user_regs_struct, t4) },
+		{ "t5", offsetof(struct user_regs_struct, t5) },
+		{ "t6", offsetof(struct user_regs_struct, t6) },
+	};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(reg_map); i++) {
+		if (strcmp(reg_name, reg_map[i].name) == 0)
+			return reg_map[i].pt_regs_off;
+	}
+
+	pr_warn("usdt: unrecognized register '%s'\n", reg_name);
+	return -ENOENT;
+}
+
+static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg)
+{
+	char *reg_name = NULL;
+	int arg_sz, len, reg_off;
+	long off;
+
+	if (sscanf(arg_str, " %d @ %ld ( %m[a-z0-9] ) %n", &arg_sz, &off, &reg_name, &len) == 3) {
+		/* Memory dereference case, e.g., -8@-88(s0) */
+		arg->arg_type = USDT_ARG_REG_DEREF;
+		arg->val_off = off;
+		reg_off = calc_pt_regs_off(reg_name);
+		free(reg_name);
+		if (reg_off < 0)
+			return reg_off;
+		arg->reg_off = reg_off;
+	} else if (sscanf(arg_str, " %d @ %ld %n", &arg_sz, &off, &len) == 2) {
+		/* Constant value case, e.g., 4@5 */
+		arg->arg_type = USDT_ARG_CONST;
+		arg->val_off = off;
+		arg->reg_off = 0;
+	} else if (sscanf(arg_str, " %d @ %m[a-z0-9] %n", &arg_sz, &reg_name, &len) == 2) {
+		/* Register read case, e.g., -8@a1 */
+		arg->arg_type = USDT_ARG_REG;
+		arg->val_off = 0;
+		reg_off = calc_pt_regs_off(reg_name);
+		free(reg_name);
+		if (reg_off < 0)
+			return reg_off;
+		arg->reg_off = reg_off;
+	} else {
+		pr_warn("usdt: unrecognized arg #%d spec '%s'\n", arg_num, arg_str);
+		return -EINVAL;
+	}
+
+	arg->arg_signed = arg_sz < 0;
+	if (arg_sz < 0)
+		arg_sz = -arg_sz;
+
+	switch (arg_sz) {
+	case 1: case 2: case 4: case 8:
+		arg->arg_bitshift = 64 - arg_sz * 8;
+		break;
+	default:
+		pr_warn("usdt: unsupported arg #%d (spec '%s') size: %d\n",
+			arg_num, arg_str, arg_sz);
+		return -EINVAL;
+	}
+
+	return len;
+}
+
 #else
 
 static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg)
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH bpf-next] libbpf: Support riscv USDT argument parsing logic
@ 2022-04-18  4:22 ` Pu Lehui
  0 siblings, 0 replies; 6+ messages in thread
From: Pu Lehui @ 2022-04-18  4:22 UTC (permalink / raw)
  To: bpf, linux-kernel, netdev, linux-riscv
  Cc: andrii, ast, daniel, kafai, songliubraving, yhs, john.fastabend,
	kpsingh, paul.walmsley, palmer, aou, pulehui

Add riscv-specific USDT argument specification parsing logic.
riscv USDT argument format is shown below:
- Memory dereference case:
  "size@off(reg)", e.g. "-8@-88(s0)"
- Constant value case:
  "size@val", e.g. "4@5"
- Register read case:
  "size@reg", e.g. "-8@a1"

s8 will be marked as poison while it's a reg of riscv, we need
to alias it in advance.

Signed-off-by: Pu Lehui <pulehui@huawei.com>
---
 tools/lib/bpf/usdt.c | 107 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)

diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c
index 934c25301ac1..b8af409cc763 100644
--- a/tools/lib/bpf/usdt.c
+++ b/tools/lib/bpf/usdt.c
@@ -10,6 +10,11 @@
 #include <linux/ptrace.h>
 #include <linux/kernel.h>
 
+/* s8 will be marked as poison while it's a reg of riscv */
+#if defined(__riscv)
+#define rv_s8 s8
+#endif
+
 #include "bpf.h"
 #include "libbpf.h"
 #include "libbpf_common.h"
@@ -1400,6 +1405,108 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec
 	return len;
 }
 
