Fix wrong size calculation for "Dx ?" larger than DB #19
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The size calculation done in len_extops() (called by insn_size()) for
EOT_DB_RESERVE (i.e. uninitialized storage "?" token) does not take
into account the element size (e->elem), thus calculating a wrong
size for any Dx larger than DB (DW, DQ, etc).
The bug is silent, but it makes NASM error out if a "Dx ?" (larger
than DB) is followed by any label because the label offset gets
mismatched in the final code generation stage:
$ cat test.asm
[section .bss]
DW ?
x:
$ nasm test.asm
test.asm:3: error: label `x' changed during code generation [-w+error=label-redef-late]
See also: https://stackoverflow.com/q/70012188/3889449
Signed-off-by: Marco Bonelli <marco@mebeim.net>
Contributor
|
Looks reasonable, thanks! A couple of days to review. |
Contributor
|
merged into master as d167b3d |
Contributor
Author
|
Hi @cyrillos I see you also implemented a simple test that is supposed to run on Travis CI for this. However you have this repo registered under travis-ci.org, and their website reads:
In fact, the last Travis build from this project was around 6 months ago. You should probably swap to the .com domain if you want your tests to actually run. Just wanted to let you know in case you weren't aware. |
Contributor
|
Thanks for pointing! Will take a look once time permit |
sorokin
added a commit
to sorokin/nasm
that referenced
this pull request
Feb 26, 2023
When running with -fsanitize=leak enabled nasm prints this error:
==19965==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 360 byte(s) in 90 object(s) allocated from:
#0 0x7faee9396867 in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
netwide-assembler#1 0x5645d39a401c in nasm_malloc nasmlib/alloc.c:55
netwide-assembler#2 0x5645d3a41f9d in string_transform asm/strfunc.c:356
netwide-assembler#3 0x5645d3a37d40 in eval_strfunc asm/eval.c:761
netwide-assembler#4 0x5645d3a37d40 in expr6 asm/eval.c:906
netwide-assembler#5 0x5645d3a3968d in expr5 asm/eval.c:627
netwide-assembler#6 0x5645d3a39aca in expr4 asm/eval.c:602
netwide-assembler#7 0x5645d3a39b72 in expr3 asm/eval.c:563
netwide-assembler#8 0x5645d3a39db8 in expr2 asm/eval.c:537
netwide-assembler#9 0x5645d3a39f38 in expr1 asm/eval.c:511
netwide-assembler#10 0x5645d3a3a0b8 in expr0 asm/eval.c:485
netwide-assembler#11 0x5645d3a3a242 in rexp3 asm/eval.c:422
netwide-assembler#12 0x5645d3a3a508 in rexp2 asm/eval.c:396
netwide-assembler#13 0x5645d3a3a6a8 in rexp1 asm/eval.c:369
netwide-assembler#14 0x5645d3a3a838 in rexp0 asm/eval.c:342
netwide-assembler#15 0x5645d3a3a838 in cexpr asm/eval.c:305
netwide-assembler#16 0x5645d3a3ad08 in bexpr asm/eval.c:298
netwide-assembler#17 0x5645d3a3ad08 in evaluate asm/eval.c:1032
netwide-assembler#18 0x5645d39e4f20 in parse_line asm/parser.c:959
netwide-assembler#19 0x5645d399e243 in assemble_file asm/nasm.c:1735
netwide-assembler#20 0x5645d3998801 in main asm/nasm.c:719
netwide-assembler#21 0x7faee8aaed8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
netwide-assembler#22 0x7faee8aaee3f in __libc_start_main_impl ../csu/libc-start.c:392
netwide-assembler#23 0x5645d399acd4 in _start (/home/ivan/d/nasm/nasm+0x2e5cd4)
SUMMARY: AddressSanitizer: 360 byte(s) leaked in 90 allocation(s).
This problem is reproducible on test utf.asm.
The problem was caused by the fact that eval_strfunc doesn't free the string
allocated by string_transform.
