Re: [PATCH] perf tools: Fix debuginfo search for Ubuntu

[Adrian Hunter]

On 26/05/20 6:29 pm, Adrian Hunter wrote:
> Reportedly, from 19.10 Ubuntu has begun mixing up the location of some
> debug symbol files, putting files expected to be in
> /usr/lib/debug/usr/lib into /usr/lib/debug/lib instead. Fix by adding
> another dso_binary_type.
> 
> Example on Ubuntu 20.04
> 
>   Before:
> 
>     $ perf record -e intel_pt//u uname
>     Linux
>     [ perf record: Woken up 1 times to write data ]
>     [ perf record: Captured and wrote 0.030 MB perf.data ]
>     $ perf script --call-trace | head -5
>            uname 14003 [005] 15321.764958566:  cbr: 42 freq: 4219 MHz (156%)
>            uname 14003 [005] 15321.764958566: (/usr/lib/x86_64-linux-gnu/ld-2.31.so              )          7f1e71cc4100
>            uname 14003 [005] 15321.764961566: (/usr/lib/x86_64-linux-gnu/ld-2.31.so              )              7f1e71cc4df0
>            uname 14003 [005] 15321.764961900: (/usr/lib/x86_64-linux-gnu/ld-2.31.so              )              7f1e71cc4e18
>            uname 14003 [005] 15321.764963233: (/usr/lib/x86_64-linux-gnu/ld-2.31.so              )              7f1e71cc5128
> 
>   After:
> 
>     $ perf script --call-trace | head -5
>            uname 14003 [005] 15321.764958566:  cbr: 42 freq: 4219 MHz (156%)
>            uname 14003 [005] 15321.764958566: (/usr/lib/x86_64-linux-gnu/ld-2.31.so              )      _start
>            uname 14003 [005] 15321.764961566: (/usr/lib/x86_64-linux-gnu/ld-2.31.so              )          _dl_start
>            uname 14003 [005] 15321.764961900: (/usr/lib/x86_64-linux-gnu/ld-2.31.so              )          _dl_start
>            uname 14003 [005] 15321.764963233: (/usr/lib/x86_64-linux-gnu/ld-2.31.so              )          _dl_start
> 
> Reported-by: Travis Downs <travis.downs@xxxxxxxxx>
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
>  tools/perf/util/dso.c          | 14 ++++++++++++++
>  tools/perf/util/dso.h          |  1 +
>  tools/perf/util/probe-finder.c |  1 +
>  tools/perf/util/symbol.c       |  2 ++
>  4 files changed, 18 insertions(+)
> 
> diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
> index e68e1375e3c0..15b635d6c83c 100644
> --- a/tools/perf/util/dso.c
> +++ b/tools/perf/util/dso.c
> @@ -47,6 +47,7 @@ char dso__symtab_origin(const struct dso *dso)
>  		[DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO]	= 'D',
>  		[DSO_BINARY_TYPE__FEDORA_DEBUGINFO]		= 'f',
>  		[DSO_BINARY_TYPE__UBUNTU_DEBUGINFO]		= 'u',
> +		[DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO]	= 'x',
>  		[DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO]	= 'o',
>  		[DSO_BINARY_TYPE__BUILDID_DEBUGINFO]		= 'b',
>  		[DSO_BINARY_TYPE__SYSTEM_PATH_DSO]		= 'd',
> @@ -129,6 +130,19 @@ int dso__read_binary_type_filename(const struct dso *dso,
>  		snprintf(filename + len, size - len, "%s", dso->long_name);
>  		break;
>  
> +	case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
> +		/*
> +		 * Ubuntu can mixup /usr/lib with /lib, putting debuginfo in
> +		 * /usr/lib/debug/lib when it is expected to be in
> +		 * /usr/lib/debug/usr/lib
> +		 */
> +		if (strlen(dso->long_name) < 9 ||
> +		    strncmp(dso->long_name, "/usr/lib/", 9))
> +			ret = -1;

Oops, pushed send too soon.  That should be:

		if (strlen(dso->long_name) < 9 ||
		    strncmp(dso->long_name, "/usr/lib/", 9)) {
			ret = -1;
			break;
		}

> +		len = __symbol__join_symfs(filename, size, "/usr/lib/debug");
> +		snprintf(filename + len, size - len, "%s", dso->long_name + 4);
> +		break;
> +
>  	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
>  	{
>  		const char *last_slash;
> diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
> index 42b3a278ac59..8b7958f02609 100644
> --- a/tools/perf/util/dso.h
> +++ b/tools/perf/util/dso.h
> @@ -30,6 +30,7 @@ enum dso_binary_type {
>  	DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO,
>  	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
>  	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
> +	DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
>  	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
>  	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
>  	DSO_BINARY_TYPE__GUEST_KMODULE,
> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> index e4cff49384f4..55924255c535 100644
> --- a/tools/perf/util/probe-finder.c
> +++ b/tools/perf/util/probe-finder.c
> @@ -101,6 +101,7 @@ enum dso_binary_type distro_dwarf_types[] = {
>  	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
>  	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
>  	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
> +	DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
>  	DSO_BINARY_TYPE__NOT_FOUND,
>  };
>  
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index 7725c83996f4..44d81f90b604 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -79,6 +79,7 @@ static enum dso_binary_type binary_type_symtab[] = {
>  	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
>  	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
>  	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
> +	DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
>  	DSO_BINARY_TYPE__NOT_FOUND,
>  };
>  
> @@ -1529,6 +1530,7 @@ static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
>  	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
>  	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
>  	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
> +	case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
>  	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
>  	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
>  		return !kmod && dso->kernel == DSO_TYPE_USER;
>