diff mbox

[4/7] x86: kexec_file: remove X86_64 dependency from prepare_elf64_headers()

Message ID 20180227044814.24808-5-takahiro.akashi@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

AKASHI Takahiro Feb. 27, 2018, 4:48 a.m. UTC 
The code guarded by CONFIG_X86_64 is necessary on some architectures
which have a dedicated kernel mapping outside of linear memory mapping.
(arm64 is among those.)

In this patch, an additional argument, kernel_map, is added to enable/
disable the code removing #ifdef.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
---
 arch/x86/kernel/crash.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

Comments

Dave Young March 2, 2018, 5:19 a.m. UTC | #1 
On 02/27/18 at 01:48pm, AKASHI Takahiro wrote:
> The code guarded by CONFIG_X86_64 is necessary on some architectures
> which have a dedicated kernel mapping outside of linear memory mapping.
> (arm64 is among those.)
> 
> In this patch, an additional argument, kernel_map, is added to enable/
> disable the code removing #ifdef.
> 
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Cc: Dave Young <dyoung@redhat.com>
> Cc: Vivek Goyal <vgoyal@redhat.com>
> Cc: Baoquan He <bhe@redhat.com>
> ---
>  arch/x86/kernel/crash.c | 25 +++++++++++++------------
>  1 file changed, 13 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index 2123fa0efc17..913fd8021f8a 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -347,7 +347,7 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
>  	return 0;
>  }
>  
> -static int prepare_elf64_headers(struct crash_elf_data *ced,
> +static int prepare_elf64_headers(struct crash_elf_data *ced, int kernel_map,
>  		void **addr, unsigned long *sz)
>  {
>  	Elf64_Ehdr *ehdr;
> @@ -414,17 +414,17 @@ static int prepare_elf64_headers(struct crash_elf_data *ced,
>  	phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
>  	(ehdr->e_phnum)++;
>  
> -#ifdef CONFIG_X86_64
>  	/* Prepare PT_LOAD type program header for kernel text region */
> -	phdr = (Elf64_Phdr *)bufp;
> -	bufp += sizeof(Elf64_Phdr);
> -	phdr->p_type = PT_LOAD;
> -	phdr->p_flags = PF_R|PF_W|PF_X;
> -	phdr->p_vaddr = (Elf64_Addr)_text;
> -	phdr->p_filesz = phdr->p_memsz = _end - _text;
> -	phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
> -	(ehdr->e_phnum)++;
> -#endif
> +	if (kernel_map) {
> +		phdr = (Elf64_Phdr *)bufp;
> +		bufp += sizeof(Elf64_Phdr);
> +		phdr->p_type = PT_LOAD;
> +		phdr->p_flags = PF_R|PF_W|PF_X;
> +		phdr->p_vaddr = (Elf64_Addr)_text;
> +		phdr->p_filesz = phdr->p_memsz = _end - _text;
> +		phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
> +		(ehdr->e_phnum)++;
> +	}
>  
>  	/* Go through all the ranges in cmem->ranges[] and prepare phdr */
>  	for (i = 0; i < cmem->nr_ranges; i++) {
> @@ -477,7 +477,8 @@ static int prepare_elf_headers(struct kimage *image, void **addr,
>  		goto out;
>  
>  	/* By default prepare 64bit headers */
> -	ret =  prepare_elf64_headers(ced, addr, sz);
> +	ret =  prepare_elf64_headers(ced,
> +				(int)IS_ENABLED(CONFIG_X86_64), addr, sz);

