Date: Thu, 5 Nov 2020 16:47:24 +0000 (UTC) From: Leandro Lupori <luporl@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r367392 - head/lib/libpmcstat Message-ID: <202011051647.0A5GlOrA097877@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: luporl Date: Thu Nov 5 16:47:23 2020 New Revision: 367392 URL: https://svnweb.freebsd.org/changeset/base/367392 Log: pmcstat: fix PPC kernel symbol resolution PowerPC kernel is of DYN type and it has a base address where it is initially loaded, before being relocated. As the start address passed to pmcstat_image_link() is where the kernel was relocated to, but the symbols always use the original base address, we need to subtract it to get the correct offset. Reviewed by: jhibbits Sponsored by: Eldorado Research Institute (eldorado.org.br) Differential Revision: https://reviews.freebsd.org/D26114 Modified: head/lib/libpmcstat/libpmcstat_image.c Modified: head/lib/libpmcstat/libpmcstat_image.c ============================================================================== --- head/lib/libpmcstat/libpmcstat_image.c Thu Nov 5 16:41:28 2020 (r367391) +++ head/lib/libpmcstat/libpmcstat_image.c Thu Nov 5 16:47:23 2020 (r367392) @@ -32,6 +32,7 @@ __FBSDID("$FreeBSD$"); #include <sys/param.h> #include <sys/endian.h> #include <sys/pmc.h> +#include <sys/sysctl.h> #include <sys/imgact_aout.h> #include <sys/imgact_elf.h> @@ -176,12 +177,36 @@ pmcstat_image_link(struct pmcstat_process *pp, struct { struct pmcstat_pcmap *pcm, *pcmnew; uintfptr_t offset; +#ifdef __powerpc__ + unsigned long kernbase; + size_t kernbase_len; +#endif assert(image->pi_type != PMCSTAT_IMAGE_UNKNOWN && image->pi_type != PMCSTAT_IMAGE_INDETERMINABLE); if ((pcmnew = malloc(sizeof(*pcmnew))) == NULL) err(EX_OSERR, "ERROR: Cannot create a map entry"); + + /* + * PowerPC kernel is of DYN type and it has a base address + * where it is initially loaded, before being relocated. + * As the address in 'start' is where the kernel was relocated to, + * but the symbols always use the original base address, we need to + * subtract it to get the correct offset. + */ +#ifdef __powerpc__ + if (pp->pp_pid == -1) { + kernbase = 0; + kernbase_len = sizeof(kernbase); + if (sysctlbyname("kern.base_address", &kernbase, &kernbase_len, + NULL, 0) == -1) + warnx( + "WARNING: Could not retrieve kernel base address"); + else + start -= kernbase; + } +#endif /* * Adjust the map entry to only cover the text portion
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202011051647.0A5GlOrA097877>