+#elif defined(__riscv)
+
+static int calc_pt_regs_off(const char *reg_name)
+{
+	static struct {
+		const char *name;
+		size_t pt_regs_off;
+	} reg_map[] = {
+		{ "ra", offsetof(struct user_regs_struct, ra) },
+		{ "sp", offsetof(struct user_regs_struct, sp) },
+		{ "gp", offsetof(struct user_regs_struct, gp) },
+		{ "tp", offsetof(struct user_regs_struct, tp) },
+		{ "t0", offsetof(struct user_regs_struct, t0) },
+		{ "t1", offsetof(struct user_regs_struct, t1) },
+		{ "t2", offsetof(struct user_regs_struct, t2) },
+		{ "s0", offsetof(struct user_regs_struct, s0) },
+		{ "s1", offsetof(struct user_regs_struct, s1) },
+		{ "a0", offsetof(struct user_regs_struct, a0) },
+		{ "a1", offsetof(struct user_regs_struct, a1) },
+		{ "a2", offsetof(struct user_regs_struct, a2) },
+		{ "a3", offsetof(struct user_regs_struct, a3) },
+		{ "a4", offsetof(struct user_regs_struct, a4) },
+		{ "a5", offsetof(struct user_regs_struct, a5) },
+		{ "a6", offsetof(struct user_regs_struct, a6) },
+		{ "a7", offsetof(struct user_regs_struct, a7) },
+		{ "s2", offsetof(struct user_regs_struct, s2) },
+		{ "s3", offsetof(struct user_regs_struct, s3) },
+		{ "s4", offsetof(struct user_regs_struct, s4) },
+		{ "s5", offsetof(struct user_regs_struct, s5) },
+		{ "s6", offsetof(struct user_regs_struct, s6) },
+		{ "s7", offsetof(struct user_regs_struct, s7) },
+		{ "s8", offsetof(struct user_regs_struct, rv_s8) },
+		{ "s9", offsetof(struct user_regs_struct, s9) },
+		{ "s10", offsetof(struct user_regs_struct, s10) },
+		{ "s11", offsetof(struct user_regs_struct, s11) },
+		{ "t3", offsetof(struct user_regs_struct, t3) },
+		{ "t4", offsetof(struct user_regs_struct, t4) },
+		{ "t5", offsetof(struct user_regs_struct, t5) },
+		{ "t6", offsetof(struct user_regs_struct, t6) },
+	};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(reg_map); i++) {
+		if (strcmp(reg_name, reg_map[i].name) == 0)
+			return reg_map[i].pt_regs_off;
+	}
+
+	pr_warn("usdt: unrecognized register '%s'\n", reg_name);
+	return -ENOENT;
+}
+
+static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg)
+{
+	char *reg_name = NULL;
+	int arg_sz, len, reg_off;
+	long off;
+
+	if (sscanf(arg_str, " %d @ %ld ( %m[a-z0-9] ) %n", &arg_sz, &off, &reg_name, &len) == 3) {
+		/* Memory dereference case, e.g., -8@-88(s0) */
+		arg->arg_type = USDT_ARG_REG_DEREF;
+		arg->val_off = off;
+		reg_off = calc_pt_regs_off(reg_name);
+		free(reg_name);
+		if (reg_off < 0)
+			return reg_off;
+		arg->reg_off = reg_off;
+	} else if (sscanf(arg_str, " %d @ %ld %n", &arg_sz, &off, &len) == 2) {
+		/* Constant value case, e.g., 4@5 */
+		arg->arg_type = USDT_ARG_CONST;
+		arg->val_off = off;
+		arg->reg_off = 0;
+	} else if (sscanf(arg_str, " %d @ %m[a-z0-9] %n", &arg_sz, &reg_name, &len) == 2) {
+		/* Register read case, e.g., -8@a1 */
+		arg->arg_type = USDT_ARG_REG;
+		arg->val_off = 0;
+		reg_off = calc_pt_regs_off(reg_name);
+		free(reg_name);
+		if (reg_off < 0)
+			return reg_off;
+		arg->reg_off = reg_off;
+	} else {
+		pr_warn("usdt: unrecognized arg #%d spec '%s'\n", arg_num, arg_str);
+		return -EINVAL;
+	}
+
+	arg->arg_signed = arg_sz < 0;
+	if (arg_sz < 0)
+		arg_sz = -arg_sz;
+
+	switch (arg_sz) {
+	case 1: case 2: case 4: case 8:
+		arg->arg_bitshift = 64 - arg_sz * 8;
+		break;
+	default:
+		pr_warn("usdt: unsupported arg #%d (spec '%s') size: %d\n",
+			arg_num, arg_str, arg_sz);
+		return -EINVAL;
+	}
+
+	return len;
+}
+
 #else
 
