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SUSE:SLE-15-SP3:Update
glibc.35625
ulp-prologue-into-asm-functions.patch
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File ulp-prologue-into-asm-functions.patch of Package glibc.35625
From e9b4bbc10e9b9a7346014fe608485bb1aad49f7c Mon Sep 17 00:00:00 2001 From: Giuliano Belinassi <gbelinassi@suse.de> Date: Mon, 6 May 2024 21:06:46 -0300 Subject: [PATCH] Add Userspace Livepatch prologue into ASM functions Userspace Live Patching (ULP) refers to the process of applying patches to the libraries used by a running process, without interrupting it. In order to archive this, functions must have the NOP prologue. This prologue is included automatically when compiled with -fpatchable-function-entry, but for ASM functions this have to be included manually. This patch does this. Signed-off-by: Giuliano Belinassi <gbelinassi@suse.de> --- Makeconfig | 5 +++++ config.h.in | 3 +++ config.make.in | 1 + configure | 20 ++++++++++++++++++++ configure.ac | 13 +++++++++++++ sysdeps/x86/sysdep.h | 24 +++++++++++++++++++----- sysdeps/x86_64/sysdep.h | 40 ++++++++++++++++++++++++++++++++++++++++ 7 files changed, 101 insertions(+), 5 deletions(-) diff --git a/Makeconfig b/Makeconfig index f252842979..1700ae6fb0 100644 --- a/Makeconfig +++ b/Makeconfig @@ -916,6 +916,11 @@ endif # $(+cflags) == "" $(+stack-protector) +gcc-nowarn := -w +# Add flags for Userspace Livepatching support. +ifeq (yes,$(enable-userspace-livepatch)) ++cflags += -fpatchable-function-entry=16,14 +endif + # Each sysdeps directory can contain header files that both will be # used to compile and will be installed. Each can also contain an # include/ subdirectory, whose header files will be used to compile diff --git a/config.h.in b/config.h.in index dea43df438..f379201aec 100644 --- a/config.h.in +++ b/config.h.in @@ -186,6 +186,9 @@ /* Define if the linker defines __ehdr_start. */ #undef HAVE_EHDR_START +/* Define to 1 if support for userspace livepatching is enabled. */ +#define ENABLE_USERSPACE_LIVEPATCH 0 + /* */ diff --git a/config.make.in b/config.make.in index 2fed3da773..1ed8bcc786 100644 --- a/config.make.in +++ b/config.make.in @@ -88,6 +88,7 @@ nss-crypt = @libc_cv_nss_crypt@ static-nss-crypt = @libc_cv_static_nss_crypt@ # Configuration options. +enable-userspace-livepatch = @enable_userspace_livepatch@ build-shared = @shared@ build-pic-default= @libc_cv_pic_default@ build-pie-default= @libc_cv_pie_default@ diff --git a/configure b/configure index 3b98ec312f..95de3f637f 100755 --- a/configure +++ b/configure @@ -590,6 +590,7 @@ ac_subst_vars='LTLIBOBJS LIBOBJS RELEASE VERSION +enable_userspace_livepatch mach_interface_list DEFINES static_nss @@ -795,6 +796,7 @@ enable_tunables enable_mathvec enable_cet with_cpu +enable_userspace_livepatch ' ac_precious_vars='build_alias host_alias @@ -1471,6 +1473,8 @@ Optional Features: depends on architecture] --enable-cet enable Intel Control-flow Enforcement Technology (CET), x86 only + --enable-userspace-livepatch + build with userspace livepatch support [default=no] Optional Packages: --with-PACKAGE[=ARG] use PACKAGE [ARG=yes] @@ -6918,6 +6922,22 @@ enable-static-pie = $static_pie" +# Check whether --enable-userspace-livepatch was given. +if test "${enable_userspace_livepatch+set}" = set; then : + enableval=$enable_userspace_livepatch; enable_userspace_livepatch=$enableval +else + enable_userspace_livepatch=no +fi + + +# Libpulp uses -fpatchable-function-entry to add padding NOPS to the +# prologue of all functions. +if test "x$enable_userspace_livepatch" = xyes; then + $as_echo "#define ENABLE_USERSPACE_LIVEPATCH 1" >>confdefs.h + +fi + + VERSION=`sed -n -e 's/^#define VERSION "\([^"]*\)"/\1/p' < $srcdir/version.h` RELEASE=`sed -n -e 's/^#define RELEASE "\([^"]*\)"/\1/p' < $srcdir/version.h` diff --git a/configure.ac b/configure.ac index e20034f301..a9bcf62681 