git: 3ce04aca49e9 - main - proc: Add a sysctl to fetch virtual address space layout info
Date: Mon, 17 Jan 2022 21:13:10 UTC
The branch main has been updated by markj:
URL: https://cgit.FreeBSD.org/src/commit/?id=3ce04aca49e9228c3c6ab24ffbee709f5b464765
commit 3ce04aca49e9228c3c6ab24ffbee709f5b464765
Author: Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2022-01-17 16:43:03 +0000
Commit: Mark Johnston <markj@FreeBSD.org>
CommitDate: 2022-01-17 21:12:43 +0000
proc: Add a sysctl to fetch virtual address space layout info
This provides information about fixed regions of the target process'
user memory map.
Reviewed by: kib
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33708
---
sys/compat/freebsd32/freebsd32.h | 13 +++++++
sys/kern/kern_proc.c | 78 ++++++++++++++++++++++++++++++++++++++++
sys/sys/sysctl.h | 1 +
sys/sys/user.h | 19 ++++++++++
4 files changed, 111 insertions(+)
diff --git a/sys/compat/freebsd32/freebsd32.h b/sys/compat/freebsd32/freebsd32.h
index 1f6270d684ee..96bf79d28c02 100644
--- a/sys/compat/freebsd32/freebsd32.h
+++ b/sys/compat/freebsd32/freebsd32.h
@@ -432,6 +432,19 @@ struct kinfo_sigtramp32 {
uint32_t ksigtramp_spare[4];
};
+struct kinfo_vm_layout32 {
+ uint32_t kvm_min_user_addr;
+ uint32_t kvm_max_user_addr;
+ uint32_t kvm_text_addr;
+ uint32_t kvm_text_size;
+ uint32_t kvm_data_addr;
+ uint32_t kvm_data_size;
+ uint32_t kvm_stack_addr;
+ uint32_t kvm_stack_size;
+ int kvm_map_flags;
+ uint32_t kvm_spare[14];
+};
+
struct kld_file_stat_1_32 {
int version; /* set to sizeof(struct kld_file_stat_1) */
char name[MAXPATHLEN];
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index 1ef8d86295b3..b5896cedf3b9 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -3200,6 +3200,80 @@ errlocked:
return (error);
}
+static int
+sysctl_kern_proc_vm_layout(SYSCTL_HANDLER_ARGS)
+{
+ struct kinfo_vm_layout kvm;
+ struct proc *p;
+ struct vmspace *vmspace;
+ int error, *name;
+
+ name = (int *)arg1;
+ if ((u_int)arg2 != 1)
+ return (EINVAL);
+
+ error = pget((pid_t)name[0], PGET_CANDEBUG, &p);
+ if (error != 0)
+ return (error);
+#ifdef COMPAT_FREEBSD32
+ if (SV_CURPROC_FLAG(SV_ILP32)) {
+ if (!SV_PROC_FLAG(p, SV_ILP32)) {
+ PROC_UNLOCK(p);
+ return (EINVAL);
+ }
+ }
+#endif
+ vmspace = vmspace_acquire_ref(p);
+ PROC_UNLOCK(p);
+
+ memset(&kvm, 0, sizeof(kvm));
+ kvm.kvm_min_user_addr = vm_map_min(&vmspace->vm_map);
+ kvm.kvm_max_user_addr = vm_map_max(&vmspace->vm_map);
+ kvm.kvm_text_addr = (uintptr_t)vmspace->vm_taddr;
+ kvm.kvm_text_size = vmspace->vm_tsize;
+ kvm.kvm_data_addr = (uintptr_t)vmspace->vm_daddr;
+ kvm.kvm_data_size = vmspace->vm_dsize;
+ kvm.kvm_stack_addr = (uintptr_t)vmspace->vm_maxsaddr;
+ kvm.kvm_stack_size = vmspace->vm_ssize;
+ if ((vmspace->vm_map.flags & MAP_WIREFUTURE) != 0)
+ kvm.kvm_map_flags |= KMAP_FLAG_WIREFUTURE;
+ if ((vmspace->vm_map.flags & MAP_ASLR) != 0)
+ kvm.kvm_map_flags |= KMAP_FLAG_ASLR;
+ if ((vmspace->vm_map.flags & MAP_ASLR_IGNSTART) != 0)
+ kvm.kvm_map_flags |= KMAP_FLAG_ASLR_IGNSTART;
