From: Christoph Hellwig <hch@lst.de> To: Andrew Morton <akpm@linux-foundation.org>, Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jeremy Kerr <jk@ozlabs.org>, Arnd Bergmann <arnd@arndb.de>, "Eric W . Biederman" <ebiederm@xmission.com>, linuxppc-dev@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 5/7] binfmt_elf_fdpic: remove the set_fs(KERNEL_DS) in elf_fdpic_core_dump Date: Tue, 21 Apr 2020 17:42:02 +0200 Message-ID: <20200421154204.252921-6-hch@lst.de> (raw) In-Reply-To: <20200421154204.252921-1-hch@lst.de> There is no logic in elf_fdpic_core_dump itself, or in the various arch helpers called from it which use uaccess routines on kernel pointers except for the file writes thate are nicely encapsulated by using __kernel_write in dump_emit. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/binfmt_elf_fdpic.c | 31 ++++++++++++------------------- 1 file changed, 12 insertions(+), 19 deletions(-) diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 240f66663543..c62c17a5c34a 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -1549,7 +1549,6 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) { #define NUM_NOTES 6 int has_dumped = 0; - mm_segment_t fs; int segs; int i; struct vm_area_struct *vma; @@ -1678,9 +1677,6 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); #endif - fs = get_fs(); - set_fs(KERNEL_DS); - offset += sizeof(*elf); /* Elf header */ offset += segs * sizeof(struct elf_phdr); /* Program headers */ @@ -1695,7 +1691,7 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); if (!phdr4note) - goto end_coredump; + goto cleanup; fill_elf_note_phdr(phdr4note, sz, offset); offset += sz; @@ -1711,17 +1707,17 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) if (e_phnum == PN_XNUM) { shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); if (!shdr4extnum) - goto end_coredump; + goto cleanup; fill_extnum_info(elf, shdr4extnum, e_shoff, segs); } offset = dataoff; if (!dump_emit(cprm, elf, sizeof(*elf))) - goto end_coredump; + goto cleanup; if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) - goto end_coredump; + goto cleanup; /* write program headers for segments dump */ for (vma = current->mm->mmap; vma; vma = vma->vm_next) { @@ -1745,16 +1741,16 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) phdr.p_align = ELF_EXEC_PAGESIZE; if (!dump_emit(cprm, &phdr, sizeof(phdr))) - goto end_coredump; + goto cleanup; } if (!elf_core_write_extra_phdrs(cprm, offset)) - goto end_coredump; + goto cleanup; /* write out the notes section */ for (i = 0; i < numnote; i++) if (!writenote(notes + i, cprm)) - goto end_coredump; + goto cleanup; /* write out the thread status notes section */ list_for_each(t, &thread_list) { @@ -1763,21 +1759,21 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) for (i = 0; i < tmp->num_notes; i++) if (!writenote(&tmp->notes[i], cprm)) - goto end_coredump; + goto cleanup; } if (!dump_skip(cprm, dataoff - cprm->pos)) - goto end_coredump; + goto cleanup; if (!elf_fdpic_dump_segments(cprm)) - goto end_coredump; + goto cleanup; if (!elf_core_write_extra_data(cprm)) - goto end_coredump; + goto cleanup; if (e_phnum == PN_XNUM) { if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) - goto end_coredump; + goto cleanup; } if (cprm->file->f_pos != offset) { @@ -1787,9 +1783,6 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) cprm->file->f_pos, offset); } -end_coredump: - set_fs(fs); - cleanup: while (!list_empty(&thread_list)) { struct list_head *tmp = thread_list.next; -- 2.26.1
next prev parent reply index Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-04-21 15:41 remove set_fs calls from the exec and coredump code v3 Christoph Hellwig 2020-04-21 15:41 ` [PATCH 1/7] powerpc/spufs: simplify spufs core dumping Christoph Hellwig 2020-04-21 18:49 ` Al Viro 2020-04-21 19:01 ` Christoph Hellwig 2020-04-21 19:19 ` Al Viro 2020-04-21 19:25 ` Al Viro 2020-04-21 15:41 ` [PATCH 2/7] signal: factor copy_siginfo_to_external32 from copy_siginfo_to_user32 Christoph Hellwig 2020-04-26 4:47 ` Andrew Morton 2020-04-26 7:40 ` Christoph Hellwig 2020-04-27 22:40 ` Andrew Morton 2020-04-28 7:09 ` Christoph Hellwig 2020-04-28 7:45 ` Christophe Leroy 2020-04-28 7:48 ` Christoph Hellwig 2020-04-28 19:56 ` [PATCH] fixup! " Arnd Bergmann 2020-04-29 6:17 ` Christophe Leroy 2020-04-29 6:29 ` Christoph Hellwig 2020-04-29 6:44 ` Christoph Hellwig 2020-04-29 8:07 ` Arnd Bergmann 2020-04-29 9:42 ` Christoph Hellwig 2020-04-29 11:28 ` Arnd Bergmann 2020-04-29 11:53 ` Christoph Hellwig 2020-04-29 12:34 ` Arnd Bergmann 2020-04-21 15:42 ` [PATCH 3/7] binfmt_elf: femove the set_fs in fill_siginfo_note Christoph Hellwig 2020-04-21 15:42 ` [PATCH 4/7] binfmt_elf: remove the set_fs(KERNEL_DS) in elf_core_dump Christoph Hellwig 2020-04-21 15:42 ` Christoph Hellwig [this message] 2020-04-21 15:42 ` [PATCH 6/7] exec: simplify the copy_strings_kernel calling convention Christoph Hellwig 2020-04-21 15:42 ` [PATCH 7/7] exec: open code copy_string_kernel Christoph Hellwig
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