From eb763bec53d6b9aea7a6b60b0cf8c5d8b5f1b35c Mon Sep 17 00:00:00 2001 From: Janosch Frank 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 RH-MergeRequest: 226: s390: Enhanced Interpretation for PCI Functions and Secure Execution guest dump RH-Bugzilla: 1664378 2043909 RH-Acked-by: Thomas Huth RH-Acked-by: Cornelia Huck RH-Acked-by: Jon Maloy 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 Reviewed-by: Richard Henderson Reviewed-by: Marc-André Lureau Message-Id: <20220407094824.5074-1-frankja@linux.ibm.com> (cherry picked from commit 046bc4160bc780eaacc2d702a2589f1a7a01188d) Signed-off-by: Cédric Le Goater --- 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