Messages in this thread Patch in this message |  | | | Date | Sat, 5 Sep 2009 23:56:18 -0700 | | Subject | Re: linux-next: reservetop fix disables mem= | | From | Yinghai Lu <> |
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On Mon, Aug 24, 2009 at 11:27 AM, Ingo Molnar<mingo@elte.hu> wrote: > > * Yinghai Lu <yinghai@kernel.org> wrote: > >> Hugh Dickins wrote: >> > I find the "mem=" boot parameter disabled in today's linux-next: >> > reverting the tip commit below fixes that. >> > >> > Hugh >> > >> > From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> >> > Date: Thu, 20 Aug 2009 12:23:11 +0000 (+0800) >> > Subject: x86: Fix system crash when loading with "reservetop" parameter >> > X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fmingo%2Flinux-2.6-x86.git;a=commitdiff_plain;h=8126dec32738421afa362114337331337b4be17f >> > >> > x86: Fix system crash when loading with "reservetop" parameter >> > >> > The system will die if the kernel is booted with "reservetop" >> > parameter, in present code, parse "reservetop" parameter after >> > early_ioremap_init(), and some function still use >> > early_ioremap() after it. >> > >> > The problem is, "reservetop" parameter can modify >> > 'FIXADDR_TOP', then the virtual address got by early_ioremap() >> > is base on old 'FIXADDR_TOP', but the page mapping is base on >> > new 'FIXADDR_TOP', it will occur page fault, and the IDT is not >> > prepare yet, so, the system is dead. >> > >> > So, put parse_early_param() in the front of >> > early_ioremap_init() in this patch. >> > >> > Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> >> > Cc: yinghai@kernel.org >> > Cc: Andrew Morton <akpm@linux-foundation.org> >> > LKML-Reference: <4A8D402F.4080805@cn.fujitsu.com> >> > Signed-off-by: Ingo Molnar <mingo@elte.hu> >> > --- >> > >> > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c >> > index 63f32d2..02643cc 100644 >> > --- a/arch/x86/kernel/setup.c >> > +++ b/arch/x86/kernel/setup.c >> > @@ -711,6 +711,11 @@ void __init setup_arch(char **cmdline_p) >> > printk(KERN_INFO "Command line: %s\n", boot_command_line); >> > #endif >> > >> > + strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); >> > + *cmdline_p = command_line; >> > + >> > + parse_early_param(); >> > + >> > /* VMI may relocate the fixmap; do this before touching ioremap area */ >> > vmi_init(); >> > >> > @@ -793,11 +798,6 @@ void __init setup_arch(char **cmdline_p) >> > #endif >> > #endif >> > >> > - strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); >> > - *cmdline_p = command_line; >> > - >> > - parse_early_param(); >> > - >> > #ifdef CONFIG_X86_64 >> > check_efer(); >> > #endif >> >> yes, that patch will break other built-in command too. >> >> need drop that patch. > > done. Was nervous about the patch already: > > http://lkml.org/lkml/2009/8/21/127 > >> also the problem was caused by vmi patch, and that commit should >> be reverted. >> >> commit ae8d04e2ecbb233926860e9ce145eac19c7835dc >> Author: Zachary Amsden <zach@vmware.com> >> Date: Sat Dec 13 12:36:58 2008 -0800 >> >> x86 Fix VMI crash on boot in 2.6.28-rc8 >> >> VMI initialiation can relocate the fixmap, causing early_ioremap to >> malfunction if it is initialized before the relocation. To fix this, >> VMI activation is split into two phases; the detection, which must >> happen before setting up ioremap, and the activation, which must happen >> after parsing early boot parameters. >> >> This fixes a crash on boot when VMI is enabled under VMware. >> >> Signed-off-by: Zachary Amsden <zach@vmware.com> >> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> >> >> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c >> index 9d5674f..bdec76e 100644 >> --- a/arch/x86/kernel/setup.c >> +++ b/arch/x86/kernel/setup.c >> @@ -794,6 +794,9 @@ void __init setup_arch(char **cmdline_p) >> printk(KERN_INFO "Command line: %s\n", boot_command_line); >> #endif >> >> + /* VMI may relocate the fixmap; do this before touching ioremap area */ >> + vmi_init(); >> + >> early_cpu_init(); >> early_ioremap_init(); >> >> @@ -880,13 +883,8 @@ void __init setup_arch(char **cmdline_p) >> check_efer(); >> #endif >> >> -#if defined(CONFIG_VMI) && defined(CONFIG_X86_32) >> - /* >> - * Must be before kernel pagetables are setup >> - * or fixmap area is touched. >> - */ >> - vmi_init(); >> -#endif >> + /* Must be before kernel pagetables are setup */ >> + vmi_activate(); >> >> /* after early param, so could get panic from serial */ >> reserve_early_setup_data(); >> >> >> and according to >> http://lkml.org/lkml/2008/12/10/388 >> http://lkml.org/lkml/2008/12/10/456 >> >> Zachary should split reserve_top_address() to two functions... >> before sending that patch to Linus > > mind looking at this yourself if interested? Zachary has not been > active for quite some time. >
please check attached patch...
still need to make early_dbgp and early_console that would use early_ioremap?
YH [PATCH] x86: fix early_param hanle moved more early
the patch the move early_param_parse early to make reservetop to work again, it is reported to break mem=...
after close looking, it will break 1. some cpu feature in early stage too, like cpu_has_x2apic 2. will break built-in-command line 3. will break other memmap= and mem= 4. early_dbgp and early_console that will use early_ioremap to access mmio (?)
so try to 1. move early_cpu_init early 2. move built-in-command copying early 3. add userdef_mem_size to remember mem= . add e820_user to remember memmap to use userdef_mem_size and e820_user in finalize_map 4: ?
