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author | Tomáš Mózes <tomas.mozes@gmail.com> | 2024-08-01 15:02:58 +0200 |
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committer | Tomáš Mózes <tomas.mozes@gmail.com> | 2024-08-01 15:02:58 +0200 |
commit | 212febf72900c12405591dcc5902d4cfa11173bf (patch) | |
tree | 7a093fae6f723d02b6c4a573669615024fe65e4d /0053-x86-protect-conditional-lock-taking-from-speculative.patch | |
parent | Xen 4.17.4-pre-patchset-1 (diff) | |
download | xen-upstream-patches-212febf72900c12405591dcc5902d4cfa11173bf.tar.gz xen-upstream-patches-212febf72900c12405591dcc5902d4cfa11173bf.tar.bz2 xen-upstream-patches-212febf72900c12405591dcc5902d4cfa11173bf.zip |
Xen 4.18.3-pre-patchset-04.18.3-pre-patchset-0
Signed-off-by: Tomáš Mózes <tomas.mozes@gmail.com>
Diffstat (limited to '0053-x86-protect-conditional-lock-taking-from-speculative.patch')
-rw-r--r-- | 0053-x86-protect-conditional-lock-taking-from-speculative.patch | 216 |
1 files changed, 0 insertions, 216 deletions
diff --git a/0053-x86-protect-conditional-lock-taking-from-speculative.patch b/0053-x86-protect-conditional-lock-taking-from-speculative.patch deleted file mode 100644 index f0caa24..0000000 --- a/0053-x86-protect-conditional-lock-taking-from-speculative.patch +++ /dev/null @@ -1,216 +0,0 @@ -From 0ebd2e49bcd0f566ba6b9158555942aab8e41332 Mon Sep 17 00:00:00 2001 -From: =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= <roger.pau@citrix.com> -Date: Mon, 4 Mar 2024 16:24:21 +0100 -Subject: [PATCH 53/67] x86: protect conditional lock taking from speculative - execution -MIME-Version: 1.0 -Content-Type: text/plain; charset=UTF-8 -Content-Transfer-Encoding: 8bit - -Conditionally taken locks that use the pattern: - -if ( lock ) - spin_lock(...); - -Need an else branch in order to issue an speculation barrier in the else case, -just like it's done in case the lock needs to be acquired. - -eval_nospec() could be used on the condition itself, but that would result in a -double barrier on the branch where the lock is taken. - -Introduce a new pair of helpers, {gfn,spin}_lock_if() that can be used to -conditionally take a lock in a speculation safe way. - -This is part of XSA-453 / CVE-2024-2193 - -Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> -Reviewed-by: Jan Beulich <jbeulich@suse.com> -(cherry picked from commit 03cf7ca23e0e876075954c558485b267b7d02406) ---- - xen/arch/x86/mm.c | 35 +++++++++++++---------------------- - xen/arch/x86/mm/mm-locks.h | 9 +++++++++ - xen/arch/x86/mm/p2m.c | 5 ++--- - xen/include/xen/spinlock.h | 8 ++++++++ - 4 files changed, 32 insertions(+), 25 deletions(-) - -diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c -index 8d19d719bd..d31b8d56ff 100644 ---- a/xen/arch/x86/mm.c -+++ b/xen/arch/x86/mm.c -@@ -5023,8 +5023,7 @@ static l3_pgentry_t *virt_to_xen_l3e(unsigned long v) - if ( !l3t ) - return NULL; - UNMAP_DOMAIN_PAGE(l3t); -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - if ( !(l4e_get_flags(*pl4e) & _PAGE_PRESENT) ) - { - l4_pgentry_t l4e = l4e_from_mfn(l3mfn, __PAGE_HYPERVISOR); -@@ -5061,8 +5060,7 @@ static l2_pgentry_t *virt_to_xen_l2e(unsigned long v) - return NULL; - } - UNMAP_DOMAIN_PAGE(l2t); -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - if ( !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) ) - { - l3e_write(pl3e, l3e_from_mfn(l2mfn, __PAGE_HYPERVISOR)); -@@ -5100,8 +5098,7 @@ l1_pgentry_t *virt_to_xen_l1e(unsigned long v) - return NULL; - } - UNMAP_DOMAIN_PAGE(l1t); -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) - { - l2e_write(pl2e, l2e_from_mfn(l1mfn, __PAGE_HYPERVISOR)); -@@ -5132,6 +5129,8 @@ l1_pgentry_t *virt_to_xen_l1e(unsigned long v) - do { \ - if ( locking ) \ - l3t_lock(page); \ -+ else \ -+ block_lock_speculation(); \ - } while ( false ) - - #define L3T_UNLOCK(page) \ -@@ -5347,8 +5346,7 @@ int map_pages_to_xen( - if ( l3e_get_flags(ol3e) & _PAGE_GLOBAL ) - flush_flags |= FLUSH_TLB_GLOBAL; - -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - if ( (l3e_get_flags(*pl3e) & _PAGE_PRESENT) && - (l3e_get_flags(*pl3e) & _PAGE_PSE) ) - { -@@ -5452,8 +5450,7 @@ int map_pages_to_xen( - if ( l2e_get_flags(*pl2e) & _PAGE_GLOBAL ) - flush_flags |= FLUSH_TLB_GLOBAL; - -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - if ( (l2e_get_flags(*pl2e) & _PAGE_PRESENT) && - (l2e_get_flags(*pl2e) & _PAGE_PSE) ) - { -@@ -5494,8 +5491,7 @@ int map_pages_to_xen( - unsigned long base_mfn; - const l1_pgentry_t *l1t; - -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - - ol2e = *pl2e; - /* -@@ -5549,8 +5545,7 @@ int map_pages_to_xen( - unsigned long base_mfn; - const l2_pgentry_t *l2t; - -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - - ol3e = *pl3e; - /* -@@ -5694,8 +5689,7 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) - l3e_get_flags(*pl3e))); - UNMAP_DOMAIN_PAGE(l2t); - -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - if ( (l3e_get_flags(*pl3e) & _PAGE_PRESENT) && - (l3e_get_flags(*pl3e) & _PAGE_PSE) ) - { -@@ -5754,8 +5748,7 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) - l2e_get_flags(*pl2e) & ~_PAGE_PSE)); - UNMAP_DOMAIN_PAGE(l1t); - -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - if ( (l2e_get_flags(*pl2e) & _PAGE_PRESENT) && - (l2e_get_flags(*pl2e) & _PAGE_PSE) ) - { -@@ -5799,8 +5792,7 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) - */ - if ( (nf & _PAGE_PRESENT) || ((v != e) && (l1_table_offset(v) != 0)) ) - continue; -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - - /* - * L2E may be already cleared, or set to a superpage, by -@@ -5847,8 +5839,7 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf) - if ( (nf & _PAGE_PRESENT) || - ((v != e) && (l2_table_offset(v) + l1_table_offset(v) != 0)) ) - continue; -- if ( locking ) -- spin_lock(&map_pgdir_lock); -+ spin_lock_if(locking, &map_pgdir_lock); - - /* - * L3E may be already cleared, or set to a superpage, by -diff --git a/xen/arch/x86/mm/mm-locks.h b/xen/arch/x86/mm/mm-locks.h -index 265239c49f..3ea2d8eb03 100644 ---- a/xen/arch/x86/mm/mm-locks.h -+++ b/xen/arch/x86/mm/mm-locks.h -@@ -347,6 +347,15 @@ static inline void p2m_unlock(struct p2m_domain *p) - #define p2m_locked_by_me(p) mm_write_locked_by_me(&(p)->lock) - #define gfn_locked_by_me(p,g) p2m_locked_by_me(p) - -+static always_inline void gfn_lock_if(bool condition, struct p2m_domain *p2m, -+ gfn_t gfn, unsigned int order) -+{ -+ if ( condition ) -+ gfn_lock(p2m, gfn, order); -+ else -+ block_lock_speculation(); -+} -+ - /* PoD lock (per-p2m-table) - * - * Protects private PoD data structs: entry and cache -diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c -index b28c899b5e..1fa9e01012 100644 ---- a/xen/arch/x86/mm/p2m.c -+++ b/xen/arch/x86/mm/p2m.c -@@ -292,9 +292,8 @@ mfn_t p2m_get_gfn_type_access(struct p2m_domain *p2m, gfn_t gfn, - if ( q & P2M_UNSHARE ) - q |= P2M_ALLOC; - -- if ( locked ) -- /* Grab the lock here, don't release until put_gfn */ -- gfn_lock(p2m, gfn, 0); -+ /* Grab the lock here, don't release until put_gfn */ -+ gfn_lock_if(locked, p2m, gfn, 0); - - mfn = p2m->get_entry(p2m, gfn, t, a, q, page_order, NULL); - -diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h -index daf48fdea7..7e75d0e2e7 100644 ---- a/xen/include/xen/spinlock.h -+++ b/xen/include/xen/spinlock.h -@@ -216,6 +216,14 @@ static always_inline void spin_lock_irq(spinlock_t *l) - block_lock_speculation(); \ - }) - -+/* Conditionally take a spinlock in a speculation safe way. */ -+static always_inline void spin_lock_if(bool condition, spinlock_t *l) -+{ -+ if ( condition ) -+ _spin_lock(l); -+ block_lock_speculation(); -+} -+ - #define spin_unlock(l) _spin_unlock(l) - #define spin_unlock_irq(l) _spin_unlock_irq(l) - #define spin_unlock_irqrestore(l, f) _spin_unlock_irqrestore(l, f) --- -2.44.0 - |