Commit 893f38d1 authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar

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 b24c2a92 ("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: default avatarJens Axboe <jens.axboe@oracle.com>
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Tested-by: default avatarJens Axboe <jens.axboe@oracle.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
LKML-Reference: <4B21630A.6000308@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent ebb682f5
......@@ -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);
......
......@@ -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
{}
};
......
......@@ -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
......
......@@ -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
......
......@@ -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);
}
}
......
......@@ -73,6 +73,7 @@
#include <asm/mtrr.h>
#include <asm/apic.h>
#include <asm/trampoline.h>
#include <asm/e820.h>
#include <asm/mpspec.h>
#include <asm/setup.h>
......@@ -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.
......
......@@ -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");
}
/*
......
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