powerpc: unrel_branch_check.sh: enable the use of llvm-objdump v9, 10 or 11

Currently, using llvm-objtool, this script just silently succeeds without
actually do the intended checking. So this updates it to work properly.

Firstly, llvm-objdump does not add target symbol names to the end
of branches in its asm output, so we have to drop the branch to
__start_initialization_multiplatform using its address.

Secondly, v9 and 10 specify branch targets as .+<offset>, so we convert
those to actual addresses.

Thirdly, v10 and 11 error out on a vmlinux if given the -R option
complaining that it is "not a dynamic object". The -R does not make
any difference to the asm output, so remove it.

Lastly, v11 produces asm that is very similar to Gnu objtool (at least
as far as branches are concerned), so no further changes are necessary
to make it work.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200812081036.7969-3-sfr@canb.auug.org.au

powerpc: unrel_branch_check.sh: use nm to find symbol value

This is considerably faster then parsing the objdump asm output. It will
also make the enabling of llvm-objdump a little easier.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200812081036.7969-2-sfr@canb.auug.org.au

powerpc: unrel_branch_check.sh: exit silently for early errors

If we can't find the address of __end_interrupts, then we still exit
successfully as that is the current behaviour.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-8-sfr@canb.auug.org.au

powerpc: unrel_branch_check.sh: fix up the file header

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-7-sfr@canb.auug.org.au

powerpc: unrel_branch_check.sh: simplify and tidy up the final loop

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-6-sfr@canb.auug.org.au

powerpc: unrel_branch_check.sh: convert grep | sed | awk to just sed

Also start using sed -E and make all the separate expressions into a
single one with comments. Pull the stripping of condition registers
back into the sed command.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-5-sfr@canb.auug.org.au

powerpc: unrel_branch_check.sh: simplify objdump's asm output

We don't use the raw hex instruction dump, so elide it and adjust the
following expressions.

Also use \s instead of [[:space:]] everywhere.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-4-sfr@canb.auug.org.au

powerpc: unrel_branch_check.sh: simplify and combine some executions

Also some minor style changes.

There should still be no change in behaviour.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-3-sfr@canb.auug.org.au

powerpc: unrel_branch_check.sh: fix shellcheck complaints

No functional change

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200811140435.20957-2-sfr@canb.auug.org.au

powerpc/64s: allow for clang's objdump differences

Clang's objdump emits slightly different output from GNU's objdump,
causing a list of warnings to be emitted during relocatable builds.
E.g., clang's objdump emits this:

c000000000000004: 2c 00 00 48 b 0xc000000000000030
...
c000000000005c6c: 10 00 82 40 bf 2, 0xc000000000005c7c

while GNU objdump emits:

c000000000000004: 2c 00 00 48 b c000000000000030 <__start+0x30>
...
c000000000005c6c: 10 00 82 40 bne c000000000005c7c <masked_interrupt+0x3c>

Adjust llvm-objdump's output to remove the extraneous '0x' and convert
'bf' and 'bt' to 'bne' and 'beq' resp. to more closely match GNU
objdump's output.

Note that clang's objdump doesn't yet output the relocation symbols on
PPC.

Signed-off-by: Bill Wendling <morbo@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/191c67db31264b69cf6b566fd69851beb3dd0abb.1595630874.git.morbo@google.com

powerpc/tools: Don't quote $objdump in scripts

Some of our scripts are passed $objdump and then call it as
"$objdump". This doesn't work if it contains spaces because we're
using ccache, for example you get errors such as:

./arch/powerpc/tools/relocs_check.sh: line 48: ccache ppc64le-objdump: No such file or directory
./arch/powerpc/tools/unrel_branch_check.sh: line 26: ccache ppc64le-objdump: No such file or directory

Fix it by not quoting the string when we expand it, allowing the shell
to do the right thing for us.

Fixes: a71aa05e1416 ("powerpc: Convert relocs_check to a shell script using grep")
Fixes: 4ea80652dc75 ("powerpc/64s: Tool to flag direct branches from unrelocated interrupt vectors")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024004730.32135-1-mpe@ellerman.id.au

powerpc/64s: Tool to flag direct branches from unrelocated interrupt vectors

Direct banches from code below __end_interrupts to code above
__end_interrupts when built with CONFIG_RELOCATABLE are disallowed
because they will break when the kernel is not located at 0.

Sample output:

WARNING: Unrelocated relative branches
c000000000000118 bl-> 0xc000000000038fb8 <pnv_restore_hyp_resource>
c00000000000013c b-> 0xc0000000001068a4 <kvm_start_guest>
c000000000000148 b-> 0xc00000000003919c <pnv_wakeup_loss>
c00000000000014c b-> 0xc00000000003923c <pnv_wakeup_noloss>
c0000000000005a4 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
c000000000001af0 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
c000000000001b24 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>
c000000000001b58 b-> 0xc000000000106ffc <kvmppc_interrupt_hv>

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>