From: Jan Beulich <jbeulich@suse.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
"Wei Liu" <wl@xen.org>, "Roger Pau Monné" <roger.pau@citrix.com>,
"Tim Deegan" <tim@xen.org>,
"George Dunlap" <george.dunlap@citrix.com>,
"Elena Ufimtseva" <elena.ufimtseva@oracle.com>
Subject: [PATCH 06/17] x86/gdbsx: convert "user" to "guest" accesses
Date: Thu, 14 Jan 2021 16:05:57 +0100 [thread overview]
Message-ID: <0ba3d730-8bc6-0907-8e60-ce3176afa491@suse.com> (raw)
In-Reply-To: <4f1975a9-bdd9-f556-9db5-eb6c428f258f@suse.com>
Using copy_{from,to}_user(), this code was assuming to be called only by
PV guests. Use copy_{from,to}_guest() instead, transforming the incoming
structure field into a guest handle (the field should really have been
one in the first place). Also do not transform the debuggee address into
a pointer.
As a not originally intended side effect this also fixes a bug in
dbg_rw_guest_mem(): At the end of the loop "addr" was incremented, but
then in the next loop iteration (with the variable also having gone out
of scope inbetween) re-initialized from the function parameter.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/arch/x86/debug.c
+++ b/xen/arch/x86/debug.c
@@ -108,14 +108,14 @@ dbg_pv_va2mfn(dbgva_t vaddr, struct doma
}
/* Returns: number of bytes remaining to be copied */
-static unsigned int dbg_rw_guest_mem(struct domain *dp, void * __user gaddr,
- void * __user buf, unsigned int len,
- bool toaddr, uint64_t pgd3)
+static unsigned int dbg_rw_guest_mem(struct domain *dp, unsigned long addr,
+ XEN_GUEST_HANDLE_PARAM(void) buf,
+ unsigned int len, bool toaddr,
+ uint64_t pgd3)
{
while ( len > 0 )
{
char *va;
- unsigned long addr = (unsigned long)gaddr;
mfn_t mfn;
gfn_t gfn = INVALID_GFN;
unsigned long pagecnt;
@@ -133,20 +133,18 @@ static unsigned int dbg_rw_guest_mem(str
if ( toaddr )
{
- copy_from_user(va, buf, pagecnt); /* va = buf */
+ copy_from_guest(va, buf, pagecnt);
paging_mark_dirty(dp, mfn);
}
else
- {
- copy_to_user(buf, va, pagecnt); /* buf = va */
- }
+ copy_to_guest(buf, va, pagecnt);
unmap_domain_page(va);
if ( !gfn_eq(gfn, INVALID_GFN) )
put_gfn(dp, gfn_x(gfn));
addr += pagecnt;
- buf += pagecnt;
+ guest_handle_add_offset(buf, pagecnt);
len -= pagecnt;
}
@@ -160,7 +158,7 @@ static unsigned int dbg_rw_guest_mem(str
* pgd3: value of init_mm.pgd[3] in guest. see above.
* Returns: number of bytes remaining to be copied.
*/
-unsigned int dbg_rw_mem(void * __user addr, void * __user buf,
+unsigned int dbg_rw_mem(unsigned long gva, XEN_GUEST_HANDLE_PARAM(void) buf,
unsigned int len, domid_t domid, bool toaddr,
uint64_t pgd3)
{
@@ -169,7 +167,7 @@ unsigned int dbg_rw_mem(void * __user ad
if ( d )
{
if ( !d->is_dying )
- len = dbg_rw_guest_mem(d, addr, buf, len, toaddr, pgd3);
+ len = dbg_rw_guest_mem(d, gva, buf, len, toaddr, pgd3);
rcu_unlock_domain(d);
}
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -40,10 +40,8 @@
#ifdef CONFIG_GDBSX
static int gdbsx_guest_mem_io(domid_t domid, struct xen_domctl_gdbsx_memio *iop)
{
- void * __user gva = (void *)iop->gva, * __user uva = (void *)iop->uva;
-
- iop->remain = dbg_rw_mem(gva, uva, iop->len, domid,
- !!iop->gwr, iop->pgd3val);
+ iop->remain = dbg_rw_mem(iop->gva, guest_handle_from_ptr(iop->uva, void),
+ iop->len, domid, iop->gwr, iop->pgd3val);
