From 0feb109818c53bf1f7e6acd55ca02a119855b77b Mon Sep 17 00:00:00 2001 From: Tao Liu Date: Tue, 22 Jun 2021 21:30:26 +0800 Subject: [PATCH] check for invalid physical address of /proc/kcore when finding max_paddr Backport from upstream. commit 38d921a2ef50ebd36258097553626443ffe27496 Author: Coiby Xu Date: Tue Jun 15 18:26:31 2021 +0800 [PATCH] check for invalid physical address of /proc/kcore when finding max_paddr Kernel commit 464920104bf7adac12722035bfefb3d772eb04d8 ("/proc/kcore: update physical address for kcore ram and text") sets an invalid paddr (0xffffffffffffffff = -1) for PT_LOAD segments of not direct mapped regions: $ readelf -l /proc/kcore ... Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flags Align NOTE 0x0000000000000120 0x0000000000000000 0x0000000000000000 0x0000000000002320 0x0000000000000000 0x0 LOAD 0x1000000000010000 0xd000000000000000 0xffffffffffffffff ^^^^^^^^^^^^^^^^^^ 0x0001f80000000000 0x0001f80000000000 RWE 0x10000 makedumpfile uses max_paddr to calculate the number of sections for sparse memory model thus wrong number is obtained based on max_paddr (-1). This error could lead to the failure of copying /proc/kcore for RHEL-8.5 on ppc64le machine [1]: $ makedumpfile /proc/kcore vmcore1 get_mem_section: Could not validate mem_section. get_mm_sparsemem: Can't get the address of mem_section. makedumpfile Failed. Let's check if the phys_start of the segment is a valid physical address to fix this problem. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1965267 Reported-by: Xiaoying Yan Signed-off-by: Coiby Xu Signed-off-by: Tao Liu Acked-by: Kairui Song --- ...ss-proc-kcore-when-finding-max_paddr.patch | 60 +++++++++++++++++++ kexec-tools.spec | 2 + 2 files changed, 62 insertions(+) create mode 100644 kexec-tools-2.0.22-makedumpfile-check-for-invalid-physical-address-proc-kcore-when-finding-max_paddr.patch diff --git a/kexec-tools-2.0.22-makedumpfile-check-for-invalid-physical-address-proc-kcore-when-finding-max_paddr.patch b/kexec-tools-2.0.22-makedumpfile-check-for-invalid-physical-address-proc-kcore-when-finding-max_paddr.patch new file mode 100644 index 0000000..f79ea55 --- /dev/null +++ b/kexec-tools-2.0.22-makedumpfile-check-for-invalid-physical-address-proc-kcore-when-finding-max_paddr.patch @@ -0,0 +1,60 @@ +From 38d921a2ef50ebd36258097553626443ffe27496 Mon Sep 17 00:00:00 2001 +From: Coiby Xu +Date: Tue, 15 Jun 2021 18:26:31 +0800 +Subject: [PATCH] check for invalid physical address of /proc/kcore + when finding max_paddr + +Kernel commit 464920104bf7adac12722035bfefb3d772eb04d8 ("/proc/kcore: +update physical address for kcore ram and text") sets an invalid paddr +(0xffffffffffffffff = -1) for PT_LOAD segments of not direct mapped +regions: + + $ readelf -l /proc/kcore + ... + Program Headers: + Type Offset VirtAddr PhysAddr + FileSiz MemSiz Flags Align + NOTE 0x0000000000000120 0x0000000000000000 0x0000000000000000 + 0x0000000000002320 0x0000000000000000 0x0 + LOAD 0x1000000000010000 0xd000000000000000 0xffffffffffffffff + ^^^^^^^^^^^^^^^^^^ + 0x0001f80000000000 0x0001f80000000000 RWE 0x10000 + +makedumpfile uses max_paddr to calculate the number of sections for +sparse memory model thus wrong number is obtained based on max_paddr +(-1). This error could lead to the failure of copying /proc/kcore +for RHEL-8.5 on ppc64le machine [1]: + + $ makedumpfile /proc/kcore vmcore1 + get_mem_section: Could not validate mem_section. + get_mm_sparsemem: Can't get the address of mem_section. + + makedumpfile Failed. + +Let's check if the phys_start of the segment is a valid physical +address to fix this problem. + +[1] https://bugzilla.redhat.com/show_bug.cgi?id=1965267 + +Reported-by: Xiaoying Yan +Signed-off-by: Coiby Xu +--- + elf_info.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/makedumpfile-1.6.9/elf_info.c b/makedumpfile-1.6.9/elf_info.c +index e8affb7..bc24083 100644 +--- a/makedumpfile-1.6.9/elf_info.c ++++ b/makedumpfile-1.6.9/elf_info.c +@@ -628,7 +628,7 @@ get_max_paddr(void) + + for (i = 0; i < num_pt_loads; i++) { + pls = &pt_loads[i]; +- if (max_paddr < pls->phys_end) ++ if (pls->phys_start != NOT_PADDR && max_paddr < pls->phys_end) + max_paddr = pls->phys_end; + } + return max_paddr; +-- +2.29.2 + diff --git a/kexec-tools.spec b/kexec-tools.spec index ca2e30c..5aeda5a 100644 --- a/kexec-tools.spec +++ b/kexec-tools.spec @@ -101,6 +101,7 @@ Requires: systemd-udev%{?_isa} # Patches 601 onward are generic patches # Patch601: ./kexec-tools-2.0.22-makedumpfile-Increase-SECTION_MAP_LAST_BIT-to-5.patch +Patch602: ./kexec-tools-2.0.22-makedumpfile-check-for-invalid-physical-address-proc-kcore-when-finding-max_paddr.patch %description kexec-tools provides /sbin/kexec binary that facilitates a new @@ -117,6 +118,7 @@ tar -z -x -v -f %{SOURCE9} tar -z -x -v -f %{SOURCE19} %patch601 -p1 +%patch602 -p1 %ifarch ppc %define archdef ARCH=ppc