 static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg)
-- 
2.25.1


_______________________________________________
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next] libbpf: Support riscv USDT argument parsing logic
  2022-04-18  4:22 ` Pu Lehui
@ 2022-04-19  4:33   ` Andrii Nakryiko
  -1 siblings, 0 replies; 6+ messages in thread
From: Andrii Nakryiko @ 2022-04-19  4:33 UTC (permalink / raw)
  To: Pu Lehui
  Cc: bpf, open list, Networking, linux-riscv, Andrii Nakryiko,
	Alexei Starovoitov, Daniel Borkmann, Martin Lau, Song Liu,
	Yonghong Song, john fastabend, KP Singh, Paul Walmsley,
	Palmer Dabbelt, Albert Ou

On Sun, Apr 17, 2022 at 8:53 PM Pu Lehui <pulehui@huawei.com> wrote:
>
> Add riscv-specific USDT argument specification parsing logic.
> riscv USDT argument format is shown below:
> - Memory dereference case:
>   "size@off(reg)", e.g. "-8@-88(s0)"
> - Constant value case:
>   "size@val", e.g. "4@5"
> - Register read case:
>   "size@reg", e.g. "-8@a1"
>
> s8 will be marked as poison while it's a reg of riscv, we need
> to alias it in advance.
>
> Signed-off-by: Pu Lehui <pulehui@huawei.com>
> ---

Can you please mention briefly the testing you performed as I'm not
able to test this locally.

>  tools/lib/bpf/usdt.c | 107 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 107 insertions(+)
>
> diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c
> index 934c25301ac1..b8af409cc763 100644
> --- a/tools/lib/bpf/usdt.c
> +++ b/tools/lib/bpf/usdt.c
> @@ -10,6 +10,11 @@
>  #include <linux/ptrace.h>
>  #include <linux/kernel.h>
>
> +/* s8 will be marked as poison while it's a reg of riscv */
> +#if defined(__riscv)
> +#define rv_s8 s8
> +#endif
> +
>  #include "bpf.h"
>  #include "libbpf.h"
>  #include "libbpf_common.h"
> @@ -1400,6 +1405,108 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec
>         return len;
>  }
>
> +#elif defined(__riscv)
> +
> +static int calc_pt_regs_off(const char *reg_name)
> +{
> +       static struct {
> +               const char *name;
> +               size_t pt_regs_off;
> +       } reg_map[] = {
> +               { "ra", offsetof(struct user_regs_struct, ra) },
> +               { "sp", offsetof(struct user_regs_struct, sp) },
> +               { "gp", offsetof(struct user_regs_struct, gp) },
> +               { "tp", offsetof(struct user_regs_struct, tp) },
> +               { "t0", offsetof(struct user_regs_struct, t0) },
> +               { "t1", offsetof(struct user_regs_struct, t1) },
> +               { "t2", offsetof(struct user_regs_struct, t2) },
> +               { "s0", offsetof(struct user_regs_struct, s0) },
> +               { "s1", offsetof(struct user_regs_struct, s1) },
> +               { "a0", offsetof(struct user_regs_struct, a0) },
> +               { "a1", offsetof(struct user_regs_struct, a1) },
> +               { "a2", offsetof(struct user_regs_struct, a2) },
> +               { "a3", offsetof(struct user_regs_struct, a3) },
> +               { "a4", offsetof(struct user_regs_struct, a4) },
> +               { "a5", offsetof(struct user_regs_struct, a5) },
> +               { "a6", offsetof(struct user_regs_struct, a6) },
> +               { "a7", offsetof(struct user_regs_struct, a7) },
> +               { "s2", offsetof(struct user_regs_struct, s2) },
> +               { "s3", offsetof(struct user_regs_struct, s3) },
> +               { "s4", offsetof(struct user_regs_struct, s4) },
> +               { "s5", offsetof(struct user_regs_struct, s5) },
> +               { "s6", offsetof(struct user_regs_struct, s6) },
> +               { "s7", offsetof(struct user_regs_struct, s7) },
> +               { "s8", offsetof(struct user_regs_struct, rv_s8) },
> +               { "s9", offsetof(struct user_regs_struct, s9) },
> +               { "s10", offsetof(struct user_regs_struct, s10) },
> +               { "s11", offsetof(struct user_regs_struct, s11) },
> +               { "t3", offsetof(struct user_regs_struct, t3) },
> +               { "t4", offsetof(struct user_regs_struct, t4) },
> +               { "t5", offsetof(struct user_regs_struct, t5) },
> +               { "t6", offsetof(struct user_regs_struct, t6) },