return iop->remain ? -EFAULT : 0;
}
--- a/xen/include/asm-x86/debugger.h
+++ b/xen/include/asm-x86/debugger.h
@@ -93,9 +93,9 @@ static inline bool debugger_trap_entry(
#endif
#ifdef CONFIG_GDBSX
-unsigned int dbg_rw_mem(void * __user addr, void * __user buf,
+unsigned int dbg_rw_mem(unsigned long gva, XEN_GUEST_HANDLE_PARAM(void) buf,
unsigned int len, domid_t domid, bool toaddr,
- uint64_t pgd3);
+ unsigned long pgd3);
#endif
#endif /* __X86_DEBUGGER_H__ */
next prev parent reply other threads:[~2021-01-14 15:06 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-14 15:01 [PATCH 00/17] x86/PV: avoid speculation abuse through guest accessors plus Jan Beulich
2021-01-14 15:03 ` [PATCH 01/17] x86/shadow: use __put_user() instead of __copy_to_user() Jan Beulich
2021-01-14 15:04 ` [PATCH 02/17] x86: split __{get,put}_user() into "guest" and "unsafe" variants Jan Beulich
2021-02-05 15:43 ` Roger Pau Monné
2021-02-05 16:13 ` Jan Beulich
2021-02-05 16:18 ` Roger Pau Monné
2021-02-05 16:26 ` Jan Beulich
2021-02-09 13:07 ` Roger Pau Monné
2021-02-09 13:15 ` Jan Beulich
2021-02-09 14:46 ` Roger Pau Monné
2021-02-09 14:57 ` Jan Beulich
2021-02-09 15:23 ` Roger Pau Monné
2021-02-09 14:55 ` Roger Pau Monné
2021-02-09 15:14 ` Jan Beulich
2021-02-09 15:27 ` Roger Pau Monné
2021-01-14 15:04 ` [PATCH 03/17] x86: split __copy_{from,to}_user() " Jan Beulich
2021-02-09 16:06 ` Roger Pau Monné
2021-02-09 17:03 ` Jan Beulich
2021-01-14 15:04 ` [PATCH 04/17] x86/PV: harden guest memory accesses against speculative abuse Jan Beulich
2021-02-09 16:26 ` Roger Pau Monné
2021-02-10 16:55 ` Jan Beulich
2021-02-11 8:11 ` Roger Pau Monné
2021-02-11 11:28 ` Jan Beulich
2021-02-12 10:41 ` Roger Pau Monné
2021-02-12 12:48 ` Jan Beulich
2021-02-12 13:02 ` Roger Pau Monné
2021-02-12 13:15 ` Jan Beulich
2021-01-14 15:05 ` [PATCH 05/17] x86: rename {get,put}_user() to {get,put}_guest() Jan Beulich
2021-01-14 15:05 ` Jan Beulich [this message]
2021-01-14 15:06 ` [PATCH 07/17] x86: rename copy_{from,to}_user() to copy_{from,to}_guest_pv() Jan Beulich
2021-01-14 15:07 ` [PATCH 08/17] x86: move stac()/clac() from {get,put}_unsafe_asm() Jan Beulich
2021-01-14 15:07 ` [PATCH 09/17] x86/PV: use get_unsafe() instead of copy_from_unsafe() Jan Beulich
2021-01-14 15:08 ` [PATCH 10/17] x86/shadow: " Jan Beulich
2021-01-14 15:08 ` [PATCH 11/17] x86/shadow: polish shadow_write_entries() Jan Beulich
2021-01-14 15:09 ` [PATCH 12/17] x86/shadow: move shadow_set_l<N>e() to their own source file Jan Beulich
2021-01-14 15:09 ` [PATCH 13/17] x86/shadow: don't open-code SHF_* shorthands Jan Beulich
2021-01-14 15:10 ` [PATCH 14/17] x86/shadow: SH_type_l2h_shadow is PV-only Jan Beulich
2021-01-14 15:10 ` [PATCH 15/17] x86/shadow: drop SH_type_l2h_pae_shadow Jan Beulich
2021-01-22 13:11 ` Tim Deegan
2021-01-22 16:31 ` Jan Beulich
2021-01-22 20:02 ` Tim Deegan
2021-01-25 11:09 ` Jan Beulich
2021-01-25 11:33 ` Jan Beulich
2021-01-14 15:10 ` [PATCH 16/17] x86/shadow: only 4-level guest code needs building when !HVM Jan Beulich
2021-01-14 15:11 ` [PATCH 17/17] x86/shadow: adjust is_pv_*() checks Jan Beulich
2021-01-22 13:18 ` [PATCH 00/17] x86/PV: avoid speculation abuse through guest accessors plus Tim Deegan
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