From 893f38d144a4d96d2483cd7c3801d26e1b2c23e9 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Thu, 10 Dec 2009 13:07:22 -0800 Subject: x86: Use find_e820() instead of hard coded trampoline address Jens found the following crash/regression: [ 0.000000] found SMP MP-table at [ffff8800000fdd80] fdd80 [ 0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 0-fff BIOS data page and [ 0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 6000-7fff TRAMPOLINE and bisected it to b24c2a9 ("x86: Move find_smp_config() earlier and avoid bootmem usage"). It turns out the BIOS is using the first 64k for mptable, without reserving it. So try to find good range for the real-mode trampoline instead of hard coding it, in case some bios tries to use that range for sth. Reported-by: Jens Axboe Signed-off-by: Yinghai Lu Tested-by: Jens Axboe Cc: Randy Dunlap LKML-Reference: <4B21630A.6000308@kernel.org> Signed-off-by: Ingo Molnar diff --git a/arch/x86/include/asm/trampoline.h b/arch/x86/include/asm/trampoline.h index 90f06c2..cb507bb 100644 --- a/arch/x86/include/asm/trampoline.h +++ b/arch/x86/include/asm/trampoline.h @@ -16,7 +16,6 @@ extern unsigned long initial_code; extern unsigned long initial_gs; #define TRAMPOLINE_SIZE roundup(trampoline_end - trampoline_data, PAGE_SIZE) -#define TRAMPOLINE_BASE 0x6000 extern unsigned long setup_trampoline(void); extern void __init reserve_trampoline_memory(void); diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index d17d482..f50447d 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -732,7 +732,16 @@ struct early_res { char overlap_ok; }; static struct early_res early_res[MAX_EARLY_RES] __initdata = { - { 0, PAGE_SIZE, "BIOS data page" }, /* BIOS data page */ + { 0, PAGE_SIZE, "BIOS data page", 1 }, /* BIOS data page */ +#ifdef CONFIG_X86_32 + /* + * But first pinch a few for the stack/trampoline stuff + * FIXME: Don't need the extra page at 4K, but need to fix + * trampoline before removing it. (see the GDT stuff) + */ + { PAGE_SIZE, PAGE_SIZE, "EX TRAMPOLINE", 1 }, +#endif + {} }; diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c index 4f8e250..5051b94 100644 --- a/arch/x86/kernel/head32.c +++ b/arch/x86/kernel/head32.c @@ -29,8 +29,6 @@ static void __init i386_default_early_setup(void) void __init i386_start_kernel(void) { - reserve_trampoline_memory(); - reserve_early(__pa_symbol(&_text), __pa_symbol(&__bss_stop), "TEXT DATA BSS"); #ifdef CONFIG_BLK_DEV_INITRD diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 0b06cd7..b5a9896 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -98,8 +98,6 @@ void __init x86_64_start_reservations(char *real_mode_data) { copy_bootdata(__va(real_mode_data)); - reserve_trampoline_memory(); - reserve_early(__pa_symbol(&_text), __pa_symbol(&__bss_stop), "TEXT DATA BSS"); #ifdef CONFIG_BLK_DEV_INITRD diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c index 35a57c9..40b54ce 100644 --- a/arch/x86/kernel/mpparse.c +++ b/arch/x86/kernel/mpparse.c @@ -945,9 +945,6 @@ void __init early_reserve_e820_mpc_new(void) { if (enable_update_mptable && alloc_mptable) { u64 startt = 0; -#ifdef CONFIG_X86_TRAMPOLINE - startt = TRAMPOLINE_BASE; -#endif mpc_new_phys = early_reserve_e820(startt, mpc_new_length, 4); } } diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 946a311..f7b8b98 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -73,6 +73,7 @@ #include #include +#include #include #include #include @@ -875,6 +876,13 @@ void __init setup_arch(char **cmdline_p) reserve_brk(); + /* + * Find and reserve possible boot-time SMP configuration: + */ + find_smp_config(); + + reserve_trampoline_memory(); + #ifdef CONFIG_ACPI_SLEEP /* * Reserve low memory region for sleep support. @@ -921,11 +929,6 @@ void __init setup_arch(char **cmdline_p) early_acpi_boot_init(); - /* - * Find and reserve possible boot-time SMP configuration: - */ - find_smp_config(); - #ifdef CONFIG_ACPI_NUMA /* * Parse SRAT to discover nodes. diff --git a/arch/x86/kernel/trampoline.c b/arch/x86/kernel/trampoline.c index cd02212..c652ef6 100644 --- a/arch/x86/kernel/trampoline.c +++ b/arch/x86/kernel/trampoline.c @@ -12,21 +12,19 @@ #endif /* ready for x86_64 and x86 */ -unsigned char *__trampinitdata trampoline_base = __va(TRAMPOLINE_BASE); +unsigned char *__trampinitdata trampoline_base; void __init reserve_trampoline_memory(void) { -#ifdef CONFIG_X86_32 - /* - * But first pinch a few for the stack/trampoline stuff - * FIXME: Don't need the extra page at 4K, but need to fix - * trampoline before removing it. (see the GDT stuff) - */ - reserve_early(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE, "EX TRAMPOLINE"); -#endif + unsigned long mem; + /* Has to be in very low memory so we can execute real-mode AP code. */ - reserve_early(TRAMPOLINE_BASE, TRAMPOLINE_BASE + TRAMPOLINE_SIZE, - "TRAMPOLINE"); + mem = find_e820_area(0, 1<<20, TRAMPOLINE_SIZE, PAGE_SIZE); + if (mem == -1L) + panic("Cannot allocate trampoline\n"); + + trampoline_base = __va(mem); + reserve_early(mem, mem + TRAMPOLINE_SIZE, "TRAMPOLINE"); } /* -- cgit v0.10.2