would it make sense to order registers a bit more "logically"? Like
s0-s11, t0-t6, etc. Right now it looks very random and it's hard to
see if all the registers from some range of registers are defined.

> +       };
> +       int i;
> +

[...]

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next] libbpf: Support riscv USDT argument parsing logic
@ 2022-04-19  4:33   ` Andrii Nakryiko
  0 siblings, 0 replies; 6+ messages in thread
From: Andrii Nakryiko @ 2022-04-19  4:33 UTC (permalink / raw)
  To: Pu Lehui
  Cc: bpf, open list, Networking, linux-riscv, Andrii Nakryiko,
	Alexei Starovoitov, Daniel Borkmann, Martin Lau, Song Liu,
	Yonghong Song, john fastabend, KP Singh, Paul Walmsley,
	Palmer Dabbelt, Albert Ou

On Sun, Apr 17, 2022 at 8:53 PM Pu Lehui <pulehui@huawei.com> wrote:
>
> Add riscv-specific USDT argument specification parsing logic.
> riscv USDT argument format is shown below:
> - Memory dereference case:
>   "size@off(reg)", e.g. "-8@-88(s0)"
> - Constant value case:
>   "size@val", e.g. "4@5"
> - Register read case:
>   "size@reg", e.g. "-8@a1"
>
> s8 will be marked as poison while it's a reg of riscv, we need
> to alias it in advance.
>
> Signed-off-by: Pu Lehui <pulehui@huawei.com>
> ---

Can you please mention briefly the testing you performed as I'm not
able to test this locally.

>  tools/lib/bpf/usdt.c | 107 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 107 insertions(+)
>
> diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c
> index 934c25301ac1..b8af409cc763 100644
> --- a/tools/lib/bpf/usdt.c
> +++ b/tools/lib/bpf/usdt.c
> @@ -10,6 +10,11 @@
>  #include <linux/ptrace.h>
>  #include <linux/kernel.h>
>
> +/* s8 will be marked as poison while it's a reg of riscv */
> +#if defined(__riscv)
> +#define rv_s8 s8
> +#endif
> +
>  #include "bpf.h"
>  #include "libbpf.h"
>  #include "libbpf_common.h"
> @@ -1400,6 +1405,108 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec
>         return len;
>  }
>
> +#elif defined(__riscv)
> +
> +static int calc_pt_regs_off(const char *reg_name)
> +{
> +       static struct {
> +               const char *name;
> +               size_t pt_regs_off;
> +       } reg_map[] = {
> +               { "ra", offsetof(struct user_regs_struct, ra) },
> +               { "sp", offsetof(struct user_regs_struct, sp) },
> +               { "gp", offsetof(struct user_regs_struct, gp) },
> +               { "tp", offsetof(struct user_regs_struct, tp) },
> +               { "t0", offsetof(struct user_regs_struct, t0) },
> +               { "t1", offsetof(struct user_regs_struct, t1) },
> +               { "t2", offsetof(struct user_regs_struct, t2) },
> +               { "s0", offsetof(struct user_regs_struct, s0) },
> +               { "s1", offsetof(struct user_regs_struct, s1) },
> +               { "a0", offsetof(struct user_regs_struct, a0) },
> +               { "a1", offsetof(struct user_regs_struct, a1) },
> +               { "a2", offsetof(struct user_regs_struct, a2) },
> +               { "a3", offsetof(struct user_regs_struct, a3) },
> +               { "a4", offsetof(struct user_regs_struct, a4) },
> +               { "a5", offsetof(struct user_regs_struct, a5) },
> +               { "a6", offsetof(struct user_regs_struct, a6) },
> +               { "a7", offsetof(struct user_regs_struct, a7) },
> +               { "s2", offsetof(struct user_regs_struct, s2) },
> +               { "s3", offsetof(struct user_regs_struct, s3) },
> +               { "s4", offsetof(struct user_regs_struct, s4) },
> +               { "s5", offsetof(struct user_regs_struct, s5) },
> +               { "s6", offsetof(struct user_regs_struct, s6) },
> +               { "s7", offsetof(struct user_regs_struct, s7) },
> +               { "s8", offsetof(struct user_regs_struct, rv_s8) },
> +               { "s9", offsetof(struct user_regs_struct, s9) },
> +               { "s10", offsetof(struct user_regs_struct, s10) },
> +               { "s11", offsetof(struct user_regs_struct, s11) },
> +               { "t3", offsetof(struct user_regs_struct, t3) },
> +               { "t4", offsetof(struct user_regs_struct, t4) },
> +               { "t5", offsetof(struct user_regs_struct, t5) },
> +               { "t6", offsetof(struct user_regs_struct, t6) },

