The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is
similar in concept to a DWARF unwinder. The difference is that the format
of the ORC data is much simpler than DWARF, which in turn allows the ORC
unwinder to be much simpler and faster.
The ORC data consists of unwind tables which are generated by objtool.
After analyzing all the code paths of a .o file, it determines information
about the stack state at each instruction address in the file and outputs
that information to the .orc_unwind and .orc_unwind_ip sections.
The per-object ORC sections are combined at link time and are sorted and
post-processed at boot time. The unwinder uses the resulting data to
correlate instruction addresses with their stack states at run time.
Most of the logic are similar with x86, in order to get ra info before ra
is saved into stack, add ra_reg and ra_offset into orc_entry. At the same
time, modify some arch-specific code to silence the objtool warnings.
Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
The {copy, clear}_user function should returns number of bytes that
could not be {copied, cleared}. So, try to {copy, clear} byte by byte
when ld.{d,w,h} and st.{d,w,h} trapped into an exception.
Reviewed-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Weihao Li <liweihao@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Commit ddb5cdbafa ("kbuild: generate KSYMTAB entries by modpost")
deprecated <asm/export.h>, which is now a wrapper of <linux/export.h>.
Replace #include <asm/export.h> with #include <linux/export.h>.
After all the <asm/export.h> lines are converted, <asm/export.h> and
<asm-generic/export.h> will be removed.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This patch fixes an underflow issue in the return value within the
exception path, specifically at .Llt8 when the remaining length is less
than 8 bytes.
Cc: stable@vger.kernel.org
Fixes: 8941e93ca5 ("LoongArch: Optimize memory ops (memset/memcpy/memmove)")
Reported-by: Weihao Li <liweihao@loongson.cn>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Use the `.L_xxx` label to improve fixup code and then remove the .fixup
section usage.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Consolidate all the __ex_table constuction code with a _ASM_EXTABLE or
_asm_extable helper.
There should be no functional change as a result of this patch.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Support for the syntactic sugar is present in upstream binutils port
from the beginning. Use it for shorter lines and better consistency.
Generated code should be identical.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
