summaryrefslogtreecommitdiff
path: root/arch/x86/lib
diff options
context:
space:
mode:
authorPeter Zijlstra <peterz@infradead.org>2023-01-12 22:43:58 +0300
committerIngo Molnar <mingo@kernel.org>2023-01-13 13:48:17 +0300
commit69d4c0d3218692ffa56b0e1b9c76c50c699d7044 (patch)
tree632f322958ef60af5237ba029b2b82e5b4595c5d /arch/x86/lib
parent365bd03ff63fb7433a49c453472cf54830b677bf (diff)
downloadlinux-69d4c0d3218692ffa56b0e1b9c76c50c699d7044.tar.xz
entry, kasan, x86: Disallow overriding mem*() functions
KASAN cannot just hijack the mem*() functions, it needs to emit __asan_mem*() variants if it wants instrumentation (other sanitizers already do this). vmlinux.o: warning: objtool: sync_regs+0x24: call to memcpy() leaves .noinstr.text section vmlinux.o: warning: objtool: vc_switch_off_ist+0xbe: call to memcpy() leaves .noinstr.text section vmlinux.o: warning: objtool: fixup_bad_iret+0x36: call to memset() leaves .noinstr.text section vmlinux.o: warning: objtool: __sev_get_ghcb+0xa0: call to memcpy() leaves .noinstr.text section vmlinux.o: warning: objtool: __sev_put_ghcb+0x35: call to memcpy() leaves .noinstr.text section Remove the weak aliases to ensure nobody hijacks these functions and add them to the noinstr section. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195542.028523143@infradead.org
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/memcpy_64.S5
-rw-r--r--arch/x86/lib/memmove_64.S4
-rw-r--r--arch/x86/lib/memset_64.S4
3 files changed, 8 insertions, 5 deletions
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index dd8cd8831251..a64017602010 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -8,7 +8,7 @@
#include <asm/alternative.h>
#include <asm/export.h>
-.pushsection .noinstr.text, "ax"
+.section .noinstr.text, "ax"
/*
* We build a jump to memcpy_orig by default which gets NOPped out on
@@ -43,7 +43,7 @@ SYM_TYPED_FUNC_START(__memcpy)
SYM_FUNC_END(__memcpy)
EXPORT_SYMBOL(__memcpy)
-SYM_FUNC_ALIAS_WEAK(memcpy, __memcpy)
+SYM_FUNC_ALIAS(memcpy, __memcpy)
EXPORT_SYMBOL(memcpy)
/*
@@ -184,4 +184,3 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
RET
SYM_FUNC_END(memcpy_orig)
-.popsection
diff --git a/arch/x86/lib/memmove_64.S b/arch/x86/lib/memmove_64.S
index 724bbf83eb5b..02661861e5dd 100644
--- a/arch/x86/lib/memmove_64.S
+++ b/arch/x86/lib/memmove_64.S
@@ -13,6 +13,8 @@
#undef memmove
+.section .noinstr.text, "ax"
+
/*
* Implement memmove(). This can handle overlap between src and dst.
*
@@ -213,5 +215,5 @@ SYM_FUNC_START(__memmove)
SYM_FUNC_END(__memmove)
EXPORT_SYMBOL(__memmove)
-SYM_FUNC_ALIAS_WEAK(memmove, __memmove)
+SYM_FUNC_ALIAS(memmove, __memmove)
EXPORT_SYMBOL(memmove)
diff --git a/arch/x86/lib/memset_64.S b/arch/x86/lib/memset_64.S
index fc9ffd3ff3b2..6143b1a6fa2c 100644
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -6,6 +6,8 @@
#include <asm/alternative.h>
#include <asm/export.h>
+.section .noinstr.text, "ax"
+
/*
* ISO C memset - set a memory block to a byte value. This function uses fast
* string to get better performance than the original function. The code is
@@ -43,7 +45,7 @@ SYM_FUNC_START(__memset)
SYM_FUNC_END(__memset)
EXPORT_SYMBOL(__memset)
-SYM_FUNC_ALIAS_WEAK(memset, __memset)
+SYM_FUNC_ALIAS(memset, __memset)
EXPORT_SYMBOL(memset)
/*