From: Szabolcs Nagy <szabolcs.nagy@arm.com> To: libc-alpha@sourceware.org Cc: Jeremy Linton <jeremy.linton@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Mark Rutland <mark.rutland@arm.com>, Will Deacon <will.deacon@arm.com>, Mark Brown <broonie@kernel.org>, Florian Weimer <fweimer@redhat.com>, Kees Cook <keescook@chromium.org>, Salvatore Mesoraca <s.mesoraca16@gmail.com>, Lennart Poettering <mzxreary@0pointer.de>, Topi Miettinen <toiwoton@gmail.com>, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel-hardening@lists.openwall.com, linux-hardening@vger.kernel.org Subject: [PATCH 2/4] elf: Move note processing after l_phdr is updated [BZ #26831] Date: Tue, 3 Nov 2020 10:26:18 +0000 [thread overview] Message-ID: <7b008fd34f802456db3731a043ff56683b569ff7.1604393169.git.szabolcs.nagy@arm.com> (raw) In-Reply-To: <cover.1604393169.git.szabolcs.nagy@arm.com> Program headers are processed in two pass: after the first pass load segments are mmapped so in the second pass target specific note processing logic can access the notes. The second pass is moved later so various link_map fields are set up that may be useful for note processing such as l_phdr. --- elf/dl-load.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/elf/dl-load.c b/elf/dl-load.c index ceaab7f18e..673cf960a0 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1259,21 +1259,6 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, maplength, has_holes, loader); if (__glibc_unlikely (errstring != NULL)) goto call_lose; - - /* Process program headers again after load segments are mapped in - case processing requires accessing those segments. Scan program - headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY - exits. */ - for (ph = &phdr[l->l_phnum]; ph != phdr; --ph) - switch (ph[-1].p_type) - { - case PT_NOTE: - _dl_process_pt_note (l, fd, &ph[-1]); - break; - case PT_GNU_PROPERTY: - _dl_process_pt_gnu_property (l, fd, &ph[-1]); - break; - } } if (l->l_ld == 0) @@ -1481,6 +1466,21 @@ cannot enable executable stack as shared object requires"); /* Assign the next available module ID. */ l->l_tls_modid = _dl_next_tls_modid (); + /* Process program headers again after load segments are mapped in + case processing requires accessing those segments. Scan program + headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY + exits. */ + for (ph = &l->l_phdr[l->l_phnum]; ph != l->l_phdr; --ph) + switch (ph[-1].p_type) + { + case PT_NOTE: + _dl_process_pt_note (l, fd, &ph[-1]); + break; + case PT_GNU_PROPERTY: + _dl_process_pt_gnu_property (l, fd, &ph[-1]); + break; + } + #ifdef DL_AFTER_LOAD DL_AFTER_LOAD (l); #endif -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Szabolcs Nagy <szabolcs.nagy@arm.com> To: libc-alpha@sourceware.org Cc: Mark Rutland <mark.rutland@arm.com>, Florian Weimer <fweimer@redhat.com>, Kees Cook <keescook@chromium.org>, kernel-hardening@lists.openwall.com, Salvatore Mesoraca <s.mesoraca16@gmail.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will.deacon@arm.com>, linux-kernel@vger.kernel.org, Jeremy Linton <jeremy.linton@arm.com>, Mark Brown <broonie@kernel.org>, Lennart Poettering <mzxreary@0pointer.de>, linux-hardening@vger.kernel.org, Topi Miettinen <toiwoton@gmail.com>, linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/4] elf: Move note processing after l_phdr is updated [BZ #26831] Date: Tue, 3 Nov 2020 10:26:18 +0000 [thread overview] Message-ID: <7b008fd34f802456db3731a043ff56683b569ff7.1604393169.git.szabolcs.nagy@arm.com> (raw) In-Reply-To: <cover.1604393169.git.szabolcs.nagy@arm.com> Program headers are processed in two pass: after the first pass load segments are mmapped so in the second pass target specific note processing logic can access the notes. The second pass is moved later so various link_map fields are set up that may be useful for note processing such as l_phdr. --- elf/dl-load.