A bool would be enough for kernel_map

>  	if (ret)
>  		goto out;
>  

Thanks
Dave
> -- 
> 2.16.2
>
AKASHI Takahiro March 2, 2018, 5:33 a.m. UTC | #2 
On Fri, Mar 02, 2018 at 01:19:56PM +0800, Dave Young wrote:
> On 02/27/18 at 01:48pm, AKASHI Takahiro wrote:
> > The code guarded by CONFIG_X86_64 is necessary on some architectures
> > which have a dedicated kernel mapping outside of linear memory mapping.
> > (arm64 is among those.)
> > 
> > In this patch, an additional argument, kernel_map, is added to enable/
> > disable the code removing #ifdef.
> > 
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > Cc: Dave Young <dyoung@redhat.com>
> > Cc: Vivek Goyal <vgoyal@redhat.com>
> > Cc: Baoquan He <bhe@redhat.com>
> > ---
> >  arch/x86/kernel/crash.c | 25 +++++++++++++------------
> >  1 file changed, 13 insertions(+), 12 deletions(-)
> > 
> > diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> > index 2123fa0efc17..913fd8021f8a 100644
> > --- a/arch/x86/kernel/crash.c
> > +++ b/arch/x86/kernel/crash.c
> > @@ -347,7 +347,7 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
> >  	return 0;
> >  }
> >  
> > -static int prepare_elf64_headers(struct crash_elf_data *ced,
> > +static int prepare_elf64_headers(struct crash_elf_data *ced, int kernel_map,
> >  		void **addr, unsigned long *sz)
> >  {
> >  	Elf64_Ehdr *ehdr;
> > @@ -414,17 +414,17 @@ static int prepare_elf64_headers(struct crash_elf_data *ced,
> >  	phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
> >  	(ehdr->e_phnum)++;
> >  
> > -#ifdef CONFIG_X86_64
> >  	/* Prepare PT_LOAD type program header for kernel text region */
> > -	phdr = (Elf64_Phdr *)bufp;
> > -	bufp += sizeof(Elf64_Phdr);
> > -	phdr->p_type = PT_LOAD;
> > -	phdr->p_flags = PF_R|PF_W|PF_X;
> > -	phdr->p_vaddr = (Elf64_Addr)_text;
> > -	phdr->p_filesz = phdr->p_memsz = _end - _text;
> > -	phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
> > -	(ehdr->e_phnum)++;
> > -#endif
> > +	if (kernel_map) {
> > +		phdr = (Elf64_Phdr *)bufp;
> > +		bufp += sizeof(Elf64_Phdr);
> > +		phdr->p_type = PT_LOAD;
> > +		phdr->p_flags = PF_R|PF_W|PF_X;
> > +		phdr->p_vaddr = (Elf64_Addr)_text;
> > +		phdr->p_filesz = phdr->p_memsz = _end - _text;
> > +		phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
> > +		(ehdr->e_phnum)++;
> > +	}
> >  
> >  	/* Go through all the ranges in cmem->ranges[] and prepare phdr */
> >  	for (i = 0; i < cmem->nr_ranges; i++) {
> > @@ -477,7 +477,8 @@ static int prepare_elf_headers(struct kimage *image, void **addr,
> >  		goto out;
> >  
> >  	/* By default prepare 64bit headers */
> > -	ret =  prepare_elf64_headers(ced, addr, sz);
> > +	ret =  prepare_elf64_headers(ced,
> > +				(int)IS_ENABLED(CONFIG_X86_64), addr, sz);
> 
> A bool would be enough for kernel_map

Yeah, for now.
What I thought of is that we might want to extend its functionality
in the future as I did here for kernel_map without changing its interface.
But I'd defer to you.

-Takahiro AKASHI

> >  	if (ret)
> >  		goto out;
> >  
> 
> Thanks
> Dave
> > -- 
> > 2.16.2
> >
diff mbox

Patch

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 2123fa0efc17..913fd8021f8a 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -347,7 +347,7 @@  static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
 	return 0;
 }
 
-static int prepare_elf64_headers(struct crash_elf_data *ced,
+static int prepare_elf64_headers(struct crash_elf_data *ced, int kernel_map,
 		void **addr, unsigned long *sz)
 {
 	Elf64_Ehdr *ehdr;
@@ -414,17 +414,17 @@  static int prepare_elf64_headers(struct crash_elf_data *ced,
 	phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
 	(ehdr->e_phnum)++;
 
-#ifdef CONFIG_X86_64
 	/* Prepare PT_LOAD type program header for kernel text region */
-	phdr = (Elf64_Phdr *)bufp;
-	bufp += sizeof(Elf64_Phdr);
-	phdr->p_type = PT_LOAD;
-	phdr->p_flags = PF_R|PF_W|PF_X;
-	phdr->p_vaddr = (Elf64_Addr)_text;
-	phdr->p_filesz = phdr->p_memsz = _end - _text;
-	phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
-	(ehdr->e_phnum)++;
-#endif
+	if (kernel_map) {
+		phdr = (Elf64_Phdr *)bufp;
+		bufp += sizeof(Elf64_Phdr);
+		phdr->p_type = PT_LOAD;
+		phdr->p_flags = PF_R|PF_W|PF_X;
+		phdr->p_vaddr = (Elf64_Addr)_text;
+		phdr->p_filesz = phdr->p_memsz = _end - _text;
+		phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
+		(ehdr->e_phnum)++;
+	}
 
 	/* Go through all the ranges in cmem->ranges[] and prepare phdr */
 	for (i = 0; i < cmem->nr_ranges; i++) {
@@ -477,7 +477,8 @@  static int prepare_elf_headers(struct kimage *image, void **addr,
 		goto out;
 
 	/* By default prepare 64bit headers */
-	ret =  prepare_elf64_headers(ced, addr, sz);
+	ret =  prepare_elf64_headers(ced,
+				(int)IS_ENABLED(CONFIG_X86_64), addr, sz);
 	if (ret)
 		goto out;