would it make sense to order registers a bit more "logically"? Like
s0-s11, t0-t6, etc. Right now it looks very random and it's hard to
see if all the registers from some range of registers are defined.

> +       };
> +       int i;
> +

[...]

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^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next] libbpf: Support riscv USDT argument parsing logic
  2022-04-19  4:33   ` Andrii Nakryiko
@ 2022-04-19 13:00     ` Pu Lehui
  -1 siblings, 0 replies; 6+ messages in thread
From: Pu Lehui @ 2022-04-19 13:00 UTC (permalink / raw)
  To: Andrii Nakryiko
  Cc: bpf, open list, Networking, linux-riscv, Andrii Nakryiko,
	Alexei Starovoitov, Daniel Borkmann, Martin Lau, Song Liu,
	Yonghong Song, john fastabend, KP Singh, Paul Walmsley,
	Palmer Dabbelt, Albert Ou



On 2022/4/19 12:33, Andrii Nakryiko wrote:
> On Sun, Apr 17, 2022 at 8:53 PM Pu Lehui <pulehui@huawei.com> wrote:
>>
>> Add riscv-specific USDT argument specification parsing logic.
>> riscv USDT argument format is shown below:
>> - Memory dereference case:
>>    "size@off(reg)", e.g. "-8@-88(s0)"
>> - Constant value case:
>>    "size@val", e.g. "4@5"
>> - Register read case:
>>    "size@reg", e.g. "-8@a1"
>>
>> s8 will be marked as poison while it's a reg of riscv, we need
>> to alias it in advance.
>>
>> Signed-off-by: Pu Lehui <pulehui@huawei.com>
>> ---
> 
> Can you please mention briefly the testing you performed as I'm not
> able to test this locally.
> 
Both RV32 and RV64 have been tested. I will attach the test result in 
v2. Meanwhile, I found a small problem with libbpf USDT, and will be 
post in v2.
>>   tools/lib/bpf/usdt.c | 107 +++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 107 insertions(+)
>>
>> diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c
>> index 934c25301ac1..b8af409cc763 100644
>> --- a/tools/lib/bpf/usdt.c
>> +++ b/tools/lib/bpf/usdt.c
>> @@ -10,6 +10,11 @@
>>   #include <linux/ptrace.h>
>>   #include <linux/kernel.h>
>>
>> +/* s8 will be marked as poison while it's a reg of riscv */
>> +#if defined(__riscv)
>> +#define rv_s8 s8
>> +#endif
>> +
>>   #include "bpf.h"
>>   #include "libbpf.h"
>>   #include "libbpf_common.h"
>> @@ -1400,6 +1405,108 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec
>>          return len;
>>   }
>>
>> +#elif defined(__riscv)
>> +
>> +static int calc_pt_regs_off(const char *reg_name)
>> +{
>> +       static struct {
>> +               const char *name;
>> +               size_t pt_regs_off;
>> +       } reg_map[] = {
>> +               { "ra", offsetof(struct user_regs_struct, ra) },
>> +               { "sp", offsetof(struct user_regs_struct, sp) },
>> +               { "gp", offsetof(struct user_regs_struct, gp) },