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/elf/dl-load.c b/elf/dl-load.c index ceaab7f18e..673cf960a0 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1259,21 +1259,6 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, maplength, has_holes, loader); if (__glibc_unlikely (errstring != NULL)) goto call_lose; - - /* Process program headers again after load segments are mapped in - case processing requires accessing those segments. Scan program - headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY - exits. */ - for (ph = &phdr[l->l_phnum]; ph != phdr; --ph) - switch (ph[-1].p_type) - { - case PT_NOTE: - _dl_process_pt_note (l, fd, &ph[-1]); - break; - case PT_GNU_PROPERTY: - _dl_process_pt_gnu_property (l, fd, &ph[-1]); - break; - } } if (l->l_ld == 0) @@ -1481,6 +1466,21 @@ cannot enable executable stack as shared object requires"); /* Assign the next available module ID. */ l->l_tls_modid = _dl_next_tls_modid (); + /* Process program headers again after load segments are mapped in + case processing requires accessing those segments. Scan program + headers backward so that PT_NOTE can be skipped if PT_GNU_PROPERTY + exits. */ + for (ph = &l->l_phdr[l->l_phnum]; ph != l->l_phdr; --ph) + switch (ph[-1].p_type) + { + case PT_NOTE: + _dl_process_pt_note (l, fd, &ph[-1]); + break; + case PT_GNU_PROPERTY: + _dl_process_pt_gnu_property (l, fd, &ph[-1]); + break; + } + #ifdef DL_AFTER_LOAD DL_AFTER_LOAD (l); #endif -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-11-03 10:27 UTC|newest] Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-11-03 10:25 [PATCH 0/4] aarch64: avoid mprotect(PROT_BTI|PROT_EXEC) [BZ #26831] Szabolcs Nagy 2020-11-03 10:25 ` Szabolcs Nagy 2020-11-03 10:25 ` [PATCH 1/4] elf: Pass the fd to note processing " Szabolcs Nagy 2020-11-03 10:25 ` Szabolcs Nagy 2020-11-03 10:26 ` Szabolcs Nagy [this message] 2020-11-03 10:26 ` [PATCH 2/4] elf: Move note processing after l_phdr is updated " Szabolcs Nagy 2020-11-03 10:38 ` Florian Weimer 2020-11-03 10:38 ` Florian Weimer 2020-11-03 10:38 ` Florian Weimer 2020-11-03 12:36 ` H.J. Lu 2020-11-03 12:36 ` H.J. Lu 2020-11-03 12:36 ` H.J. Lu 2020-11-03 15:04 ` Szabolcs Nagy 2020-11-03 15:04 ` Szabolcs Nagy 2020-11-03 15:27 ` H.J. Lu 2020-11-03 15:27 ` H.J. Lu 2020-11-03 15:27 ` H.J. Lu 2020-11-03 10:26 ` [PATCH 3/4] aarch64: Use mmap to add PROT_BTI instead of mprotect " Szabolcs Nagy 2020-11-03 10:26 ` Szabolcs Nagy 2020-11-03 10:34 ` Florian Weimer 2020-11-03 10:34 ` Florian Weimer 2020-11-03 10:34 ` Florian Weimer 2020-11-03 10:26 ` [PATCH 4/4] aarch64: Remove the bti link_map field " Szabolcs Nagy 2020-11-03 10:26 ` Szabolcs Nagy 2020-11-03 17:34 ` [PATCH 0/4] aarch64: avoid mprotect(PROT_BTI|PROT_EXEC) " Mark Brown 2020-11-03 17:34 ` Mark Brown 2020-11-04 5:41 ` Jeremy Linton 2020-11-04 5:41 ` Jeremy Linton 2020-11-04 8:57 ` Szabolcs Nagy 2020-11-04 8:57 ` Szabolcs Nagy 2020-11-04 14:41 ` Catalin Marinas 2020-11-04 14:41 ` Catalin Marinas 2020-11-04 14:45 ` Florian Weimer 2020-11-04 14:45 ` Florian Weimer 2020-11-04 14:45 ` Florian Weimer 2020-11-04 10:50 ` Mark Brown 2020-11-04 10:50 ` Mark Brown 2020-11-04 18:47 ` Jeremy Linton 2020-11-04 18:47 ` Jeremy Linton 2020-11-04 18:53 ` Mark Brown 2020-11-04 18:53 ` Mark Brown 2020-11-04 9:02 ` Topi Miettinen 2020-11-04 9:02 ` Topi Miettinen 2020-11-04 9:20 ` Will Deacon 2020-11-04 9:20 ` Will Deacon 2020-11-04 9:29 ` Florian Weimer 2020-11-04 9:29 ` Florian Weimer 2020-11-04 9:29 ` Florian Weimer 2020-11-04 9:55 ` Topi Miettinen 2020-11-04 9:55 ` Topi Miettinen 2020-11-04 14:35 ` Catalin Marinas 2020-11-04 14:35 ` Catalin Marinas 2020-11-04 15:19 ` Topi Miettinen 2020-11-04 15:19 ` Topi Miettinen 2020-11-04 16:08 ` Szabolcs Nagy 2020-11-04 16:08 ` Szabolcs Nagy 2020-11-04 15:20 ` Mark Rutland 2020-11-04 15:20 ` Mark Rutland 2020-11-04 18:59 ` Jeremy Linton 2020-11-04 18:59 ` Jeremy Linton 2020-11-05 11:31 ` Szabolcs Nagy 2020-11-05 11:31 ` Szabolcs Nagy
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