71 lines
2.5 KiB
Diff
71 lines
2.5 KiB
Diff
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From 1cebb3d75b45fedc734dac8563782a3e6d86f23b Mon Sep 17 00:00:00 2001
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From: Lianbo Jiang <lijiang@redhat.com>
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Date: Thu, 23 Mar 2023 13:18:07 +0800
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Subject: [PATCH 85/89] Fix "vm -M" option to properly deal with an invalid
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argument
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The "vm -M" option can accept an invalid address and print the virtual
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memory data of a task without an error like this:
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crash> vm -M 0xdeadbeef
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PID: 92960 TASK: ffff99157976cc80 CPU: 0 COMMAND: "crash"
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MM PGD RSS TOTAL_VM
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ffff991573bfdf00 ffff9915857f2000 449020k 2427076k
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VMA START END FLAGS FILE
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ffff99158718d1c8 400000 4de000 8000071 /home/crash/crash
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...
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The reasons are
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- htoll() only converts a hexadecimal string to an unsigned long long
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value and does not evaluate whether it's a valid kernel virtual
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address or not, and
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- The specified value is used only when the task's mm_struct is NULL.
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Also, this behavior is not described enough in its help text, so it's
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confusing for users.
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Let's add a check on the converted value regardless of the task's
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mm_struct and add a description of the behavior to its help text.
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With the patch:
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crash> vm -M 0xdeadbeef
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vm: invalid mm_struct address: 0xdeadbeef
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Reported-by: Buland Kumar Singh <bsingh@redhat.com>
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Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
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[ kh: rewrote commit message ]
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Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
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---
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help.c | 1 +
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memory.c | 2 ++
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2 files changed, 3 insertions(+)
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diff --git a/help.c b/help.c
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index 7ceefa06732b..738bbca2e563 100644
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--- a/help.c
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+++ b/help.c
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@@ -4701,6 +4701,7 @@ char *help_vm[] = {
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" However, if the address can be determined from the kernel stack,",
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" it can be entered manually in order to try to resurrect the",
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" virtual memory data of the task.",
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+" NOTE: this option is only used when the task's mm_struct is NULL.",
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" -R reference search for references to this number or filename.",
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" -m dump the mm_struct associated with the task.",
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" -v dump all of the vm_area_structs associated with the task.",
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diff --git a/memory.c b/memory.c
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index 592a5ef49d50..0568f18eb9b7 100644
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--- a/memory.c
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+++ b/memory.c
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@@ -3559,6 +3559,8 @@ cmd_vm(void)
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case 'M':
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pc->curcmd_private = htoll(optarg, FAULT_ON_ERROR, NULL);
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pc->curcmd_flags |= MM_STRUCT_FORCE;
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+ if (!IS_KVADDR(pc->curcmd_private))
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+ error(FATAL, "invalid mm_struct address: %s\n", optarg);
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break;
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case 'f':
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--
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2.37.1
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