>> +               { "tp", offsetof(struct user_regs_struct, tp) },
>> +               { "t0", offsetof(struct user_regs_struct, t0) },
>> +               { "t1", offsetof(struct user_regs_struct, t1) },
>> +               { "t2", offsetof(struct user_regs_struct, t2) },
>> +               { "s0", offsetof(struct user_regs_struct, s0) },
>> +               { "s1", offsetof(struct user_regs_struct, s1) },
>> +               { "a0", offsetof(struct user_regs_struct, a0) },
>> +               { "a1", offsetof(struct user_regs_struct, a1) },
>> +               { "a2", offsetof(struct user_regs_struct, a2) },
>> +               { "a3", offsetof(struct user_regs_struct, a3) },
>> +               { "a4", offsetof(struct user_regs_struct, a4) },
>> +               { "a5", offsetof(struct user_regs_struct, a5) },
>> +               { "a6", offsetof(struct user_regs_struct, a6) },
>> +               { "a7", offsetof(struct user_regs_struct, a7) },
>> +               { "s2", offsetof(struct user_regs_struct, s2) },
>> +               { "s3", offsetof(struct user_regs_struct, s3) },
>> +               { "s4", offsetof(struct user_regs_struct, s4) },
>> +               { "s5", offsetof(struct user_regs_struct, s5) },
>> +               { "s6", offsetof(struct user_regs_struct, s6) },
>> +               { "s7", offsetof(struct user_regs_struct, s7) },
>> +               { "s8", offsetof(struct user_regs_struct, rv_s8) },
>> +               { "s9", offsetof(struct user_regs_struct, s9) },
>> +               { "s10", offsetof(struct user_regs_struct, s10) },
>> +               { "s11", offsetof(struct user_regs_struct, s11) },
>> +               { "t3", offsetof(struct user_regs_struct, t3) },
>> +               { "t4", offsetof(struct user_regs_struct, t4) },
>> +               { "t5", offsetof(struct user_regs_struct, t5) },
>> +               { "t6", offsetof(struct user_regs_struct, t6) },
> 
> would it make sense to order registers a bit more "logically"? Like
> s0-s11, t0-t6, etc. Right now it looks very random and it's hard to
> see if all the registers from some range of registers are defined.
> 
I code it according to the RISCV specification, and for sure, we can 
make it more intuitive.

Thanks,
Lehui
>> +       };
>> +       int i;
>> +
> 
> [...]
> .
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next] libbpf: Support riscv USDT argument parsing logic
@ 2022-04-19 13:00     ` Pu Lehui
  0 siblings, 0 replies; 6+ messages in thread
From: Pu Lehui @ 2022-04-19 13:00 UTC (permalink / raw)
  To: Andrii Nakryiko
  Cc: bpf, open list, Networking, linux-riscv, Andrii Nakryiko,
	Alexei Starovoitov, Daniel Borkmann, Martin Lau, Song Liu,
	Yonghong Song, john fastabend, KP Singh, Paul Walmsley,
	Palmer Dabbelt, Albert Ou



