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authorUlises Mendez Martinez <umendez@google.com>2026-09-04 15:07:09 +0000
committerJosh Poimboeuf <jpoimboe@kernel.org>2026-09-13 18:15:43 -0700
commit7e61560628d17ea6b1d8ee370f6d42694cff8758 (patch)
treee6080164b2f4c4c419894bdb3ce4d956ca9a98c5 /arch/powerpc/sysdev/dcr-low.S
downloadlinux-stable-7e61560628d17ea6b1d8ee370f6d42694cff8758.tar.gz
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objtool: Validate disassembler headers in libopcodes probegrafted
commit 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") tested for libopcodes availability by linking a test snippet with a forward declaration of disassemble_init_for_target(). However, testing symbol linkage with an extern declaration only verifies the presence of the library (.so/.a) and bypasses checking for development headers (binutils-dev). On systems where libopcodes is present without development headers installed, the probe succeeds, enabling BUILD_DISAS. Subsequent compilation of objtool then fails: fatal error: 'bfd.h' file not found 113 | #include <bfd.h> Additionally, the probe invokes $(HOSTCC) without $(HOSTCFLAGS), ignoring any sysroot or include flags specified for the host compiler. Fix this by including <bfd.h> and <dis-asm.h> directly in the test snippet, passing $(HOSTCFLAGS) so host compiler options are respected, and defining PACKAGE="objtool" to satisfy the configuration check in <bfd.h>. Fixes: 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") Fixes: 436326bc525d ("objtool: fix build failure due to missing libopcodes check") Reported-by: Alice Ryhl <aliceryhl@google.com> Assisted-by: Antigravity:Gemini-Next Signed-off-by: Ulises Mendez Martinez <umendez@google.com> Link: https://patch.msgid.link/20260904150710.2997558-1-umendez@google.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Diffstat (limited to 'arch/powerpc/sysdev/dcr-low.S')
-rw-r--r--arch/powerpc/sysdev/dcr-low.S44
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/dcr-low.S b/arch/powerpc/sysdev/dcr-low.S
new file mode 100644
index 000000000..e8401b205
--- /dev/null
+++ b/arch/powerpc/sysdev/dcr-low.S
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * "Indirect" DCR access
+ *
+ * Copyright (c) 2004 Eugene Surovegin <ebs@ebshome.net>
+ */
+
+#include <linux/export.h>
+#include <asm/ppc_asm.h>
+#include <asm/processor.h>
+#include <asm/bug.h>
+
+#define DCR_ACCESS_PROLOG(table) \
+ cmplwi cr0,r3,1024; \
+ rlwinm r3,r3,4,18,27; \
+ lis r5,table@h; \
+ ori r5,r5,table@l; \
+ add r3,r3,r5; \
+ bge- 1f; \
+ mtctr r3; \
+ bctr; \
+1: trap; \
+ EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0; \
+ blr
+
+_GLOBAL(__mfdcr)
+ DCR_ACCESS_PROLOG(__mfdcr_table)
+EXPORT_SYMBOL(__mfdcr)
+
+_GLOBAL(__mtdcr)
+ DCR_ACCESS_PROLOG(__mtdcr_table)
+EXPORT_SYMBOL(__mtdcr)
+
+__mfdcr_table:
+ mfdcr r3,0; blr
+__mtdcr_table:
+ mtdcr 0,r4; blr
+
+dcr = 1
+ .rept 1023
+ mfdcr r3,dcr; blr
+ mtdcr dcr,r4; blr
+ dcr = dcr + 1
+ .endr