[PATCH] common: elf: use proper field to get segment memory size

[PATCH] common: elf: use proper field to get segment memory size

[Denis Orlov]

For a program header, the value of 'p_filesz' may be less than the one
of 'p_memsz', in which case the leftover amount of space should be
filled with zeroes. This is done correctly when loading elf to memory.
However, when we are requesting memory beforehand we do pass the value
of 'p_filesz', instead of 'p_memsz', to 'request_sdram_region',
resulting in potentially smaller amount of memory to be reserved.

As 'p_memsz' is always greater or equal to 'p_filesz', use only the
former for checking memory requirements in 'request_elf_segment'.

Signed-off-by: Denis Orlov <denorl2009@gmail.com>
---
 common/elf.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/common/elf.c b/common/elf.c
index eec62cad61..c9b3d7bb37 100644
--- a/common/elf.c
+++ b/common/elf.c
@@ -59,14 +59,13 @@ static int request_elf_segment(struct elf_image *elf, void *phdr)
 {
 	void *dst = (void *) (phys_addr_t) elf_phdr_p_paddr(elf, phdr);
 	int ret;
-	u64 p_filesz = elf_phdr_p_filesz(elf, phdr);
 	u64 p_memsz = elf_phdr_p_memsz(elf, phdr);
 
 	/* we care only about PT_LOAD segments */
 	if (elf_phdr_p_type(elf, phdr) != PT_LOAD)
 		return 0;
 
-	if (!p_filesz)
+	if (!p_memsz)
 		return 0;
 
 	if (dst < elf->low_addr)
@@ -74,9 +73,9 @@ static int request_elf_segment(struct elf_image *elf, void *phdr)
 	if (dst + p_memsz > elf->high_addr)
 		elf->high_addr = dst + p_memsz;
 
-	pr_debug("Requesting segment 0x%p (%llu bytes)\n", dst, p_filesz);
+	pr_debug("Requesting segment 0x%p (%llu bytes)\n", dst, p_memsz);
 
-	ret = elf_request_region(elf, (resource_size_t)dst, p_filesz, phdr);
+	ret = elf_request_region(elf, (resource_size_t)dst, p_memsz, phdr);
 	if (ret)
 		return ret;
 
-- 
2.30.2

Re: [PATCH] common: elf: use proper field to get segment memory size

[Sascha Hauer]

On Wed, Mar 15, 2023 at 01:11:26PM +0300, Denis Orlov wrote:
> For a program header, the value of 'p_filesz' may be less than the one
> of 'p_memsz', in which case the leftover amount of space should be
> filled with zeroes. This is done correctly when loading elf to memory.
> However, when we are requesting memory beforehand we do pass the value
> of 'p_filesz', instead of 'p_memsz', to 'request_sdram_region',
> resulting in potentially smaller amount of memory to be reserved.
> 
> As 'p_memsz' is always greater or equal to 'p_filesz', use only the
> former for checking memory requirements in 'request_elf_segment'.
> 
> Signed-off-by: Denis Orlov <denorl2009@gmail.com>
> ---
>  common/elf.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)

Applied, thanks

Sascha

> 
> diff --git a/common/elf.c b/common/elf.c
> index eec62cad61..c9b3d7bb37 100644
> --- a/common/elf.c
> +++ b/common/elf.c
> @@ -59,14 +59,13 @@ static int request_elf_segment(struct elf_image *elf, void *phdr)
>  {
>  	void *dst = (void *) (phys_addr_t) elf_phdr_p_paddr(elf, phdr);
>  	int ret;
> -	u64 p_filesz = elf_phdr_p_filesz(elf, phdr);
>  	u64 p_memsz = elf_phdr_p_memsz(elf, phdr);
>  
>  	/* we care only about PT_LOAD segments */
>  	if (elf_phdr_p_type(elf, phdr) != PT_LOAD)
>  		return 0;
>  
> -	if (!p_filesz)
> +	if (!p_memsz)
>  		return 0;
>  
>  	if (dst < elf->low_addr)
> @@ -74,9 +73,9 @@ static int request_elf_segment(struct elf_image *elf, void *phdr)
>  	if (dst + p_memsz > elf->high_addr)
>  		elf->high_addr = dst + p_memsz;
>  
> -	pr_debug("Requesting segment 0x%p (%llu bytes)\n", dst, p_filesz);
> +	pr_debug("Requesting segment 0x%p (%llu bytes)\n", dst, p_memsz);
>  
> -	ret = elf_request_region(elf, (resource_size_t)dst, p_filesz, phdr);
> +	ret = elf_request_region(elf, (resource_size_t)dst, p_memsz, phdr);
>  	if (ret)
>  		return ret;
>  
> -- 
> 2.30.2
> 
> 

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