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authorJosh Poimboeuf <jpoimboe@redhat.com>2018-05-18 08:47:12 +0200
committerIngo Molnar <mingo@kernel.org>2018-06-21 16:34:56 +0200
commitd31a580266eeb1f355df90fde8a71f480e30ad70 (patch)
treecd4bbc37279a4f72257c8338c4051a441239d570 /tools/objtool
parent0c414367c04eeb00c3ebfee0b74c9e7f3b95fd62 (diff)
downloadlinux-d31a580266eeb1f355df90fde8a71f480e30ad70.tar.bz2
x86/unwind/orc: Detect the end of the stack
The existing UNWIND_HINT_EMPTY annotations happen to be good indicators of where entry code calls into C code for the first time. So also use them to mark the end of the stack for the ORC unwinder. Use that information to set unwind->error if the ORC unwinder doesn't unwind all the way to the end. This will be needed for enabling HAVE_RELIABLE_STACKTRACE for the ORC unwinder so we can use it with the livepatch consistency model. Thanks to Jiri Slaby for teaching the ORCs about the unwind hints. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/lkml/20180518064713.26440-5-jslaby@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/objtool')
-rw-r--r--tools/objtool/arch/x86/include/asm/orc_types.h2
-rw-r--r--tools/objtool/check.c1
-rw-r--r--tools/objtool/check.h2
-rw-r--r--tools/objtool/orc_dump.c3
-rw-r--r--tools/objtool/orc_gen.c2
5 files changed, 8 insertions, 2 deletions
diff --git a/tools/objtool/arch/x86/include/asm/orc_types.h b/tools/objtool/arch/x86/include/asm/orc_types.h
index 9c9dc579bd7d..46f516dd80ce 100644
--- a/tools/objtool/arch/x86/include/asm/orc_types.h
+++ b/tools/objtool/arch/x86/include/asm/orc_types.h
@@ -88,6 +88,7 @@ struct orc_entry {
unsigned sp_reg:4;
unsigned bp_reg:4;
unsigned type:2;
+ unsigned end:1;
} __packed;
/*
@@ -101,6 +102,7 @@ struct unwind_hint {
s16 sp_offset;
u8 sp_reg;
u8 type;
+ u8 end;
};
#endif /* __ASSEMBLY__ */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 38047c6aa575..8491beb1a636 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1156,6 +1156,7 @@ static int read_unwind_hints(struct objtool_file *file)
cfa->offset = hint->sp_offset;
insn->state.type = hint->type;
+ insn->state.end = hint->end;
}
return 0;
diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index c6b68fcb926f..95700a2bcb7c 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -31,7 +31,7 @@ struct insn_state {
int stack_size;
unsigned char type;
bool bp_scratch;
- bool drap;
+ bool drap, end;
int drap_reg, drap_offset;
struct cfi_reg vals[CFI_NUM_REGS];
};
diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c
index c3343820916a..faa444270ee3 100644
--- a/tools/objtool/orc_dump.c
+++ b/tools/objtool/orc_dump.c
@@ -203,7 +203,8 @@ int orc_dump(const char *_objname)
print_reg(orc[i].bp_reg, orc[i].bp_offset);
- printf(" type:%s\n", orc_type_name(orc[i].type));
+ printf(" type:%s end:%d\n",
+ orc_type_name(orc[i].type), orc[i].end);
}
elf_end(elf);
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index 18384d9be4e1..3f98dcfbc177 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -31,6 +31,8 @@ int create_orc(struct objtool_file *file)
struct cfi_reg *cfa = &insn->state.cfa;
struct cfi_reg *bp = &insn->state.regs[CFI_BP];
+ orc->end = insn->state.end;
+
if (cfa->base == CFI_UNDEFINED) {
orc->sp_reg = ORC_REG_UNDEFINED;
continue;