Re: [PATCH 2/2] perf tools: add automatic remapping of Android libraries

From: Jiri Olsa
Date: Mon May 19 2014 - 05:59:33 EST


On Sat, May 17, 2014 at 01:14:47AM +0200, Stephane Eranian wrote:
> From: Michael Lentine <mlentine@xxxxxxxxxx>
>
> This patch automtically adjusts the path of MMAP records
> associated with Android system libraries. It enables running
> perf reporting tools directly on the Android system natively.

could the changelog have more info about the lib name changes?

SNIP

> +
> + if (!strncmp(filename, "/data/app-lib", 13)) {
> + char *apk_path;
> +
> + if (!app_abi_length)
> + return false;
> +
> + new_length = 7 + app_abi_length + lib_length;
> +
> + apk_path = getenv("APK_PATH");
> + if(apk_path) {
> + snprintf(*newfilename, new_length + strlen(apk_path) + 1,
> + "%s/libs/%s/%s", apk_path, app_abi, libname);
> + } else {
> + snprintf(*newfilename, new_length,
> + "libs/%s/%s", app_abi, libname);
> + }

missing check for overflowing PATH_MAX for 'new_length' and 'new_length + strlen(apk_path) + 1'

> + return true;
> + }
> +
> + if (!strncmp(filename, "/system/lib/", 11)) {
> + char *ndk, *app;
> + const char *arch;
> + size_t ndk_length;
> + size_t app_length;
> +
> + ndk = getenv("NDK_ROOT");
> + app = getenv("APP_PLATFORM");
> +
> + if (!(ndk && app))
> + return false;
> +
> + ndk_length = strlen(ndk);
> + app_length = strlen(app);
> +
> + if (!(ndk_length && app_length && app_abi_length))
> + return false;
> +
> + arch = !strncmp(app_abi, "arm", 3) ? "arm" :
> + !strncmp(app_abi, "mips", 4) ? "mips" :
> + !strncmp(app_abi, "x86", 3) ? "x86" : NULL;
> +
> + if (!arch)
> + return false;
> +
> + new_length = 27 + ndk_length +
> + app_length + lib_length
> + + strlen(arch);

missing check for overflowing PATH_MAX for 'new_length'

> +
> + snprintf(*newfilename, new_length,
> + "%s/platforms/%s/arch-%s/usr/lib/%s",
> + ndk, app, arch, libname);
> +
> + return true;
> + }
> + return false;
> +}
> +

SNIP

> + if (android) {
> + char *newfilename_ptr = newfilename;
> + if (replace_android_lib(filename, &newfilename_ptr))
> + filename = newfilename;

Why is the newfilename_ptr needed? We could pass newfilename directly
to replace_android_lib function

if (replace_android_lib(filename, newfilename))
filename = newfilename;

thanks,
jirka
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