From 029a3f8f523ea03f7a27ffba364a16b057cf970c Mon Sep 17 00:00:00 2001
From: Marc Hartmayer <mhartmay@linux.ibm.com>
Date: Wed, 5 Oct 2022 07:09:32 +0000
Subject: [PATCH] zdump: add guarded storage support for ELF input and output
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Add guarded storage registers support for the ELF input and the ELF output
format. See `man 2 s390_guarded_storage` for details about guarded storage.

Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
---
 zdump/df_elf.c  |  6 ++++++
 zdump/df_elf.h  | 12 ++++++++++++
 zdump/dfi.h     | 12 +++++++++++-
 zdump/dfi_elf.c | 14 ++++++++++++++
 zdump/dfo_elf.c |  2 ++
 5 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/zdump/df_elf.c b/zdump/df_elf.c
index 85788ac6..69c51e3c 100644
--- a/zdump/df_elf.c
+++ b/zdump/df_elf.c
@@ -310,6 +310,11 @@ void *nt_s390_vxrs_high(void *ptr, const struct dfi_cpu *cpu)
 		       sizeof(cpu->vxrs_high), NOTE_NAME_LINUX);
 }
 
+void *nt_s390_gs_cb(void *ptr, const struct dfi_cpu *cpu)
+{
+	return nt_init(ptr, NT_S390_GS_CB, &cpu->gscb, sizeof(cpu->gscb), NOTE_NAME_LINUX);
+}
+
 void *nt_prpsinfo(void *ptr)
 {
 	struct nt_prpsinfo_64 prpsinfo;
@@ -346,6 +351,7 @@ size_t get_max_note_size_per_cpu(void)
 	size += ELF64_NOTE_SIZE(NOTE_NAME_LINUX, sizeof_field(struct dfi_cpu, prefix));
 	size += ELF64_NOTE_SIZE(NOTE_NAME_LINUX, sizeof_field(struct dfi_cpu, vxrs_low));
 	size += ELF64_NOTE_SIZE(NOTE_NAME_LINUX, sizeof_field(struct dfi_cpu, vxrs_high));
+	size += ELF64_NOTE_SIZE(NOTE_NAME_LINUX, sizeof_field(struct dfi_cpu, gscb));
 
 	return size;
 }
diff --git a/zdump/df_elf.h b/zdump/df_elf.h
index 40b535ef..2a81fdea 100644
--- a/zdump/df_elf.h
+++ b/zdump/df_elf.h
@@ -74,6 +74,13 @@
 #define NT_S390_VXRS_HIGH 0x30a
 #endif
 
+/*
+ * S390 guarded-storage registers note (4 * u64)
+ */
+#ifndef NT_S390_GS_CB
+#define NT_S390_GS_CB 0x30b
+#endif
+
 #define NOTE_NAME_CORE	     "CORE"
 #define NOTE_NAME_LINUX	     "LINUX"
 #define NOTE_NAME_VMCOREINFO "VMCOREINFO"
@@ -259,6 +266,11 @@ void *nt_s390_vxrs_low(void *ptr, const struct dfi_cpu *cpu);
  */
 void *nt_s390_vxrs_high(void *ptr, const struct dfi_cpu *cpu);
 
+/*
+ * Initialize guarded-storage registers note
+ */
+void *nt_s390_gs_cb(void *ptr, const struct dfi_cpu *cpu);
+
 /*
  * Initialize prpsinfo note
  */
diff --git a/zdump/dfi.h b/zdump/dfi.h
index 42e51ecd..aa8f6dd9 100644
--- a/zdump/dfi.h
+++ b/zdump/dfi.h
@@ -99,6 +99,15 @@ struct dfi_cpu {
 	u32		todpreg;
 	u64		vxrs_low[16];
 	struct dfi_vxrs	vxrs_high[16];
+	union {
+		u64	gscb[4];
+		struct {
+			u64 reserved;
+			u64 gsd;
+			u64 gssm;
+			u64 gs_epl_a;
+		};
+	};
 	u16		cpu_id;
 };
 
@@ -127,7 +136,8 @@ enum dfi_cpu_content {
 	DFI_CPU_CONTENT_ALL,	/* Complete register information available */
 };
 
-#define DFI_CPU_CONTENT_FAC_VX	0x00000001
+#define DFI_CPU_CONTENT_FAC_VX 0x00000001
+#define DFI_CPU_CONTENT_FAC_GS 0x00000002
 int dfi_cpu_content_fac_check(int flags);
 void dfi_cpu_content_fac_add(int flags);
 
diff --git a/zdump/dfi_elf.c b/zdump/dfi_elf.c
index 605904bc..93e46f90 100644
--- a/zdump/dfi_elf.c
+++ b/zdump/dfi_elf.c
@@ -185,6 +185,15 @@ static int nt_s390_vxrs_high_read(const struct zg_fh *fh, struct dfi_cpu *cpu,
 	return nt_read(fh, note, &cpu->vxrs_high, sizeof(cpu->vxrs_high));
 }
 
+/*
+ * Read s390 gs_cb note
+ */
+static int nt_s390_gs_cb_read(const struct zg_fh *fh, struct dfi_cpu *cpu, const Elf64_Nhdr *note)
+{
+	check_cpu(cpu, "S390_GSCB");
+	return nt_read(fh, note, &cpu->gscb, sizeof(cpu->gscb));
+}
+
 /*
  * Add all notes for notes phdr
  */
@@ -243,6 +252,11 @@ static int pt_notes_add(const Elf64_Phdr *phdr)
 				return -EINVAL;
 			dfi_cpu_content_fac_add(DFI_CPU_CONTENT_FAC_VX);
 			break;
+		case NT_S390_GS_CB:
+			if (nt_s390_gs_cb_read(fh, cpu_current, &note))
+				return -EINVAL;
+			dfi_cpu_content_fac_add(DFI_CPU_CONTENT_FAC_GS);
+			break;
 		default:
 			nt_skip(fh, &note);
 			break;
diff --git a/zdump/dfo_elf.c b/zdump/dfo_elf.c
index 555d00dd..2a0ccac2 100644
--- a/zdump/dfo_elf.c
+++ b/zdump/dfo_elf.c
@@ -80,6 +80,8 @@ static void *notes_init(Elf64_Phdr *phdr, void *segment_start, u64 elf_offset)
 			ptr = nt_s390_vxrs_low(ptr, cpu);
 			ptr = nt_s390_vxrs_high(ptr, cpu);
 		}
+		if (dfi_cpu_content_fac_check(DFI_CPU_CONTENT_FAC_GS))
+			ptr = nt_s390_gs_cb(ptr, cpu);
 	}
 out:
 	ptr = nt_vmcoreinfo(ptr, dfi_vmcoreinfo_get());