100644 --- a/configure.ac +++ b/configure.ac @@ -1896,6 +1896,19 @@ AC_SUBST(DEFINES) dnl See sysdeps/mach/configure.ac for this variable. AC_SUBST(mach_interface_list) +AC_ARG_ENABLE([userspace-livepatch], + AS_HELP_STRING([--enable-userspace-livepatch], + [build with userspace livepatch support @<:@default=no@:>@]), + [enable_userspace_livepatch=$enableval], + [enable_userspace_livepatch=no]) + +# Libpulp uses -fpatchable-function-entry to add padding NOPS to the +# prologue of all functions. +if test "x$enable_userspace_livepatch" = xyes; then + AC_DEFINE(ENABLE_USERSPACE_LIVEPATCH) +fi +AC_SUBST(enable_userspace_livepatch) + VERSION=`sed -n -e 's/^#define VERSION "\([^"]*\)"/\1/p' < $srcdir/version.h` RELEASE=`sed -n -e 's/^#define RELEASE "\([^"]*\)"/\1/p' < $srcdir/version.h` AC_SUBST(VERSION) diff --git a/sysdeps/x86/sysdep.h b/sysdeps/x86/sysdep.h index f5039bc1b2..e399aa18e9 100644 --- a/sysdeps/x86/sysdep.h +++ b/sysdeps/x86/sysdep.h @@ -72,15 +72,29 @@ enum cf_protection_level #define ALIGNARG(log2) 1<<log2 #define ASM_SIZE_DIRECTIVE(name) .size name,.-name; +/* For 32-bit glibc then define those macros as empty. */ +#ifndef ULP_PRE_PROLOGUE +# define ULP_PRE_PROLOGUE(name) +#endif +#ifndef ULP_POST_PROLOGUE +# define ULP_POST_PROLOGUE(name) +#endif + +/* Define the first instructions of a function. */ +#define FUNCTION_START(name) \ + ULP_PRE_PROLOGUE(name); \ + C_LABEL(name); \ + cfi_startproc; \ + _CET_ENDBR; \ + ULP_POST_PROLOGUE(name); \ + CALL_MCOUNT; + /* Define an entry point visible from C. */ #define ENTRY(name) \ .globl C_SYMBOL_NAME(name); \ .type C_SYMBOL_NAME(name),@function; \ - .align ALIGNARG(4); \ - C_LABEL(name) \ - cfi_startproc; \ - _CET_ENDBR; \ - CALL_MCOUNT + .align ALIGNARG(4); \ + FUNCTION_START(name) #undef END #define END(name) \ diff --git a/sysdeps/x86_64/sysdep.h b/sysdeps/x86_64/sysdep.h index c8ad778fee..59c278eb58 100644 --- a/sysdeps/x86_64/sysdep.h +++ b/sysdeps/x86_64/sysdep.h @@ -23,6 +23,46 @@ #ifdef __ASSEMBLER__ +/* Libpulp uses -fpatchable-function-entry to add padding NOPS to the + prologue of all functions. This works for C functions. For functions + written in ASM, the way we do this is by adding this prologue manually. */ + +#if ENABLE_USERSPACE_LIVEPATCH + +/* Instructions to be inserted before the function label. */ +# define ULP_NOPS_PRE_PROLOGUE .rept 14; nop; .endr + +/* Instruction to be inserted after the function label. */ +# define ULP_NOPS_POST_PROLOGUE .rept 2; nop; .endr + + +/* this macro expands according to the following condition: + * if name = _start, then the prologue is not inserted. + * if name = _dl_relocate_static_pie, then the prologue is not inserted. + * if name = anything else, then the prologue is inserted. + **/ +# define __ULP_POST_PROLOGUE_dl_relocate_static_pie , +# define __ULP_PRE_PROLOGUE_start , +# define __ULP_PRE_PROLOGUE(x, y,...) y +# define _ULP_PRE_PROLOGUE(x, ...) __ULP_PRE_PROLOGUE(x, __VA_ARGS__) +# define ULP_PRE_PROLOGUE(name) _ULP_PRE_PROLOGUE(__ULP_PRE_PROLOGUE##name, ULP_NOPS_PRE_PROLOGUE,) + +/* this macro expands according to the following condition: + * if name = _start, then the postlogue is not inserted. + * if name = _dl_relocate_static_pie, then the postlogue is not inserted. + * if name = anything else, then the postlogue is inserted. + **/ +# define __ULP_POST_PROLOGUE_dl_relocate_static_pie , +# define __ULP_POST_PROLOGUE_start , +# define __ULP_POST_PROLOGUE(x, y,...) y +# define _ULP_POST_PROLOGUE(x, ...) __ULP_POST_PROLOGUE(x, __VA_ARGS__) +# define ULP_POST_PROLOGUE(name) _ULP_POST_PROLOGUE(__ULP_POST_PROLOGUE##name, ULP_NOPS_POST_PROLOGUE,) + +#else +# define ULP_PRE_PROLOGUE(name) +# define ULP_POST_PROLOGUE(name) +#endif + /* Syntactic details of assembler. */ /* This macro is for setting proper CFI with DW_CFA_expression describing -- 2.44.0
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