From eb763bec53d6b9aea7a6b60b0cf8c5d8b5f1b35c Mon Sep 17 00:00:00 2001
From: Janosch Frank <frankja@linux.ibm.com>
Date: Thu, 7 Apr 2022 09:48:24 +0000
Subject: [PATCH 14/42] dump: Remove the sh_info variable
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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: [14/41] 24af12b78c8f5a02cf85df2f6b1d64249f9499c9
There's no need to have phdr_num and sh_info at the same time. We can
make phdr_num 32 bit and set PN_XNUM when we write the header if
phdr_num >= PN_XNUM.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220407094824.5074-1-frankja@linux.ibm.com>
(cherry picked from commit 046bc4160bc780eaacc2d702a2589f1a7a01188d)
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
dump/dump.c | 44 +++++++++++++++++++++++--------------------
include/sysemu/dump.h | 3 +--
2 files changed, 25 insertions(+), 22 deletions(-)
diff --git a/dump/dump.c b/dump/dump.c
index 9876123f2e..7236b167cc 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -124,6 +124,12 @@ static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
static void write_elf64_header(DumpState *s, Error **errp)
{
+ /*
+ * phnum in the elf header is 16 bit, if we have more segments we
+ * set phnum to PN_XNUM and write the real number of segments to a
+ * special section.
+ */
+ uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
Elf64_Ehdr elf_header;
int ret;
@@ -138,9 +144,9 @@ static void write_elf64_header(DumpState *s, Error **errp)
elf_header.e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
elf_header.e_phoff = cpu_to_dump64(s, sizeof(Elf64_Ehdr));
elf_header.e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));
- elf_header.e_phnum = cpu_to_dump16(s, s->phdr_num);
+ elf_header.e_phnum = cpu_to_dump16(s, phnum);
if (s->have_section) {
- uint64_t shoff = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr) * s->sh_info;
+ uint64_t shoff = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr) * s->phdr_num;
elf_header.e_shoff = cpu_to_dump64(s, shoff);
elf_header.e_shentsize = cpu_to_dump16(s, sizeof(Elf64_Shdr));
@@ -155,6 +161,12 @@ static void write_elf64_header(DumpState *s, Error **errp)
static void write_elf32_header(DumpState *s, Error **errp)
{
+ /*
+ * phnum in the elf header is 16 bit, if we have more segments we
+ * set phnum to PN_XNUM and write the real number of segments to a
+ * special section.
+ */
+ uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
Elf32_Ehdr elf_header;
int ret;
@@ -169,9 +181,9 @@ static void write_elf32_header(DumpState *s, Error **errp)
elf_header.e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
elf_header.e_phoff = cpu_to_dump32(s, sizeof(Elf32_Ehdr));
elf_header.e_phentsize = cpu_to_dump16(s, sizeof(Elf32_Phdr));
- elf_header.e_phnum = cpu_to_dump16(s, s->phdr_num);
+ elf_header.e_phnum = cpu_to_dump16(s, phnum);
if (s->have_section) {
- uint32_t shoff = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr) * s->sh_info;
+ uint32_t shoff = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr) * s->phdr_num;
elf_header.e_shoff = cpu_to_dump32(s, shoff);
elf_header.e_shentsize = cpu_to_dump16(s, sizeof(Elf32_Shdr));
@@ -358,12 +370,12 @@ static void write_elf_section(DumpState *s, int type, Error **errp)
if (type == 0) {
shdr_size = sizeof(Elf32_Shdr);
memset(&shdr32, 0, shdr_size);
- shdr32.sh_info = cpu_to_dump32(s, s->sh_info);
+ shdr32.sh_info = cpu_to_dump32(s, s->phdr_num);
shdr = &shdr32;
} else {
shdr_size = sizeof(Elf64_Shdr);
memset(&shdr64, 0, shdr_size);
- shdr64.sh_info = cpu_to_dump32(s, s->sh_info);
+ shdr64.sh_info = cpu_to_dump32(s, s->phdr_num);
shdr = &shdr64;
}
@@ -478,13 +490,6 @@ static void write_elf_loads(DumpState *s, Error **errp)
hwaddr offset, filesz;
MemoryMapping *memory_mapping;
uint32_t phdr_index = 1;
- uint32_t max_index;
-
- if (s->have_section) {
- max_index = s->sh_info;
- } else {
- max_index = s->phdr_num;
- }
QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
get_offset_range(memory_mapping->phys_addr,
@@ -502,7 +507,7 @@ static void write_elf_loads(DumpState *s, Error **errp)
return;
}
- if (phdr_index >= max_index) {
+ if (phdr_index >= s->phdr_num) {
break;
}
}
@@ -1809,22 +1814,21 @@ static void dump_init(DumpState *s, int fd, bool has_format,
s->phdr_num += s->list.num;
s->have_section = false;
} else {
+ /* sh_info of section 0 holds the real number of phdrs */
s->have_section = true;
- s->phdr_num = PN_XNUM;
- s->sh_info = 1; /* PT_NOTE */
/* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
if (s->list.num <= UINT32_MAX - 1) {
- s->sh_info += s->list.num;
+ s->phdr_num += s->list.num;
} else {
- s->sh_info = UINT32_MAX;
+ s->phdr_num = UINT32_MAX;
}
}
if (s->dump_info.d_class == ELFCLASS64) {
if (s->have_section) {
s->memory_offset = sizeof(Elf64_Ehdr) +
- sizeof(Elf64_Phdr) * s->sh_info +
+ sizeof(Elf64_Phdr) * s->phdr_num +
sizeof(Elf64_Shdr) + s->note_size;
} else {
s->memory_offset = sizeof(Elf64_Ehdr) +
@@ -1833,7 +1837,7 @@ static void dump_init(DumpState *s, int fd, bool has_format,
} else {
if (s->have_section) {
s->memory_offset = sizeof(Elf32_Ehdr) +
- sizeof(Elf32_Phdr) * s->sh_info +
+ sizeof(Elf32_Phdr) * s->phdr_num +
sizeof(Elf32_Shdr) + s->note_size;
} else {
s->memory_offset = sizeof(Elf32_Ehdr) +
diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
index 250143cb5a..b463fc9c02 100644
--- a/include/sysemu/dump.h
+++ b/include/sysemu/dump.h
@@ -154,8 +154,7 @@ typedef struct DumpState {
GuestPhysBlockList guest_phys_blocks;
ArchDumpInfo dump_info;
MemoryMappingList list;
- uint16_t phdr_num;
- uint32_t sh_info;
+ uint32_t phdr_num;
bool have_section;
bool resume;
bool detached;
--
2.37.3