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
--- arch/x86/kernel/e820.c | 52 ++++++++++++++++++++++++++++++++---------------- arch/x86/kernel/setup.c | 39 ++++++++++++++++++------------------ 2 files changed, 55 insertions(+), 36 deletions(-) Index: linux-2.6/arch/x86/kernel/e820.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/e820.c +++ linux-2.6/arch/x86/kernel/e820.c @@ -44,6 +44,7 @@ */ struct e820map e820; struct e820map e820_saved; +static struct e820map e820_user __initdata; /* For PCI or other memory-mapped resources */ unsigned long pci_mem_start = 0xaeedbabe; @@ -1227,11 +1228,11 @@ static void early_panic(char *msg) } static int userdef __initdata; +static u64 userdef_mem_size __initdata; /* "mem=nopentium" disables the 4MB page tables. */ static int __init parse_memopt(char *p) { - u64 mem_size; if (!p) return -EINVAL; @@ -1244,13 +1245,13 @@ static int __init parse_memopt(char *p) #endif userdef = 1; - mem_size = memparse(p, &p); - e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1); + userdef_mem_size = memparse(p, &p); return 0; } early_param("mem", parse_memopt); +static int userdef_exactmap __initdata; static int __init parse_memmap_opt(char *p) { char *oldp; @@ -1260,16 +1261,9 @@ static int __init parse_memmap_opt(char return -EINVAL; if (!strncmp(p, "exactmap", 8)) { -#ifdef CONFIG_CRASH_DUMP - /* - * If we are doing a crash dump, we still need to know - * the real mem size before original memory map is - * reset. - */ - saved_max_pfn = e820_end_of_ram_pfn(); -#endif - e820.nr_map = 0; + e820_user.nr_map = 0; userdef = 1; + userdef_exactmap = 1; return 0; } @@ -1281,15 +1275,16 @@ static int __init parse_memmap_opt(char userdef = 1; if (*p == '@') { start_at = memparse(p+1, &p); - e820_add_region(start_at, mem_size, E820_RAM); + __e820_add_region(&e820_user, start_at, mem_size, E820_RAM); } else if (*p == '#') { start_at = memparse(p+1, &p); - e820_add_region(start_at, mem_size, E820_ACPI); + __e820_add_region(&e820_user, start_at, mem_size, E820_ACPI); } else if (*p == '$') { start_at = memparse(p+1, &p); - e820_add_region(start_at, mem_size, E820_RESERVED); + __e820_add_region(&e820_user, start_at, mem_size, + E820_RESERVED); } else - e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1); + userdef_mem_size = mem_size; return *p == '\0' ? 0 : -EINVAL; } @@ -1298,7 +1293,30 @@ early_param("memmap", parse_memmap_opt); void __init finish_e820_parsing(void) { if (userdef) { - u32 nr = e820.nr_map; + u32 nr; + + if (userdef_exactmap) { +#ifdef CONFIG_CRASH_DUMP + /* + * If we are doing a crash dump, we still need to know + * the real mem size before original memory map is + * reset. + */ + saved_max_pfn = e820_end_of_ram_pfn(); +#endif + /* good, just use e820_user instead */ + memcpy(&e820, &e820_user, sizeof(struct e820map)); + } else { + /* ok, need to append e820_user to e820 */ + __append_e820_map(e820_user.map, e820_user.nr_map); + } + + nr = e820.nr_map; + + if (userdef_mem_size) + e820_remove_range(userdef_mem_size, + ULLONG_MAX - userdef_mem_size, + E820_RAM, 1); if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0) early_panic("Invalid user supplied memory map"); Index: linux-2.6/arch/x86/kernel/setup.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/setup.c +++ linux-2.6/arch/x86/kernel/setup.c @@ -693,13 +693,28 @@ void __init setup_arch(char **cmdline_p) #ifdef CONFIG_X86_32 memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data)); visws_early_detect(); +#endif + +#ifdef CONFIG_CMDLINE_BOOL +#ifdef CONFIG_CMDLINE_OVERRIDE + strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); #else - printk(KERN_INFO "Command line: %s\n", boot_command_line); + if (builtin_cmdline[0]) { + /* append boot loader cmdline to builtin */ + strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE); + strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE); + strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); + } +#endif #endif + printk(KERN_INFO "Command line: %s\n", boot_command_line); + strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); *cmdline_p = command_line; + early_cpu_init(); + #ifdef CONFIG_X86_64 /* * Must call this twice: Once just to detect whether hardware doesn't @@ -712,10 +727,13 @@ void __init setup_arch(char **cmdline_p) parse_early_param(); +#ifdef CONFIG_X86_64 + check_efer(); +#endif + /* VMI may relocate the fixmap; do this before touching ioremap area */ vmi_init(); - early_cpu_init(); early_ioremap_init(); ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev); @@ -781,23 +799,6 @@ void __init setup_arch(char **cmdline_p) bss_resource.start = virt_to_phys(&__bss_start); bss_resource.end = virt_to_phys(&__bss_stop)-1; -#ifdef CONFIG_CMDLINE_BOOL -#ifdef CONFIG_CMDLINE_OVERRIDE - strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); -#else - if (builtin_cmdline[0]) { - /* append boot loader cmdline to builtin */ - strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE); - strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE); - strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); - } -#endif -#endif - -#ifdef CONFIG_X86_64 - check_efer(); -#endif - /* Must be before kernel pagetables are setup */ vmi_activate(); |  |