Date: Mon, 16 Oct 2023 16:59:18 GMT From: Brooks Davis <brooks@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 9735cc0e4182 - main - libprocstat: simplify auxv value conversion Message-ID: <202310161659.39GGxIc6028816@gitrepo.freebsd.org>
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The branch main has been updated by brooks: URL: https://cgit.FreeBSD.org/src/commit/?id=9735cc0e41825bb9e95d16433d381ffe4c190f38 commit 9735cc0e41825bb9e95d16433d381ffe4c190f38 Author: Brooks Davis <brooks@FreeBSD.org> AuthorDate: 2023-10-16 16:52:57 +0000 Commit: Brooks Davis <brooks@FreeBSD.org> CommitDate: 2023-10-16 16:58:27 +0000 libprocstat: simplify auxv value conversion Avoid a weird dance through the union and treat all 32-bit values as unsigned integers. This avoids sign extension of flags and userspace pointers. Reviewed by: markj Sponsored by: DARPA Differential Revision: https://reviews.freebsd.org/D42198 --- lib/libprocstat/libprocstat.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/lib/libprocstat/libprocstat.c b/lib/libprocstat/libprocstat.c index a302310dfb9a..e5481c53eea1 100644 --- a/lib/libprocstat/libprocstat.c +++ b/lib/libprocstat/libprocstat.c @@ -2414,7 +2414,6 @@ procstat_getauxv32_sysctl(pid_t pid, unsigned int *cntp) { Elf_Auxinfo *auxv; Elf32_Auxinfo *auxv32; - void *ptr; size_t len; unsigned int i, count; int name[4]; @@ -2448,8 +2447,17 @@ procstat_getauxv32_sysctl(pid_t pid, unsigned int *cntp) * necessarily true. */ auxv[i].a_type = auxv32[i].a_type; - ptr = &auxv32[i].a_un; - auxv[i].a_un.a_val = *((uint32_t *)ptr); + /* + * Don't sign extend values. Existing entries are positive + * integers or pointers. Under freebsd32, programs typically + * have a full [0, 2^32) address space (perhaps minus the last + * page) and treating this as a signed integer would be + * confusing since these are not kernel pointers. + * + * XXX: A more complete translation would be ABI and + * type-aware. + */ + auxv[i].a_un.a_val = (uint32_t)auxv32[i].a_un.a_val; } *cntp = count; out:
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