diff options
Diffstat (limited to '0035-x86-altcall-always-use-a-temporary-parameter-stashin.patch')
| -rw-r--r-- | 0035-x86-altcall-always-use-a-temporary-parameter-stashin.patch | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/0035-x86-altcall-always-use-a-temporary-parameter-stashin.patch b/0035-x86-altcall-always-use-a-temporary-parameter-stashin.patch new file mode 100644 index 0000000..177c73b --- /dev/null +++ b/0035-x86-altcall-always-use-a-temporary-parameter-stashin.patch @@ -0,0 +1,197 @@ +From 2f49d9f89c14519d4cb1e06ab8370cf4ba50fab7 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 12:00:47 +0100 +Subject: [PATCH 35/67] x86/altcall: always use a temporary parameter stashing + variable +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +The usage in ALT_CALL_ARG() on clang of: + +register union { + typeof(arg) e; + const unsigned long r; +} ... + +When `arg` is the first argument to alternative_{,v}call() and +const_vlapic_vcpu() is used results in clang 3.5.0 complaining with: + +arch/x86/hvm/vlapic.c:141:47: error: non-const static data member must be initialized out of line + alternative_call(hvm_funcs.test_pir, const_vlapic_vcpu(vlapic), vec) ) + +Workaround this by pulling `arg1` into a local variable, like it's done for +further arguments (arg2, arg3...) + +Originally arg1 wasn't pulled into a variable because for the a1_ register +local variable the possible clobbering as a result of operators on other +variables don't matter: + +https://gcc.gnu.org/onlinedocs/gcc/Local-Register-Variables.html#Local-Register-Variables + +Note clang version 3.8.1 seems to already be fixed and don't require the +workaround, but since it's harmless do it uniformly everywhere. + +Reported-by: Andrew Cooper <andrew.cooper3@citrix.com> +Fixes: 2ce562b2a413 ('x86/altcall: use a union as register type for function parameters on clang') +Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> +Acked-by: Jan Beulich <jbeulich@suse.com> +master commit: c20850540ad6a32f4fc17bde9b01c92b0df18bf0 +master date: 2024-02-29 08:21:49 +0100 +--- + xen/arch/x86/include/asm/alternative.h | 36 +++++++++++++++++--------- + 1 file changed, 24 insertions(+), 12 deletions(-) + +diff --git a/xen/arch/x86/include/asm/alternative.h b/xen/arch/x86/include/asm/alternative.h +index bcb1dc94f4..fa04481316 100644 +--- a/xen/arch/x86/include/asm/alternative.h ++++ b/xen/arch/x86/include/asm/alternative.h +@@ -253,21 +253,24 @@ extern void alternative_branches(void); + }) + + #define alternative_vcall1(func, arg) ({ \ +- ALT_CALL_ARG(arg, 1); \ ++ typeof(arg) v1_ = (arg); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_NO_ARG2; \ + (void)sizeof(func(arg)); \ + (void)alternative_callN(1, int, func); \ + }) + + #define alternative_call1(func, arg) ({ \ +- ALT_CALL_ARG(arg, 1); \ ++ typeof(arg) v1_ = (arg); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_NO_ARG2; \ + alternative_callN(1, typeof(func(arg)), func); \ + }) + + #define alternative_vcall2(func, arg1, arg2) ({ \ ++ typeof(arg1) v1_ = (arg1); \ + typeof(arg2) v2_ = (arg2); \ +- ALT_CALL_ARG(arg1, 1); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_ARG(v2_, 2); \ + ALT_CALL_NO_ARG3; \ + (void)sizeof(func(arg1, arg2)); \ +@@ -275,17 +278,19 @@ extern void alternative_branches(void); + }) + + #define alternative_call2(func, arg1, arg2) ({ \ ++ typeof(arg1) v1_ = (arg1); \ + typeof(arg2) v2_ = (arg2); \ +- ALT_CALL_ARG(arg1, 1); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_ARG(v2_, 2); \ + ALT_CALL_NO_ARG3; \ + alternative_callN(2, typeof(func(arg1, arg2)), func); \ + }) + + #define alternative_vcall3(func, arg1, arg2, arg3) ({ \ ++ typeof(arg1) v1_ = (arg1); \ + typeof(arg2) v2_ = (arg2); \ + typeof(arg3) v3_ = (arg3); \ +- ALT_CALL_ARG(arg1, 1); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_ARG(v2_, 2); \ + ALT_CALL_ARG(v3_, 3); \ + ALT_CALL_NO_ARG4; \ +@@ -294,9 +299,10 @@ extern void alternative_branches(void); + }) + + #define alternative_call3(func, arg1, arg2, arg3) ({ \ ++ typeof(arg1) v1_ = (arg1); \ + typeof(arg2) v2_ = (arg2); \ + typeof(arg3) v3_ = (arg3); \ +- ALT_CALL_ARG(arg1, 1); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_ARG(v2_, 2); \ + ALT_CALL_ARG(v3_, 3); \ + ALT_CALL_NO_ARG4; \ +@@ -305,10 +311,11 @@ extern void alternative_branches(void); + }) + + #define alternative_vcall4(func, arg1, arg2, arg3, arg4) ({ \ ++ typeof(arg1) v1_ = (arg1); \ + typeof(arg2) v2_ = (arg2); \ + typeof(arg3) v3_ = (arg3); \ + typeof(arg4) v4_ = (arg4); \ +- ALT_CALL_ARG(arg1, 1); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_ARG(v2_, 2); \ + ALT_CALL_ARG(v3_, 3); \ + ALT_CALL_ARG(v4_, 4); \ +@@ -318,10 +325,11 @@ extern void alternative_branches(void); + }) + + #define alternative_call4(func, arg1, arg2, arg3, arg4) ({ \ ++ typeof(arg1) v1_ = (arg1); \ + typeof(arg2) v2_ = (arg2); \ + typeof(arg3) v3_ = (arg3); \ + typeof(arg4) v4_ = (arg4); \ +- ALT_CALL_ARG(arg1, 1); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_ARG(v2_, 2); \ + ALT_CALL_ARG(v3_, 3); \ + ALT_CALL_ARG(v4_, 4); \ +@@ -332,11 +340,12 @@ extern void alternative_branches(void); + }) + + #define alternative_vcall5(func, arg1, arg2, arg3, arg4, arg5) ({ \ ++ typeof(arg1) v1_ = (arg1); \ + typeof(arg2) v2_ = (arg2); \ + typeof(arg3) v3_ = (arg3); \ + typeof(arg4) v4_ = (arg4); \ + typeof(arg5) v5_ = (arg5); \ +- ALT_CALL_ARG(arg1, 1); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_ARG(v2_, 2); \ + ALT_CALL_ARG(v3_, 3); \ + ALT_CALL_ARG(v4_, 4); \ +@@ -347,11 +356,12 @@ extern void alternative_branches(void); + }) + + #define alternative_call5(func, arg1, arg2, arg3, arg4, arg5) ({ \ ++ typeof(arg1) v1_ = (arg1); \ + typeof(arg2) v2_ = (arg2); \ + typeof(arg3) v3_ = (arg3); \ + typeof(arg4) v4_ = (arg4); \ + typeof(arg5) v5_ = (arg5); \ +- ALT_CALL_ARG(arg1, 1); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_ARG(v2_, 2); \ + ALT_CALL_ARG(v3_, 3); \ + ALT_CALL_ARG(v4_, 4); \ +@@ -363,12 +373,13 @@ extern void alternative_branches(void); + }) + + #define alternative_vcall6(func, arg1, arg2, arg3, arg4, arg5, arg6) ({ \ ++ typeof(arg1) v1_ = (arg1); \ + typeof(arg2) v2_ = (arg2); \ + typeof(arg3) v3_ = (arg3); \ + typeof(arg4) v4_ = (arg4); \ + typeof(arg5) v5_ = (arg5); \ + typeof(arg6) v6_ = (arg6); \ +- ALT_CALL_ARG(arg1, 1); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_ARG(v2_, 2); \ + ALT_CALL_ARG(v3_, 3); \ + ALT_CALL_ARG(v4_, 4); \ +@@ -379,12 +390,13 @@ extern void alternative_branches(void); + }) + + #define alternative_call6(func, arg1, arg2, arg3, arg4, arg5, arg6) ({ \ ++ typeof(arg1) v1_ = (arg1); \ + typeof(arg2) v2_ = (arg2); \ + typeof(arg3) v3_ = (arg3); \ + typeof(arg4) v4_ = (arg4); \ + typeof(arg5) v5_ = (arg5); \ + typeof(arg6) v6_ = (arg6); \ +- ALT_CALL_ARG(arg1, 1); \ ++ ALT_CALL_ARG(v1_, 1); \ + ALT_CALL_ARG(v2_, 2); \ + ALT_CALL_ARG(v3_, 3); \ + ALT_CALL_ARG(v4_, 4); \ +-- +2.44.0 + |