diff mbox series

[v4] recordmcount: Correct st_shndx handling

Message ID 20210616154126.2794-1-mark-pk.tsai@mediatek.com (mailing list archive)
State New, archived
Headers show
Series [v4] recordmcount: Correct st_shndx handling | expand

Commit Message

Mark-PK Tsai June 16, 2021, 3:41 p.m. UTC
From: Peter Zijlstra <peterz@infradead.org>

One should only use st_shndx when >SHN_UNDEF and <SHN_LORESERVE. When
SHN_XINDEX, then use .symtab_shndx. Otherwise use 0.

This handles the case: st_shndx >= SHN_LORESERVE && st_shndx != SHN_XINDEX.

Reported-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
[handle endianness of sym->st_shndx]
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
---
 scripts/recordmcount.h | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

Comments

Steven Rostedt June 16, 2021, 4:02 p.m. UTC | #1
On Wed, 16 Jun 2021 23:41:26 +0800
Mark-PK Tsai <mark-pk.tsai@mediatek.com> wrote:

> From: Peter Zijlstra <peterz@infradead.org>
> 
> One should only use st_shndx when >SHN_UNDEF and <SHN_LORESERVE. When
> SHN_XINDEX, then use .symtab_shndx. Otherwise use 0.
> 
> This handles the case: st_shndx >= SHN_LORESERVE && st_shndx != SHN_XINDEX.
> 
> Reported-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
> [handle endianness of sym->st_shndx]
> Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
> ---

Thanks, I pulled this in and started the testing.

-- Steve
Steven Rostedt June 17, 2021, 12:23 a.m. UTC | #2
On Wed, 16 Jun 2021 12:02:27 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Wed, 16 Jun 2021 23:41:26 +0800
> Mark-PK Tsai <mark-pk.tsai@mediatek.com> wrote:
> 
> > From: Peter Zijlstra <peterz@infradead.org>
> > 
> > One should only use st_shndx when >SHN_UNDEF and <SHN_LORESERVE. When
> > SHN_XINDEX, then use .symtab_shndx. Otherwise use 0.
> > 
> > This handles the case: st_shndx >= SHN_LORESERVE && st_shndx != SHN_XINDEX.
> > 
> > Reported-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
> > [handle endianness of sym->st_shndx]
> > Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
> > ---  
> 
> Thanks, I pulled this in and started the testing.
> 

It passed my normal tests. I'll run my cross compile test, and I just
pushed it to linux-next. I'll wait a few days before I push it to Linus.

-- Steve
diff mbox series

Patch

diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h
index f9b19524da11..1e9baa5c4fc6 100644
--- a/scripts/recordmcount.h
+++ b/scripts/recordmcount.h
@@ -192,15 +192,20 @@  static unsigned int get_symindex(Elf_Sym const *sym, Elf32_Word const *symtab,
 				 Elf32_Word const *symtab_shndx)
 {
 	unsigned long offset;
+	unsigned short shndx = w2(sym->st_shndx);
 	int index;
 
-	if (sym->st_shndx != SHN_XINDEX)
-		return w2(sym->st_shndx);
+	if (shndx > SHN_UNDEF && shndx < SHN_LORESERVE)
+		return shndx;
 
-	offset = (unsigned long)sym - (unsigned long)symtab;
-	index = offset / sizeof(*sym);
+	if (shndx == SHN_XINDEX) {
+		offset = (unsigned long)sym - (unsigned long)symtab;
+		index = offset / sizeof(*sym);
 
-	return w(symtab_shndx[index]);
+		return w(symtab_shndx[index]);
+	}
+
+	return 0;
 }
 
 static unsigned int get_shnum(Elf_Ehdr const *ehdr, Elf_Shdr const *shdr0)