On 2022/4/19 12:33, Andrii Nakryiko wrote:
> On Sun, Apr 17, 2022 at 8:53 PM Pu Lehui <pulehui@huawei.com> wrote:
>>
>> Add riscv-specific USDT argument specification parsing logic.
>> riscv USDT argument format is shown below:
>> - Memory dereference case:
>>    "size@off(reg)", e.g. "-8@-88(s0)"
>> - Constant value case:
>>    "size@val", e.g. "4@5"
>> - Register read case:
>>    "size@reg", e.g. "-8@a1"
>>
>> s8 will be marked as poison while it's a reg of riscv, we need
>> to alias it in advance.
>>
>> Signed-off-by: Pu Lehui <pulehui@huawei.com>
>> ---
> 
> Can you please mention briefly the testing you performed as I'm not
> able to test this locally.
> 
Both RV32 and RV64 have been tested. I will attach the test result in 
v2. Meanwhile, I found a small problem with libbpf USDT, and will be 
post in v2.
>>   tools/lib/bpf/usdt.c | 107 +++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 107 insertions(+)
>>
>> diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c
>> index 934c25301ac1..b8af409cc763 100644
>> --- a/tools/lib/bpf/usdt.c
>> +++ b/tools/lib/bpf/usdt.c
>> @@ -10,6 +10,11 @@
>>   #include <linux/ptrace.h>
>>   #include <linux/kernel.h>
>>
>> +/* s8 will be marked as poison while it's a reg of riscv */
>> +#if defined(__riscv)
>> +#define rv_s8 s8
>> +#endif
>> +
>>   #include "bpf.h"
>>   #include "libbpf.h"
>>   #include "libbpf_common.h"
>> @@ -1400,6 +1405,108 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec
>>          return len;
>>   }
>>
>> +#elif defined(__riscv)
>> +
>> +static int calc_pt_regs_off(const char *reg_name)
>> +{
>> +       static struct {
>> +               const char *name;
>> +               size_t pt_regs_off;
>> +       } reg_map[] = {
>> +               { "ra", offsetof(struct user_regs_struct, ra) },
>> +               { "sp", offsetof(struct user_regs_struct, sp) },
>> +               { "gp", offsetof(struct user_regs_struct, gp) },
>> +               { "tp", offsetof(struct user_regs_struct, tp) },
>> +               { "t0", offsetof(struct user_regs_struct, t0) },
>> +               { "t1", offsetof(struct user_regs_struct, t1) },
>> +               { "t2", offsetof(struct user_regs_struct, t2) },
>> +               { "s0", offsetof(struct user_regs_struct, s0) },
>> +               { "s1", offsetof(struct user_regs_struct, s1) },
>> +               { "a0", offsetof(struct user_regs_struct, a0) },
>> +               { "a1", offsetof(struct user_regs_struct, a1) },
>> +               { "a2", offsetof(struct user_regs_struct, a2) },
>> +               { "a3", offsetof(struct user_regs_struct, a3) },
>> +               { "a4", offsetof(struct user_regs_struct, a4) },
>> +               { "a5", offsetof(struct user_regs_struct, a5) },
>> +               { "a6", offsetof(struct user_regs_struct, a6) },
>> +               { "a7", offsetof(struct user_regs_struct, a7) },
>> +               { "s2", offsetof(struct user_regs_struct, s2) },
>> +               { "s3", offsetof(struct user_regs_struct, s3) },
>> +               { "s4", offsetof(struct user_regs_struct, s4) },
>> +               { "s5", offsetof(struct user_regs_struct, s5) },
>> +               { "s6", offsetof(struct user_regs_struct, s6) },
>> +               { "s7", offsetof(struct user_regs_struct, s7) },
>> +               { "s8", offsetof(struct user_regs_struct, rv_s8) },
>> +               { "s9", offsetof(struct user_regs_struct, s9) },
>> +               { "s10", offsetof(struct user_regs_struct, s10) },
>> +               { "s11", offsetof(struct user_regs_struct, s11) },
>> +               { "t3", offsetof(struct user_regs_struct, t3) },
>> +               { "t4", offsetof(struct user_regs_struct, t4) },
>> +               { "t5", offsetof(struct user_regs_struct, t5) },
>> +               { "t6", offsetof(struct user_regs_struct, t6) },
> 
> would it make sense to order registers a bit more "logically"? Like
> s0-s11, t0-t6, etc. Right now it looks very random and it's hard to
> see if all the registers from some range of registers are defined.
> 
I code it according to the RISCV specification, and for sure, we can 
make it more intuitive.

Thanks,
Lehui
>> +       };
>> +       int i;
>> +
> 
> [...]
> .
> 

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-04-19 13:48 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-04-18  4:22 [PATCH bpf-next] libbpf: Support riscv USDT argument parsing logic Pu Lehui
2022-04-18  4:22 ` Pu Lehui
2022-04-19  4:33 ` Andrii Nakryiko
2022-04-19  4:33   ` Andrii Nakryiko
2022-04-19 13:00   ` Pu Lehui
2022-04-19 13:00     ` Pu Lehui

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