[PATCH] kexec-tools: handle 64bit efi memmap address correctly

[Dave Young]

In case using crashkernel=xM,high crashkernel memory will be allocated from top to down
Thus the usable memory for kdump kernel could be bigger than 4G. The efi memmap value
is two 32 bit values efi_memmap and efi_memmap_hi, previously I only passed the efi_memmap
so for the high memory address there will be below kernel panic: 

[    0.000000] efi: EFI v2.31 by American Megatrends
[    0.000000] efi:  ACPI 2.0=0xdb752000  SMBIOS=0xdbab4b98  ACPI=0xdb752000  MPS=0xf4bd0 
[    0.000000] efi: mem00: type=4294967295, attr=0xffffffffffffffff, range=[0xffffffffffffffff-0xffffffffffffefff) (72057594037927935)
[    0.000000] efi: mem01: type=4294967295, attr=0xffffffffffffffff, range=[0xffffffffffffffff-0xffffffffffffefff) (72057594037927935)
[    0.000000] efi: mem02: type=4294967295, attr=0xffffffffffffffff, range=[0xffffffffffffffff-0xffffffffffffefff) (72057594037927935)
[    0.000000] efi: mem03: type=4294967295, attr=0xffffffffffffffff, range=[0xffffffffffffffff-0xffffffffffffefff) (72057594037927935)
[    0.000000] efi: mem04: type=4294967295, attr=0xffffffffffffffff, range=[0xffffffffffffffff-0xffffffffffffefff) (72057594037927935)
[    0.000000] SMBIOS 2.7 present.

[snip]

[    0.082451] BUG: unable to handle kernel paging request at ffffa3d0f0000000
[    0.089467] IP: [<ffffffff810513d1>] native_set_pte+0x1/0x10
[    0.095157] PGD 0 
[    0.097197] Oops: 0002 [#1] SMP 
[    0.100466] Modules linked in:
[    0.103554] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc7 #157
[    0.110001] Hardware name: Hewlett-Packard HP Z420 Workstation/1589, BIOS J61 v03.15 05/09/2013
[    0.118697] task: ffffffff818e1460 ti: ffffffff818ce000 task.ti: ffffffff818ce000
[    0.126181] RIP: 0010:[<ffffffff810513d1>]  [<ffffffff810513d1>] native_set_pte+0x1/0x10
[    0.134296] RSP: 0000:ffffffff818cfc80  EFLAGS: 00010287
[    0.139609] RAX: 0000000000000000 RBX: ffffa3d0f0000000 RCX: 00003ffffffff000
[    0.146744] RDX: ffff880000000000 RSI: 0000000000000000 RDI: ffffa3d0f0000000
[    0.153879] RBP: ffffffff818cfcb8 R08: ffffea0010745d20 R09: 0000000000000000
[    0.161013] R10: ffff88041f731fc0 R11: 000000000000001e R12: 0000000000200000
[    0.168148] R13: 0000000000000000 R14: 0000000000400000 R15: ffff880000000008
[    0.175288] FS:  0000000000000000(0000) GS:ffff88041f200000(0000) knlGS:0000000000000000
[    0.183377] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.189125] CR2: ffffa3d0f0000000 CR3: 000000041e8da000 CR4: 00000000000406b0
[    0.196264] Stack:
[    0.198283]  ffffffff818cfcb8 ffffffff810561d7 ffff880000000008 0000000000400000
[    0.205746]  ffff880000001000 00000000000001ff ffff88041e8de000 ffffffff818cfd00
[    0.213210]  ffffffff8105644e 0000000000200000 0000000040000000 00000000ffffffff
[    0.220676] Call Trace:
[    0.223130]  [<ffffffff810561d7>] ? unmap_pte_range+0x77/0x110
[    0.228966]  [<ffffffff8105644e>] unmap_pmd_range+0xde/0x210
[    0.234630]  [<ffffffff81056c6b>] __cpa_process_fault+0x48b/0x5e0
[    0.240730]  [<ffffffff81057276>] __change_page_attr_set_clr+0x4b6/0xb10
[    0.247437]  [<ffffffff810557c7>] ? __ioremap_caller+0x277/0x360
[    0.253454]  [<ffffffff810589f1>] kernel_map_pages_in_pgd+0x71/0xa0
[    0.259736]  [<ffffffff81a53361>] __map_region+0x45/0x63
[    0.265051]  [<ffffffff81a535cc>] efi_map_region_fixed+0xd/0xf
[    0.270886]  [<ffffffff81a52f19>] efi_enter_virtual_mode+0x5a/0x3d9
[    0.277162]  [<ffffffff81a77516>] ? acpi_enable_subsystem+0x37/0x90
[    0.283440]  [<ffffffff81a36eb9>] start_kernel+0x386/0x41c
[    0.288931]  [<ffffffff81a3693c>] ? repair_env_string+0x5c/0x5c
[    0.294852]  [<ffffffff81a36120>] ? early_idt_handlers+0x120/0x120
[    0.301035]  [<ffffffff81a365ee>] x86_64_start_reservations+0x2a/0x2c
[    0.307479]  [<ffffffff81a3672e>] x86_64_start_kernel+0x13e/0x14d
[    0.313572] Code: 66 2e 0f 1f 84 00 00 00 00 00 48 8b 46 18 55 48 89 e5 48 89 47 04 5d c3 66 90 55 48 89 e5 0f 01 f8 5d c3 0f 1f 8 
[    0.333545] RIP  [<ffffffff810513d1>] native_set_pte+0x1/0x10
[    0.339312]  RSP <ffffffff818cfc80>
[    0.342807] CR2: ffffa3d0f0000000
[    0.346141] ---[ end trace 86088f739725b8c6 ]---
[    0.350760] Kernel panic - not syncing: Fatal exception

Fix this by passing both efi_memmap and efi_memmap_hi to 2nd kernel.

Reported-by: Linn Crosetto <linn at hp.com>
Signed-off-by: Dave Young <dyoung at redhat.com>
Tested-by: Linn Crosetto <linn at hp.com>
---
 kexec/arch/i386/x86-linux-setup.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: kexec-tools/kexec/arch/i386/x86-linux-setup.c
===================================================================
--- kexec-tools.orig/kexec/arch/i386/x86-linux-setup.c
+++ kexec-tools/kexec/arch/i386/x86-linux-setup.c
@@ -656,7 +656,8 @@ static int setup_efi_data(struct kexec_i
 	size = nr_maps * sizeof(struct efi_mem_descriptor);
 	memmap_paddr = add_buffer(info, maps, size, size, getpagesize(),
 					0x100000, ULONG_MAX, INT_MAX);
-	ei->efi_memmap = memmap_paddr;
+	ei->efi_memmap = memmap_paddr & 0xffffffff;
+	ei->efi_memmap_hi = memmap_paddr >> 32;
 	ei->efi_memmap_size = size;
 	ei->efi_memdesc_size = sizeof(struct efi_mem_descriptor);