* ELF64 header on i386 @ 2007-07-02 13:15 Bernhard Walle 2007-07-03 5:12 ` Maneesh Soni 2007-07-03 16:12 ` [PATCH] Determine ELF32/ELF64 automatically " Bernhard Walle 0 siblings, 2 replies; 6+ messages in thread From: Bernhard Walle @ 2007-07-02 13:15 UTC (permalink / raw) To: kexec Hello, why creates kexec-tools ELF64 headers per default on i386? Wouldn't it make more sense to look if a physical address exceeds the 32-bit limit and then switch to ELF64 automatically if the user doesn't have specified an option? Thanks, Bernhard _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: ELF64 header on i386 2007-07-02 13:15 ELF64 header on i386 Bernhard Walle @ 2007-07-03 5:12 ` Maneesh Soni 2007-07-03 16:12 ` [PATCH] Determine ELF32/ELF64 automatically " Bernhard Walle 1 sibling, 0 replies; 6+ messages in thread From: Maneesh Soni @ 2007-07-03 5:12 UTC (permalink / raw) To: kexec On Mon, Jul 02, 2007 at 03:15:41PM +0200, Bernhard Walle wrote: > Hello, > > why creates kexec-tools ELF64 headers per default on i386? Wouldn't it > make more sense to look if a physical address exceeds the 32-bit limit > and then switch to ELF64 automatically if the user doesn't have > specified an option? > I am aware of one issue, that gdb on i386 is not able to analyse ELF64 formatted kdump though "crash" can. Thanks Maneesh -- Maneesh Soni Linux Technology Center, IBM India Systems and Technology Lab, Bangalore, India _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] Determine ELF32/ELF64 automatically on i386 2007-07-02 13:15 ELF64 header on i386 Bernhard Walle 2007-07-03 5:12 ` Maneesh Soni @ 2007-07-03 16:12 ` Bernhard Walle 2007-07-10 5:52 ` Vivek Goyal 1 sibling, 1 reply; 6+ messages in thread From: Bernhard Walle @ 2007-07-03 16:12 UTC (permalink / raw) To: kexec On i386, kexec generates ELF64 core headers by default if the user doesn't override this via a command line option. Because GDB cannot analyse ELF64 core dumps on 32 bit platforms, it's a bad idea to use ELF64 if it's not needed. This patch selects ELF32 if the biggest memory address fits in 32 bit address space, which should be the case on non PAE systems. If the user specifies a command line option, that option overrides the detection. Signed-off-by: Bernhard Walle <bwalle@suse.de> --- kexec/arch/i386/crashdump-x86.c | 26 ++++++++++++++++++++++++++ kexec/arch/i386/kexec-x86.c | 2 +- kexec/arch/i386/kexec-x86.h | 20 ++++++++++++-------- 3 files changed, 39 insertions(+), 9 deletions(-) --- a/kexec/arch/i386/crashdump-x86.c +++ b/kexec/arch/i386/crashdump-x86.c @@ -486,6 +486,23 @@ static struct crash_elf_info elf_info32 get_note_info: get_crash_notes, }; +static enum CoreType get_core_type(struct kexec_info *info, + struct memory_range *range, int ranges) +{ + if (info->kexec_flags & KEXEC_ARCH_X86_64) + return CORE_TYPE_ELF64; + else { + /* fall back to default */ + if (ranges == 0) + return CORE_TYPE_ELF64; + + if (range[ranges].end > 0xFFFFFFFFUL) + return CORE_TYPE_ELF64; + else + return CORE_TYPE_ELF32; + } +} + /* Loads additional segments in case of a panic kernel is being loaded. * One segment for backup region, another segment for storing elf headers * for crash memory image. @@ -501,6 +518,15 @@ int load_crashdump_segments(struct kexec if (get_crash_memory_ranges(&mem_range, &nr_ranges) < 0) return -1; + /* + * if the core type has not been set on command line, set it here + * automatically + */ + if (arch_options.core_header_type == CORE_TYPE_UNDEF) { + arch_options.core_header_type = + get_core_type(info, mem_range, nr_ranges); + } + /* Memory regions which panic kernel can safely use to boot into */ sz = (sizeof(struct memory_range) * (KEXEC_MAX_SEGMENTS + 1)); memmap_p = xmalloc(sz); --- a/kexec/arch/i386/kexec-x86.c +++ b/kexec/arch/i386/kexec-x86.c @@ -145,7 +145,7 @@ struct arch_options_t arch_options = { .serial_baud = 0, .console_vga = 0, .console_serial = 0, - .core_header_type = CORE_TYPE_ELF64, + .core_header_type = CORE_TYPE_UNDEF, }; int arch_process_options(int argc, char **argv) --- a/kexec/arch/i386/kexec-x86.h +++ b/kexec/arch/i386/kexec-x86.h @@ -2,8 +2,12 @@ #define KEXEC_X86_H #define MAX_MEMORY_RANGES 64 -#define CORE_TYPE_ELF32 1 -#define CORE_TYPE_ELF64 2 + +enum CoreType { + CORE_TYPE_UNDEF = 0, + CORE_TYPE_ELF32 = 1, + CORE_TYPE_ELF64 = 2 +}; extern unsigned char compat_x86_64[]; extern uint32_t compat_x86_64_size, compat_x86_64_entry32; @@ -40,12 +44,12 @@ struct entry16_regs { }; struct arch_options_t { - uint8_t reset_vga; - uint16_t serial_base; - uint32_t serial_baud; - uint8_t console_vga; - uint8_t console_serial; - int core_header_type; + uint8_t reset_vga; + uint16_t serial_base; + uint32_t serial_baud; + uint8_t console_vga; + uint8_t console_serial; + enum CoreType core_header_type; }; int multiboot_x86_probe(const char *buf, off_t len); _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Determine ELF32/ELF64 automatically on i386 2007-07-03 16:12 ` [PATCH] Determine ELF32/ELF64 automatically " Bernhard Walle @ 2007-07-10 5:52 ` Vivek Goyal 2007-07-10 8:23 ` Bernhard Walle 0 siblings, 1 reply; 6+ messages in thread From: Vivek Goyal @ 2007-07-10 5:52 UTC (permalink / raw) To: kexec On Tue, Jul 03, 2007 at 06:12:07PM +0200, Bernhard Walle wrote: > On i386, kexec generates ELF64 core headers by default if the user doesn't > override this via a command line option. Because GDB cannot analyse > ELF64 core dumps on 32 bit platforms, it's a bad idea to use ELF64 if it's not > needed. > > This patch selects ELF32 if the biggest memory address fits in 32 bit address > space, which should be the case on non PAE systems. If the user specifies > a command line option, that option overrides the detection. > Makes sense to me. No need to generate 64bit ELF headers on systems having less than 4G of memory. gdb runs into issues with 64bit ELF headers on 32bit machines. > +++ b/kexec/arch/i386/kexec-x86.h > @@ -2,8 +2,12 @@ > #define KEXEC_X86_H > > #define MAX_MEMORY_RANGES 64 > -#define CORE_TYPE_ELF32 1 > -#define CORE_TYPE_ELF64 2 > + > +enum CoreType { > + CORE_TYPE_UNDEF = 0, > + CORE_TYPE_ELF32 = 1, > + CORE_TYPE_ELF64 = 2 > +}; > I think we can avoid mixed case in "CoreType" and use something like "coretype". Thanks Vivek _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Determine ELF32/ELF64 automatically on i386 2007-07-10 5:52 ` Vivek Goyal @ 2007-07-10 8:23 ` Bernhard Walle 2007-07-27 5:12 ` Horms 0 siblings, 1 reply; 6+ messages in thread From: Bernhard Walle @ 2007-07-10 8:23 UTC (permalink / raw) To: kexec * Vivek Goyal <vgoyal@in.ibm.com> [2007-07-10 07:52]: > On Tue, Jul 03, 2007 at 06:12:07PM +0200, Bernhard Walle wrote: > > On i386, kexec generates ELF64 core headers by default if the user doesn't > > override this via a command line option. Because GDB cannot analyse > > ELF64 core dumps on 32 bit platforms, it's a bad idea to use ELF64 if it's not > > needed. > > > > This patch selects ELF32 if the biggest memory address fits in 32 bit address > > space, which should be the case on non PAE systems. If the user specifies > > a command line option, that option overrides the detection. > > > > Makes sense to me. No need to generate 64bit ELF headers on systems > having less than 4G of memory. gdb runs into issues with 64bit ELF headers > on 32bit machines. Exaclty that was my point. > I think we can avoid mixed case in "CoreType" and use something like > "coretype". Of course: ---- [PATCH] Determine ELF32/ELF64 automatically on i386 On i386, kexec generates ELF64 core headers by default if the user doesn't override this via a command line option. Because GDB cannot analyse ELF64 core dumps on 32 bit platforms, it's a bad idea to use ELF64 if it's not needed. This patch selects ELF32 if the biggest memory address fits in 32 bit address space, which should be the case on non PAE systems. If the user specifies a command line option, that option overrides the detection. Signed-off-by: Bernhard Walle <bwalle@suse.de> --- kexec/arch/i386/crashdump-x86.c | 26 ++++++++++++++++++++++++++ kexec/arch/i386/kexec-x86.c | 2 +- kexec/arch/i386/kexec-x86.h | 20 ++++++++++++-------- 3 files changed, 39 insertions(+), 9 deletions(-) --- a/kexec/arch/i386/crashdump-x86.c +++ b/kexec/arch/i386/crashdump-x86.c @@ -486,6 +486,23 @@ static struct crash_elf_info elf_info32 get_note_info: get_crash_notes, }; +static enum coretype get_core_type(struct kexec_info *info, + struct memory_range *range, int ranges) +{ + if (info->kexec_flags & KEXEC_ARCH_X86_64) + return CORE_TYPE_ELF64; + else { + /* fall back to default */ + if (ranges == 0) + return CORE_TYPE_ELF64; + + if (range[ranges].end > 0xFFFFFFFFUL) + return CORE_TYPE_ELF64; + else + return CORE_TYPE_ELF32; + } +} + /* Loads additional segments in case of a panic kernel is being loaded. * One segment for backup region, another segment for storing elf headers * for crash memory image. @@ -501,6 +518,15 @@ int load_crashdump_segments(struct kexec if (get_crash_memory_ranges(&mem_range, &nr_ranges) < 0) return -1; + /* + * if the core type has not been set on command line, set it here + * automatically + */ + if (arch_options.core_header_type == CORE_TYPE_UNDEF) { + arch_options.core_header_type = + get_core_type(info, mem_range, nr_ranges); + } + /* Memory regions which panic kernel can safely use to boot into */ sz = (sizeof(struct memory_range) * (KEXEC_MAX_SEGMENTS + 1)); memmap_p = xmalloc(sz); --- a/kexec/arch/i386/kexec-x86.c +++ b/kexec/arch/i386/kexec-x86.c @@ -145,7 +145,7 @@ struct arch_options_t arch_options = { .serial_baud = 0, .console_vga = 0, .console_serial = 0, - .core_header_type = CORE_TYPE_ELF64, + .core_header_type = CORE_TYPE_UNDEF, }; int arch_process_options(int argc, char **argv) --- a/kexec/arch/i386/kexec-x86.h +++ b/kexec/arch/i386/kexec-x86.h @@ -2,8 +2,12 @@ #define KEXEC_X86_H #define MAX_MEMORY_RANGES 64 -#define CORE_TYPE_ELF32 1 -#define CORE_TYPE_ELF64 2 + +enum coretype { + CORE_TYPE_UNDEF = 0, + CORE_TYPE_ELF32 = 1, + CORE_TYPE_ELF64 = 2 +}; extern unsigned char compat_x86_64[]; extern uint32_t compat_x86_64_size, compat_x86_64_entry32; @@ -40,12 +44,12 @@ struct entry16_regs { }; struct arch_options_t { - uint8_t reset_vga; - uint16_t serial_base; - uint32_t serial_baud; - uint8_t console_vga; - uint8_t console_serial; - int core_header_type; + uint8_t reset_vga; + uint16_t serial_base; + uint32_t serial_baud; + uint8_t console_vga; + uint8_t console_serial; + enum coretype core_header_type; }; int multiboot_x86_probe(const char *buf, off_t len); _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Determine ELF32/ELF64 automatically on i386 2007-07-10 8:23 ` Bernhard Walle @ 2007-07-27 5:12 ` Horms 0 siblings, 0 replies; 6+ messages in thread From: Horms @ 2007-07-27 5:12 UTC (permalink / raw) To: kexec; +Cc: Vivek Goyal On Tue, Jul 10, 2007 at 10:23:16AM +0200, Bernhard Walle wrote: > * Vivek Goyal <vgoyal@in.ibm.com> [2007-07-10 07:52]: > > On Tue, Jul 03, 2007 at 06:12:07PM +0200, Bernhard Walle wrote: > > > On i386, kexec generates ELF64 core headers by default if the user doesn't > > > override this via a command line option. Because GDB cannot analyse > > > ELF64 core dumps on 32 bit platforms, it's a bad idea to use ELF64 if it's not > > > needed. > > > > > > This patch selects ELF32 if the biggest memory address fits in 32 bit address > > > space, which should be the case on non PAE systems. If the user specifies > > > a command line option, that option overrides the detection. > > > > > > > Makes sense to me. No need to generate 64bit ELF headers on systems > > having less than 4G of memory. gdb runs into issues with 64bit ELF headers > > on 32bit machines. > > Exaclty that was my point. > > > I think we can avoid mixed case in "CoreType" and use something like > > "coretype". > > Of course: > > ---- > > [PATCH] Determine ELF32/ELF64 automatically on i386 > > On i386, kexec generates ELF64 core headers by default if the user doesn't > override this via a command line option. Because GDB cannot analyse > ELF64 core dumps on 32 bit platforms, it's a bad idea to use ELF64 if it's not > needed. > > This patch selects ELF32 if the biggest memory address fits in 32 bit address > space, which should be the case on non PAE systems. If the user specifies > a command line option, that option overrides the detection. Sorry for being slow, I missed the patch earlier as it wasn't CCed to me. I have applied it now. -- Horms H: http://www.vergenet.net/~horms/ W: http://www.valinux.co.jp/en/ _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2007-07-27 5:12 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2007-07-02 13:15 ELF64 header on i386 Bernhard Walle 2007-07-03 5:12 ` Maneesh Soni 2007-07-03 16:12 ` [PATCH] Determine ELF32/ELF64 automatically " Bernhard Walle 2007-07-10 5:52 ` Vivek Goyal 2007-07-10 8:23 ` Bernhard Walle 2007-07-27 5:12 ` Horms
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox