From d1e147a3133d4d31d4b0c02c05916366fadd9c30 Mon Sep 17 00:00:00 2001

From: Janosch Frank <frankja@linux.ibm.com>

Date: Thu, 11 Aug 2022 12:11:00 +0000

Subject: [PATCH 28/42] dump: Split elf header functions into prepare and write

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Content-Transfer-Encoding: 8bit

RH-Author: Cédric Le Goater <clg@redhat.com>

RH-MergeRequest: 226: s390: Enhanced Interpretation for PCI Functions and Secure Execution guest dump

RH-Bugzilla: 1664378 2043909

RH-Acked-by: Thomas Huth <thuth@redhat.com>

RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

RH-Acked-by: Jon Maloy <jmaloy@redhat.com>

RH-Commit: [28/41] f70a13ad443835e7f46b7c5e176e372d370ac797

Let's split the write from the modification of the elf header so we

can consolidate the write of the data in one function.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

Reviewed-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Message-Id: <20220811121111.9878-8-frankja@linux.ibm.com>

(cherry picked from commit 670e76998a61ca171200fcded3865b294a2d1243)

Signed-off-by: Cédric Le Goater <clg@redhat.com>

---

 dump/dump.c | 100 ++++++++++++++++++++++++++++------------------------

 1 file changed, 53 insertions(+), 47 deletions(-)

diff --git a/dump/dump.c b/dump/dump.c

index 902a85ef8e..8d5226f861 100644

--- a/dump/dump.c

+++ b/dump/dump.c

@@ -132,7 +132,7 @@ static int fd_write_vmcore(const void *buf, size_t size, void *opaque)

     return 0;

 }

-static void write_elf64_header(DumpState *s, Error **errp)

+static void prepare_elf64_header(DumpState *s, Elf64_Ehdr *elf_header)

 {

     /*

      * phnum in the elf header is 16 bit, if we have more segments we

@@ -140,34 +140,27 @@ static void write_elf64_header(DumpState *s, Error **errp)

      * special section.

      */

     uint16_t phnum = MIN(s->phdr_num, PN_XNUM);

-    Elf64_Ehdr elf_header;

-    int ret;

-    memset(&elf_header, 0, sizeof(Elf64_Ehdr));

-    memcpy(&elf_header, ELFMAG, SELFMAG);

-    elf_header.e_ident[EI_CLASS] = ELFCLASS64;

-    elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;

-    elf_header.e_ident[EI_VERSION] = EV_CURRENT;

-    elf_header.e_type = cpu_to_dump16(s, ET_CORE);

-    elf_header.e_machine = cpu_to_dump16(s, s->dump_info.d_machine);

-    elf_header.e_version = cpu_to_dump32(s, EV_CURRENT);

-    elf_header.e_ehsize = cpu_to_dump16(s, sizeof(elf_header));

-    elf_header.e_phoff = cpu_to_dump64(s, s->phdr_offset);

-    elf_header.e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));

-    elf_header.e_phnum = cpu_to_dump16(s, phnum);

+    memset(elf_header, 0, sizeof(Elf64_Ehdr));

+    memcpy(elf_header, ELFMAG, SELFMAG);

+    elf_header->e_ident[EI_CLASS] = ELFCLASS64;

+    elf_header->e_ident[EI_DATA] = s->dump_info.d_endian;

+    elf_header->e_ident[EI_VERSION] = EV_CURRENT;

+    elf_header->e_type = cpu_to_dump16(s, ET_CORE);

+    elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);

+    elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);

+    elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));

+    elf_header->e_phoff = cpu_to_dump64(s, s->phdr_offset);

+    elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));

+    elf_header->e_phnum = cpu_to_dump16(s, phnum);

     if (s->shdr_num) {

-        elf_header.e_shoff = cpu_to_dump64(s, s->shdr_offset);

-        elf_header.e_shentsize = cpu_to_dump16(s, sizeof(Elf64_Shdr));

-        elf_header.e_shnum = cpu_to_dump16(s, s->shdr_num);

-    }

-

-    ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);

-    if (ret < 0) {

-        error_setg_errno(errp, -ret, "dump: failed to write elf header");

+        elf_header->e_shoff = cpu_to_dump64(s, s->shdr_offset);

+        elf_header->e_shentsize = cpu_to_dump16(s, sizeof(Elf64_Shdr));

+        elf_header->e_shnum = cpu_to_dump16(s, s->shdr_num);

     }

 }

-static void write_elf32_header(DumpState *s, Error **errp)

+static void prepare_elf32_header(DumpState *s, Elf32_Ehdr *elf_header)

 {

     /*

      * phnum in the elf header is 16 bit, if we have more segments we

@@ -175,28 +168,45 @@ static void write_elf32_header(DumpState *s, Error **errp)

      * special section.

