From: Arvind Sankar <nivedita@alum.mit.edu> To: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org, linux-kernel@vger.kernel.org, Michael Matz <matz@suse.de> Subject: [PATCH v2] x86/boot: Use 32-bit (zero-extended) move for z_output_len Date: Tue, 11 Feb 2020 12:33:33 -0500 [thread overview] Message-ID: <20200211173333.1722739-1-nivedita@alum.mit.edu> (raw) In-Reply-To: <20200211161739.GE32279@zn.tnic> z_output_len is the size of the decompressed payload (i.e. vmlinux + vmlinux.relocs) and is generated as an unsigned 32-bit quantity by mkpiggy.c. The current movq $z_output_len, %r9 instruction generates a sign-extended move to %r9. Using movl $z_output_len, %r9d will instead zero-extend into %r9, which is appropriate for an unsigned 32-bit quantity. This is also what we already do for z_input_len, the size of the compressed payload. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> --- v2: Improve commit message arch/x86/boot/compressed/head_64.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 1f1f6c8139b3..03369246a4ff 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -484,7 +484,7 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) leaq input_data(%rip), %rdx /* input_data */ movl $z_input_len, %ecx /* input_len */ movq %rbp, %r8 /* output target address */ - movq $z_output_len, %r9 /* decompressed length, end of relocs */ + movl $z_output_len, %r9d /* decompressed length, end of relocs */ call extract_kernel /* returns kernel location in %rax */ popq %rsi -- 2.24.1
next prev parent reply other threads:[~2020-02-11 17:33 UTC|newest] Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-07 19:44 [PATCH 1/3] x86/boot/compressed/32: Simplify calculation of output address Arvind Sankar 2020-01-07 19:44 ` [PATCH 2/3] x86/boot/compressed/64: Use leal to initialize boot stack pointer Arvind Sankar 2020-02-12 12:04 ` [tip: x86/boot] x86/boot/compressed/64: Use LEA " tip-bot2 for Arvind Sankar 2020-01-07 19:44 ` [PATCH 3/3] x86/boot/compressed/64: Use 32-bit move for z_output_len Arvind Sankar 2020-02-11 16:17 ` Borislav Petkov 2020-02-11 17:33 ` Arvind Sankar [this message] 2020-02-11 18:15 ` [PATCH v2] x86/boot: Use 32-bit (zero-extended) " Borislav Petkov 2020-02-11 19:27 ` Arvind Sankar 2020-02-12 9:47 ` Borislav Petkov 2020-02-12 12:04 ` [tip: x86/boot] x86/boot/compressed/64: Use 32-bit (zero-extended) MOV " tip-bot2 for Arvind Sankar 2020-01-23 11:04 ` [tip: x86/asm] x86/boot: Simplify calculation of output address tip-bot2 for Arvind Sankar
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200211173333.1722739-1-nivedita@alum.mit.edu \ --to=nivedita@alum.mit.edu \ --cc=bp@alien8.de \ --cc=hpa@zytor.com \ --cc=linux-kernel@vger.kernel.org \ --cc=matz@suse.de \ --cc=mingo@redhat.com \ --cc=tglx@linutronix.de \ --cc=x86@kernel.org \ --subject='Re: [PATCH v2] x86/boot: Use 32-bit (zero-extended) move for z_output_len' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).