sorokin
added a commit
to sorokin/nasm
that referenced
this pull request
Mar 5, 2023
When running with -fsanitize=leak enabled nasm prints this error:
==19965==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 360 byte(s) in 90 object(s) allocated from:
#0 0x7faee9396867 in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
netwide-assembler#1 0x5645d39a401c in nasm_malloc nasmlib/alloc.c:55
netwide-assembler#2 0x5645d3a41f9d in string_transform asm/strfunc.c:356
netwide-assembler#3 0x5645d3a37d40 in eval_strfunc asm/eval.c:761
netwide-assembler#4 0x5645d3a37d40 in expr6 asm/eval.c:906
netwide-assembler#5 0x5645d3a3968d in expr5 asm/eval.c:627
netwide-assembler#6 0x5645d3a39aca in expr4 asm/eval.c:602
netwide-assembler#7 0x5645d3a39b72 in expr3 asm/eval.c:563
netwide-assembler#8 0x5645d3a39db8 in expr2 asm/eval.c:537
netwide-assembler#9 0x5645d3a39f38 in expr1 asm/eval.c:511
netwide-assembler#10 0x5645d3a3a0b8 in expr0 asm/eval.c:485
netwide-assembler#11 0x5645d3a3a242 in rexp3 asm/eval.c:422
netwide-assembler#12 0x5645d3a3a508 in rexp2 asm/eval.c:396
netwide-assembler#13 0x5645d3a3a6a8 in rexp1 asm/eval.c:369
netwide-assembler#14 0x5645d3a3a838 in rexp0 asm/eval.c:342
netwide-assembler#15 0x5645d3a3a838 in cexpr asm/eval.c:305
netwide-assembler#16 0x5645d3a3ad08 in bexpr asm/eval.c:298
netwide-assembler#17 0x5645d3a3ad08 in evaluate asm/eval.c:1032
netwide-assembler#18 0x5645d39e4f20 in parse_line asm/parser.c:959
netwide-assembler#19 0x5645d399e243 in assemble_file asm/nasm.c:1735
netwide-assembler#20 0x5645d3998801 in main asm/nasm.c:719
netwide-assembler#21 0x7faee8aaed8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
netwide-assembler#22 0x7faee8aaee3f in __libc_start_main_impl ../csu/libc-start.c:392
netwide-assembler#23 0x5645d399acd4 in _start (/home/ivan/d/nasm/nasm+0x2e5cd4)
SUMMARY: AddressSanitizer: 360 byte(s) leaked in 90 allocation(s).
This problem is reproducible on test utf.asm.
The problem was caused by the fact that eval_strfunc doesn't free the string
allocated by string_transform.
Signed-off-by: Ivan Sorokin <vanyacpp@gmail.com>
hpax
pushed a commit
that referenced
this pull request
Oct 6, 2025
When running with -fsanitize=leak enabled nasm prints this error:
==19965==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 360 byte(s) in 90 object(s) allocated from:
#0 0x7faee9396867 in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
#1 0x5645d39a401c in nasm_malloc nasmlib/alloc.c:55
#2 0x5645d3a41f9d in string_transform asm/strfunc.c:356
#3 0x5645d3a37d40 in eval_strfunc asm/eval.c:761
#4 0x5645d3a37d40 in expr6 asm/eval.c:906
#5 0x5645d3a3968d in expr5 asm/eval.c:627
#6 0x5645d3a39aca in expr4 asm/eval.c:602
#7 0x5645d3a39b72 in expr3 asm/eval.c:563
#8 0x5645d3a39db8 in expr2 asm/eval.c:537
#9 0x5645d3a39f38 in expr1 asm/eval.c:511
#10 0x5645d3a3a0b8 in expr0 asm/eval.c:485
#11 0x5645d3a3a242 in rexp3 asm/eval.c:422
#12 0x5645d3a3a508 in rexp2 asm/eval.c:396
#13 0x5645d3a3a6a8 in rexp1 asm/eval.c:369
#14 0x5645d3a3a838 in rexp0 asm/eval.c:342
#15 0x5645d3a3a838 in cexpr asm/eval.c:305
#16 0x5645d3a3ad08 in bexpr asm/eval.c:298
#17 0x5645d3a3ad08 in evaluate asm/eval.c:1032
#18 0x5645d39e4f20 in parse_line asm/parser.c:959
#19 0x5645d399e243 in assemble_file asm/nasm.c:1735
#20 0x5645d3998801 in main asm/nasm.c:719
#21 0x7faee8aaed8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#22 0x7faee8aaee3f in __libc_start_main_impl ../csu/libc-start.c:392
#23 0x5645d399acd4 in _start (/home/ivan/d/nasm/nasm+0x2e5cd4)
SUMMARY: AddressSanitizer: 360 byte(s) leaked in 90 allocation(s).
This problem is reproducible on test utf.asm.
The problem was caused by the fact that eval_strfunc doesn't free the string
allocated by string_transform.
Signed-off-by: Ivan Sorokin <vanyacpp@gmail.com>
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The size calculation done in
len_extops()(called byinsn_size()) forEOT_DB_RESERVE(i.e. uninitialized storage?token) does not take into account the element size (e->elem), thus calculating a wrong size for any Dx larger than DB (DW, DQ, etc).The bug is silent, but it makes NASM error out if a "Dx ?" (larger than DB) is followed by any label because the label offset gets mismatched in the final code generation stage:
See also this StackOverflow question complaining about the problem.