      */

     uint16_t phnum = MIN(s->phdr_num, PN_XNUM);

-    Elf32_Ehdr elf_header;

-    int ret;

-    memset(&elf_header, 0, sizeof(Elf32_Ehdr));

-    memcpy(&elf_header, ELFMAG, SELFMAG);

-    elf_header.e_ident[EI_CLASS] = ELFCLASS32;

-    elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;

-    elf_header.e_ident[EI_VERSION] = EV_CURRENT;

-    elf_header.e_type = cpu_to_dump16(s, ET_CORE);

-    elf_header.e_machine = cpu_to_dump16(s, s->dump_info.d_machine);

-    elf_header.e_version = cpu_to_dump32(s, EV_CURRENT);

-    elf_header.e_ehsize = cpu_to_dump16(s, sizeof(elf_header));

-    elf_header.e_phoff = cpu_to_dump32(s, s->phdr_offset);

-    elf_header.e_phentsize = cpu_to_dump16(s, sizeof(Elf32_Phdr));

-    elf_header.e_phnum = cpu_to_dump16(s, phnum);

+    memset(elf_header, 0, sizeof(Elf32_Ehdr));

+    memcpy(elf_header, ELFMAG, SELFMAG);

+    elf_header->e_ident[EI_CLASS] = ELFCLASS32;

+    elf_header->e_ident[EI_DATA] = s->dump_info.d_endian;

+    elf_header->e_ident[EI_VERSION] = EV_CURRENT;

+    elf_header->e_type = cpu_to_dump16(s, ET_CORE);

+    elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);

+    elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);

+    elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));

+    elf_header->e_phoff = cpu_to_dump32(s, s->phdr_offset);

+    elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf32_Phdr));

+    elf_header->e_phnum = cpu_to_dump16(s, phnum);

     if (s->shdr_num) {

-        elf_header.e_shoff = cpu_to_dump32(s, s->shdr_offset);

-        elf_header.e_shentsize = cpu_to_dump16(s, sizeof(Elf32_Shdr));

-        elf_header.e_shnum = cpu_to_dump16(s, s->shdr_num);

+        elf_header->e_shoff = cpu_to_dump32(s, s->shdr_offset);

+        elf_header->e_shentsize = cpu_to_dump16(s, sizeof(Elf32_Shdr));

+        elf_header->e_shnum = cpu_to_dump16(s, s->shdr_num);

     }

+}

-    ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);

+static void write_elf_header(DumpState *s, Error **errp)

+{

+    Elf32_Ehdr elf32_header;

+    Elf64_Ehdr elf64_header;

+    size_t header_size;

+    void *header_ptr;

+    int ret;

+

+    if (dump_is_64bit(s)) {

+        prepare_elf64_header(s, &elf64_header);

+        header_size = sizeof(elf64_header);

+        header_ptr = &elf64_header;

+    } else {

+        prepare_elf32_header(s, &elf32_header);

+        header_size = sizeof(elf32_header);

+        header_ptr = &elf32_header;

+    }

+

+    ret = fd_write_vmcore(header_ptr, header_size, s);

     if (ret < 0) {

         error_setg_errno(errp, -ret, "dump: failed to write elf header");

     }

@@ -565,11 +575,7 @@ static void dump_begin(DumpState *s, Error **errp)

      */

     /* write elf header to vmcore */

-    if (dump_is_64bit(s)) {

-        write_elf64_header(s, errp);

-    } else {

-        write_elf32_header(s, errp);

-    }

+    write_elf_header(s, errp);

     if (*errp) {

         return;

     }

-- 

2.37.3