diff options
Diffstat (limited to '0032-xen-livepatch-fix-norevert-test-attempt-to-open-code.patch')
| -rw-r--r-- | 0032-xen-livepatch-fix-norevert-test-attempt-to-open-code.patch | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/0032-xen-livepatch-fix-norevert-test-attempt-to-open-code.patch b/0032-xen-livepatch-fix-norevert-test-attempt-to-open-code.patch new file mode 100644 index 0000000..76af9ef --- /dev/null +++ b/0032-xen-livepatch-fix-norevert-test-attempt-to-open-code.patch @@ -0,0 +1,186 @@ +From 5564323f643715f9d364df88e0eb9c7d6fd2c22b Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= <roger.pau@citrix.com> +Date: Tue, 5 Mar 2024 11:59:43 +0100 +Subject: [PATCH 32/67] xen/livepatch: fix norevert test attempt to open-code + revert +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +The purpose of the norevert test is to install a dummy handler that replaces +the internal Xen revert code, and then perform the revert in the post-revert +hook. For that purpose the usage of the previous common_livepatch_revert() is +not enough, as that just reverts specific functions, but not the whole state of +the payload. + +Remove both common_livepatch_{apply,revert}() and instead expose +revert_payload{,_tail}() in order to perform the patch revert from the +post-revert hook. + +Fixes: 6047104c3ccc ('livepatch: Add per-function applied/reverted state tracking marker') +Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> +Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com> +master commit: cdae267ce10d04d71d1687b5701ff2911a96b6dc +master date: 2024-02-28 16:57:25 +0000 +--- + xen/common/livepatch.c | 41 +++++++++++++++++-- + xen/include/xen/livepatch.h | 32 ++------------- + .../livepatch/xen_action_hooks_norevert.c | 22 +++------- + 3 files changed, 46 insertions(+), 49 deletions(-) + +diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c +index a129ab9973..a5068a2217 100644 +--- a/xen/common/livepatch.c ++++ b/xen/common/livepatch.c +@@ -1310,7 +1310,22 @@ static int apply_payload(struct payload *data) + ASSERT(!local_irq_is_enabled()); + + for ( i = 0; i < data->nfuncs; i++ ) +- common_livepatch_apply(&data->funcs[i], &data->fstate[i]); ++ { ++ const struct livepatch_func *func = &data->funcs[i]; ++ struct livepatch_fstate *state = &data->fstate[i]; ++ ++ /* If the action has been already executed on this function, do nothing. */ ++ if ( state->applied == LIVEPATCH_FUNC_APPLIED ) ++ { ++ printk(XENLOG_WARNING LIVEPATCH ++ "%s: %s has been already applied before\n", ++ __func__, func->name); ++ continue; ++ } ++ ++ arch_livepatch_apply(func, state); ++ state->applied = LIVEPATCH_FUNC_APPLIED; ++ } + + arch_livepatch_revive(); + +@@ -1326,7 +1341,7 @@ static inline void apply_payload_tail(struct payload *data) + data->state = LIVEPATCH_STATE_APPLIED; + } + +-static int revert_payload(struct payload *data) ++int revert_payload(struct payload *data) + { + unsigned int i; + int rc; +@@ -1341,7 +1356,25 @@ static int revert_payload(struct payload *data) + } + + for ( i = 0; i < data->nfuncs; i++ ) +- common_livepatch_revert(&data->funcs[i], &data->fstate[i]); ++ { ++ const struct livepatch_func *func = &data->funcs[i]; ++ struct livepatch_fstate *state = &data->fstate[i]; ++ ++ /* ++ * If the apply action hasn't been executed on this function, do ++ * nothing. ++ */ ++ if ( !func->old_addr || state->applied == LIVEPATCH_FUNC_NOT_APPLIED ) ++ { ++ printk(XENLOG_WARNING LIVEPATCH ++ "%s: %s has not been applied before\n", ++ __func__, func->name); ++ continue; ++ } ++ ++ arch_livepatch_revert(func, state); ++ state->applied = LIVEPATCH_FUNC_NOT_APPLIED; ++ } + + /* + * Since we are running with IRQs disabled and the hooks may call common +@@ -1359,7 +1392,7 @@ static int revert_payload(struct payload *data) + return 0; + } + +-static inline void revert_payload_tail(struct payload *data) ++void revert_payload_tail(struct payload *data) + { + list_del(&data->applied_list); + +diff --git a/xen/include/xen/livepatch.h b/xen/include/xen/livepatch.h +index 537d3d58b6..c9ee58fd37 100644 +--- a/xen/include/xen/livepatch.h ++++ b/xen/include/xen/livepatch.h +@@ -136,35 +136,11 @@ void arch_livepatch_post_action(void); + void arch_livepatch_mask(void); + void arch_livepatch_unmask(void); + +-static inline void common_livepatch_apply(const struct livepatch_func *func, +- struct livepatch_fstate *state) +-{ +- /* If the action has been already executed on this function, do nothing. */ +- if ( state->applied == LIVEPATCH_FUNC_APPLIED ) +- { +- printk(XENLOG_WARNING LIVEPATCH "%s: %s has been already applied before\n", +- __func__, func->name); +- return; +- } +- +- arch_livepatch_apply(func, state); +- state->applied = LIVEPATCH_FUNC_APPLIED; +-} ++/* Only for testing purposes. */ ++struct payload; ++int revert_payload(struct payload *data); ++void revert_payload_tail(struct payload *data); + +-static inline void common_livepatch_revert(const struct livepatch_func *func, +- struct livepatch_fstate *state) +-{ +- /* If the apply action hasn't been executed on this function, do nothing. */ +- if ( !func->old_addr || state->applied == LIVEPATCH_FUNC_NOT_APPLIED ) +- { +- printk(XENLOG_WARNING LIVEPATCH "%s: %s has not been applied before\n", +- __func__, func->name); +- return; +- } +- +- arch_livepatch_revert(func, state); +- state->applied = LIVEPATCH_FUNC_NOT_APPLIED; +-} + #else + + /* +diff --git a/xen/test/livepatch/xen_action_hooks_norevert.c b/xen/test/livepatch/xen_action_hooks_norevert.c +index c173855192..c5fbab1746 100644 +--- a/xen/test/livepatch/xen_action_hooks_norevert.c ++++ b/xen/test/livepatch/xen_action_hooks_norevert.c +@@ -96,26 +96,14 @@ static int revert_hook(livepatch_payload_t *payload) + + static void post_revert_hook(livepatch_payload_t *payload) + { +- int i; ++ unsigned long flags; + + printk(KERN_DEBUG "%s: Hook starting.\n", __func__); + +- for (i = 0; i < payload->nfuncs; i++) +- { +- const struct livepatch_func *func = &payload->funcs[i]; +- struct livepatch_fstate *fstate = &payload->fstate[i]; +- +- BUG_ON(revert_cnt != 1); +- BUG_ON(fstate->applied != LIVEPATCH_FUNC_APPLIED); +- +- /* Outside of quiesce zone: MAY TRIGGER HOST CRASH/UNDEFINED BEHAVIOR */ +- arch_livepatch_quiesce(); +- common_livepatch_revert(payload); +- arch_livepatch_revive(); +- BUG_ON(fstate->applied == LIVEPATCH_FUNC_APPLIED); +- +- printk(KERN_DEBUG "%s: post reverted: %s\n", __func__, func->name); +- } ++ local_irq_save(flags); ++ BUG_ON(revert_payload(payload)); ++ revert_payload_tail(payload); ++ local_irq_restore(flags); + + printk(KERN_DEBUG "%s: Hook done.\n", __func__); + } +-- +2.44.0 + |