+ if ((vmspace->vm_map.flags & MAP_WXORX) != 0)
+ kvm.kvm_map_flags |= KMAP_FLAG_WXORX;
+ if ((vmspace->vm_map.flags & MAP_ASLR_STACK) != 0)
+ kvm.kvm_map_flags |= KMAP_FLAG_ASLR_STACK;
+
+#ifdef COMPAT_FREEBSD32
+ if (SV_CURPROC_FLAG(SV_ILP32)) {
+ struct kinfo_vm_layout32 kvm32;
+
+ memset(&kvm32, 0, sizeof(kvm32));
+ kvm32.kvm_min_user_addr = (uint32_t)kvm.kvm_min_user_addr;
+ kvm32.kvm_max_user_addr = (uint32_t)kvm.kvm_max_user_addr;
+ kvm32.kvm_text_addr = (uint32_t)kvm.kvm_text_addr;
+ kvm32.kvm_text_size = (uint32_t)kvm.kvm_text_size;
+ kvm32.kvm_data_addr = (uint32_t)kvm.kvm_data_addr;
+ kvm32.kvm_data_size = (uint32_t)kvm.kvm_data_size;
+ kvm32.kvm_stack_addr = (uint32_t)kvm.kvm_stack_addr;
+ kvm32.kvm_stack_size = (uint32_t)kvm.kvm_stack_size;
+ kvm32.kvm_map_flags = kvm.kvm_map_flags;
+ vmspace_free(vmspace);
+ error = SYSCTL_OUT(req, &kvm32, sizeof(kvm32));
+ goto out;
+ }
+#endif
+
+ error = SYSCTL_OUT(req, &kvm, sizeof(kvm));
+#ifdef COMPAT_FREEBSD32
+out:
+#endif
+ vmspace_free(vmspace);
+ return (error);
+}
+
SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
"Process table");
@@ -3318,6 +3392,10 @@ static SYSCTL_NODE(_kern_proc, KERN_PROC_SIGFASTBLK, sigfastblk, CTLFLAG_RD |
CTLFLAG_ANYBODY | CTLFLAG_MPSAFE, sysctl_kern_proc_sigfastblk,
"Thread sigfastblock address");
+static SYSCTL_NODE(_kern_proc, KERN_PROC_VM_LAYOUT, vm_layout, CTLFLAG_RD |
+ CTLFLAG_ANYBODY | CTLFLAG_MPSAFE, sysctl_kern_proc_vm_layout,
+ "Process virtual address space layout info");
+
int allproc_gen;
/*
diff --git a/sys/sys/sysctl.h b/sys/sys/sysctl.h
index 71a34652ff44..f25152db8215 100644
--- a/sys/sys/sysctl.h
+++ b/sys/sys/sysctl.h
@@ -1013,6 +1013,7 @@ TAILQ_HEAD(sysctl_ctx_list, sysctl_ctx_entry);
#define KERN_PROC_CWD 42 /* process current working directory */
#define KERN_PROC_NFDS 43 /* number of open file descriptors */
#define KERN_PROC_SIGFASTBLK 44 /* address of fastsigblk magic word */
+#define KERN_PROC_VM_LAYOUT 45 /* virtual address space layout info */
/*
* KERN_IPC identifiers
diff --git a/sys/sys/user.h b/sys/sys/user.h
index e8bfba981e83..f57a69aed13e 100644
--- a/sys/sys/user.h
+++ b/sys/sys/user.h
@@ -598,6 +598,25 @@ struct kinfo_sigtramp {
void *ksigtramp_spare[4];
};
+#define KMAP_FLAG_WIREFUTURE 0x01 /* all future mappings wil be wired */
+#define KMAP_FLAG_ASLR 0x02 /* ASLR is applied to mappings */
+#define KMAP_FLAG_ASLR_IGNSTART 0x04 /* ASLR may map into sbrk grow region */
+#define KMAP_FLAG_WXORX 0x08 /* W^X mapping policy is enforced */
+#define KMAP_FLAG_ASLR_STACK 0x10 /* the stack location is randomized */
+
+struct kinfo_vm_layout {
+ uintptr_t kvm_min_user_addr;
+ uintptr_t kvm_max_user_addr;
+ uintptr_t kvm_text_addr;
+ size_t kvm_text_size;
+ uintptr_t kvm_data_addr;
+ size_t kvm_data_size;
+ uintptr_t kvm_stack_addr;
+ size_t kvm_stack_size;
+ int kvm_map_flags;
+ uintptr_t kvm_spare[14];
+};
+
#ifdef _KERNEL
/* Flags for kern_proc_out function. */
#define KERN_PROC_NOTHREADS 0x1