diff options
Diffstat (limited to '0002-altcall-fix-__alt_call_maybe_initdata-so-it-s-safe-f.patch')
| -rw-r--r-- | 0002-altcall-fix-__alt_call_maybe_initdata-so-it-s-safe-f.patch | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/0002-altcall-fix-__alt_call_maybe_initdata-so-it-s-safe-f.patch b/0002-altcall-fix-__alt_call_maybe_initdata-so-it-s-safe-f.patch new file mode 100644 index 0000000..05ecd83 --- /dev/null +++ b/0002-altcall-fix-__alt_call_maybe_initdata-so-it-s-safe-f.patch @@ -0,0 +1,49 @@ +From 8bdcb0b98b53140102031ceca0611f22190227fd Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= <roger.pau@citrix.com> +Date: Mon, 29 Apr 2024 09:35:21 +0200 +Subject: [PATCH 02/56] altcall: fix __alt_call_maybe_initdata so it's safe for + livepatch +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Setting alternative call variables as __init is not safe for use with +livepatch, as livepatches can rightfully introduce new alternative calls to +structures marked as __alt_call_maybe_initdata (possibly just indirectly due to +replacing existing functions that use those). Attempting to resolve those +alternative calls then results in page faults as the variable that holds the +function pointer address has been freed. + +When livepatch is supported use the __ro_after_init attribute instead of +__initdata for __alt_call_maybe_initdata. + +Fixes: f26bb285949b ('xen: Implement xen/alternative-call.h for use in common code') +Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> +Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> +master commit: af4cd0a6a61cdb03bc1afca9478b05b0c9703599 +master date: 2024-04-11 18:51:36 +0100 +--- + xen/include/xen/alternative-call.h | 7 ++++++- + 1 file changed, 6 insertions(+), 1 deletion(-) + +diff --git a/xen/include/xen/alternative-call.h b/xen/include/xen/alternative-call.h +index 5c6b9a562b..10f7d7637e 100644 +--- a/xen/include/xen/alternative-call.h ++++ b/xen/include/xen/alternative-call.h +@@ -50,7 +50,12 @@ + + #include <asm/alternative.h> + +-#define __alt_call_maybe_initdata __initdata ++#ifdef CONFIG_LIVEPATCH ++/* Must keep for livepatches to resolve alternative calls. */ ++# define __alt_call_maybe_initdata __ro_after_init ++#else ++# define __alt_call_maybe_initdata __initdata ++#endif + + #else + +-- +2.45.2 + |